Chpt 2. Protozoans 11-26

Question 1

Question and Options

Answer 1

Answer and Explanation

Question 2

What is the causative organism of malaria? a) Trypanosoma b) Plasmodium c) Leishmania d) Entamoeba

Answer 2

Answer: b) Plasmodium Explanation: Malaria is caused by protozoa of the genus Plasmodium. There are several species, including Plasmodium falciparum, which is the most virulent.

Question 3

What type of malaria is caused by Plasmodium falciparum? a) Benign tertian malaria b) Quartan malaria c) Malignant tertian malaria d) Ovale malaria

Answer 3

Answer: c) Malignant tertian malaria Explanation: Plasmodium falciparum causes malignant tertian malaria, which is severe and often life-threatening compared to other forms of malaria.

Question 4

Which mosquito is responsible for transmitting malaria? a) Aedes b) Culex c) Anopheles d) Mansonia

Answer 4

Answer: c) Anopheles Explanation: Malaria is transmitted by the bite of an infected female Anopheles mosquito.

Question 5

What is the periodicity of fever in Plasmodium vivax malaria? a) Every 24 hours b) Every 48 hours c) Every 72 hours d) Every 96 hours

Answer 5

Answer: b) Every 48 hours Explanation: In P. vivax infections, fever recurs every 48 hours, giving it the name tertian malaria.

Question 6

In which organ do Plasmodium species first develop after infection? a) Heart b) Brain c) Liver d) Spleen

Answer 6

Answer: c) Liver Explanation: Plasmodium sporozoites first infect the liver cells, where they undergo the exoerythrocytic schizogony phase before entering the bloodstream.

Question 7

What type of malaria is characterized by relapses years after the initial infection? a) Plasmodium falciparum b) Plasmodium vivax c) Plasmodium malariae d) Plasmodium ovale

Answer 7

Answer: b) Plasmodium vivax Explanation: Plasmodium vivax can cause relapses due to the presence of dormant liver forms called hypnozoites, which can activate years after the initial infection.

Question 8

What cellular structure in Plasmodium falciparum malaria causes sequestration of infected red blood cells? a) Schuffner’s dots b) Maurer’s clefts c) Chromatoid bodies d) Trophozoites

Answer 8

Answer: b) Maurer’s clefts Explanation: P. falciparum-infected red blood cells develop Maurer’s clefts, which contribute to their sequestration in small blood vessels, leading to severe complications.

Question 9

What is the most common complication of Plasmodium falciparum infection? a) Hemorrhage b) Hepatomegaly c) Cerebral malaria d) Nephritis

Answer 9

Answer: c) Cerebral malaria Explanation: P. falciparum often causes cerebral malaria due to the sequestration of infected red blood cells in the brain capillaries, leading to severe neurological symptoms.

Question 10

What is the primary mode of malaria transmission? a) Blood transfusion b) Mosquito bite c) Contaminated water d) Contact with an infected person

Answer 10

Answer: b) Mosquito bite Explanation: Malaria is primarily transmitted through the bite of an infected female Anopheles mosquito, which injects sporozoites into the bloodstream.

Question 11

Which type of malaria is known for its 72-hour fever cycle? a) Plasmodium vivax b) Plasmodium malariae c) Plasmodium falciparum d) Plasmodium ovale

Answer 11

Answer: b) Plasmodium malariae Explanation: P. malariae causes quartan malaria, where fever paroxysms occur every 72 hours.

Question 12

Which of the following species causes the rarest form of malaria? a) Plasmodium falciparum b) Plasmodium vivax c) Plasmodium malariae d) Plasmodium ovale

Answer 12

Answer: d) Plasmodium ovale Explanation: P. ovale is the rarest human malaria parasite, mostly confined to the tropics.

Question 13

In Plasmodium falciparum infection, which age group of erythrocytes is invaded by merozoites? a) Only mature erythrocytes b) Only reticulocytes c) Erythrocytes of any age d) Only aging erythrocytes

Answer 13

Answer: c) Erythrocytes of any age Explanation: In P. falciparum malaria, merozoites can invade erythrocytes of any age, contributing to higher levels of parasitemia.

Question 14

How long does the sexual stage of Plasmodium falciparum take to develop? a) 5 days b) 7 days c) 10 days d) 15 days

Answer 14

Answer: c) 10 days Explanation: In P. falciparum infection, the sexual stages (gametocytes) require about 10 days to develop.

Question 15

What is a key feature distinguishing Plasmodium vivax merozoites from Plasmodium falciparum? a) They invade all erythrocytes b) They invade only mature erythrocytes c) They invade only young erythrocytes (reticulocytes) d) They invade endothelial cells

Answer 15

Answer: c) They invade only young erythrocytes (reticulocytes) Explanation: P. vivax merozoites can only invade young erythrocytes (reticulocytes), unlike P. falciparum, which can invade erythrocytes of any age.

Question 16

What immune system component is responsible for the phagocytosis of infected erythrocytes in malaria? a) Neutrophils b) Macrophages c) T-cells d) B-cells

Answer 16

Answer: b) Macrophages Explanation: Infected erythrocytes in malaria are phagocytosed by macrophages, particularly in the spleen.

Question 17

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Answer 17

Answer & Explanation

Question 18

What immune system component is responsible for the phagocytosis of infected erythrocytes in malaria?\na) Neutrophils\nb) Macrophages\nc) T-cells\nd) B-cells

Answer 18

Answer: b) Macrophages\nExplanation: Infected erythrocytes in malaria are phagocytosed by macrophages, particularly in the spleen.

Question 19

Which of the following is NOT a feature of Plasmodium falciparum malaria?\na) High parasitemia\nb) Relapses after treatment\nc) Cerebral complications\nd) Sequestration of red blood cells

Answer 19

Answer: b) Relapses after treatment\nExplanation: Relapses are not characteristic of P. falciparum malaria, but recrudescence may occur due to incomplete elimination of the parasite.

Question 20

What is the primary pathological effect of malaria infection?\na) Inflammation\nb) Hyperglycemia\nc) Anemia\nd) Dehydration

Answer 20

Answer: c) Anemia\nExplanation: Malaria primarily causes anemia due to the destruction of red blood cells, both parasitized and non-parasitized.

Question 21

How is Plasmodium vivax naturally resistant in many African populations?\na) Due to absence of Duffy antigen\nb) Due to sickle cell trait\nc) Due to high antibody levels\nd) Due to rapid erythropoiesis

Answer 21

Answer: a) Due to absence of Duffy antigen\nExplanation: Many African populations are resistant to P. vivax because their red blood cells lack the Duffy antigen, which the parasite requires to enter the cells.

Question 22

Which Plasmodium species can cause infection after a blood transfusion decades after initial infection?\na) Plasmodium falciparum\nb) Plasmodium vivax\nc) Plasmodium malariae\nd) Plasmodium ovale

Answer 22

Answer: c) Plasmodium malariae\nExplanation: P. malariae can persist in the blood for decades and is a common cause of transfusion-related malaria.

Question 23

What is the primary host organ affected during the exoerythrocytic phase of Plasmodium infection?\na) Heart\nb) Liver\nc) Lungs\nd) Kidneys

Answer 23

Answer: b) Liver\nExplanation: The exoerythrocytic phase of malaria occurs in the liver, where the parasite undergoes development before entering the bloodstream.

Question 24

Which of the following Plasmodium species is primarily responsible for tertian malaria?\na) Plasmodium falciparum\nb) Plasmodium vivax\nc) Plasmodium ovale\nd) Plasmodium malariae

Answer 24

Answer: b) Plasmodium vivax\nExplanation: Plasmodium vivax causes benign tertian malaria, characterized by fever paroxysms every 48 hours, a periodicity referred to as tertian.

Question 25

How long can recrudescence occur in Plasmodium malariae infection?\na) 3 months\nb) 1 year\nc) 10 years\nd) 53 years

Answer 25

Answer: d) 53 years\nExplanation: Recrudescence of Plasmodium malariae can occur up to 53 years after the initial infection due to the parasite’s long persistence in the bloodstream.

Question 26

Which malaria-causing species is least common?\na) Plasmodium falciparum\nb) Plasmodium vivax\nc) Plasmodium ovale\nd) Plasmodium malariae

Answer 26

Answer: c) Plasmodium ovale\nExplanation: Plasmodium ovale is the rarest of the four human malaria parasites, primarily confined to tropical regions.

Question 27

What is the primary manifestation of malaria on red blood cells?\na) Enlargement of the erythrocytes\nb) Destruction of parasitized and non-parasitized erythrocytes\nc) Formation of Schuffner’s dots\nd) Binding to lymphocytes

Answer 27

Answer: b) Destruction of parasitized and non-parasitized erythrocytes\nExplanation: Malaria causes the destruction of erythrocytes, which can lead to anemia and other severe complications.

Question 28

In severe falciparum malaria, what may happen to parasitized erythrocytes?\na) They may adhere to endothelial cells\nb) They may shrink and disappear\nc) They may mutate into another species\nd) They may become resistant to treatment

Answer 28

Answer: a) They may adhere to endothelial cells\nExplanation: In Plasmodium falciparum infection, parasitized erythrocytes tend to adhere to the capillary endothelium, leading to the clogging of blood vessels.

Question 29

Which organ primarily phagocytoses malaria-infected erythrocytes?\na) Liver\nb) Spleen\nc) Brain\nd) Kidney

Answer 29

Answer: b) Spleen\nExplanation: The spleen is responsible for phagocytosing parasitized erythrocytes, leading to its enlargement (splenomegaly) in malaria patients.

Question 30

Which malaria species exhibits a relapsing pattern up to 8 years after infection?\na) Plasmodium vivax\nb) Plasmodium falciparum\nc) Plasmodium malariae\nd) Plasmodium ovale

Answer 30

Answer: a) Plasmodium vivax\nExplanation: Plasmodium vivax can cause relapses up to 8 years after the initial infection due to the presence of dormant hypnozoites in the liver.

Question 31

What is the term used for the periodic recurrence of malaria symptoms?\na) Incubation\nb) Relapse\nc) Paroxysm\nd) Sporulation

Answer 31

Answer: c) Paroxysm\nExplanation: Paroxysm refers to the periodic recurrence of fever and other symptoms in malaria, often timed with the release of merozoites into the bloodstream.

Question 32

What is the characteristic shape of a mature schizont of Plasmodium ovale?\na) Oval or spherical\nb) Irregular and amoeboid\nc) Ring-like\nd) Star-shaped

Answer 32

Answer: a) Oval or spherical\nExplanation: The mature schizont of Plasmodium ovale typically has an oval or spherical shape, producing 4 to 16 merozoites.

Question 33

In Plasmodium falciparum infection, what occurs when parasitized erythrocytes form ‘rosettes’?\na) They invade the liver\nb) They bind to uninfected red cells\nc) They undergo apoptosis\nd) They replicate uncontrollably

Answer 33

Answer: b) They bind to uninfected red cells\nExplanation: In Plasmodium falciparum malaria, infected erythrocytes can bind to uninfected red cells, forming rosettes, which can obstruct blood vessels.

Question 34

Which malaria species has a characteristic stippling called Schuffner’s dots?\na) Plasmodium falciparum\nb) Plasmodium malariae\nc) Plasmodium vivax\nd) Plasmodium ovale

Answer 34

Answer: c) Plasmodium vivax\nExplanation: Plasmodium vivax trophozoites are associated with Schuffner’s dots, which are distinct stipplings seen in infected erythrocytes.

Question 35

What is the most dangerous form of malaria?\na) Plasmodium vivax malaria\nb) Plasmodium ovale malaria\nc) Plasmodium malariae malaria\nd) Plasmodium falciparum malaria

Answer 35

Answer: d) Plasmodium falciparum malaria\nExplanation: Plasmodium falciparum malaria is the most virulent and potentially fatal, responsible for severe complications such as cerebral malaria.

Question 36

Which malaria species is most common in tropical Africa?\na) Plasmodium vivax\nb) Plasmodium falciparum\nc) Plasmodium ovale\nd) Plasmodium malariae

Answer 36

Answer: b) Plasmodium falciparum\nExplanation: Plasmodium falciparum is the most common malaria species in tropical Africa and is responsible for the highest mortality rates.

Question 37

What is the primary site of exoerythrocytic schizogony in malaria?\na) Bone marrow\nb) Lymph nodes\nc) Liver\nd) Spleen

Answer 37

Answer: c) Liver\nExplanation: Exoerythrocytic schizogony occurs in the liver, where sporozoites mature into schizonts before releasing merozoites into the bloodstream.

Question 38

Which malaria-causing species invades only young erythrocytes (reticulocytes)?\na) Plasmodium falciparum\nb) Plasmodium malariae\nc) Plasmodium vivax\nd) Plasmodium ovale

Answer 38

Answer: c) Plasmodium vivax\nExplanation: Plasmodium vivax merozoites can only invade young red blood cells (reticulocytes), limiting its parasitemia levels compared to other species.

Question 39

What is a significant feature of blackwater fever associated with Plasmodium falciparum?\na) Vomiting\nb) Anaemia\nc) Hemoglobinuria\nd) Cerebral impairment

Answer 39

Answer: c) Hemoglobinuria\nExplanation: Blackwater fever is characterized by hemoglobinuria (presence of hemoglobin in urine), a complication of severe Plasmodium falciparum malaria.

Question 40

What symptom is more prominent in Plasmodium falciparum infection compared to other malaria species?\na) Lymph node swelling\nb) Severe headache\nc) Increased parasitemia\nd) Rapid heart rate

Answer 40

“Answer: c) Increased parasitemia\nExplanation: Plasmodium falciparum causes higher

Question 41

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Answer 41

Answer & Explanation

Question 42

How long does it take for gametocytes of Plasmodium vivax to appear in peripheral blood?\na) 5 days\nb) 4 days\nc) 10 days\nd) Almost immediately

Answer 42

Answer: d) Almost immediately\nExplanation: In Plasmodium vivax infection, gametocytes may appear in peripheral blood almost at the same time as trophozoites.

Question 43

Which form of malaria may remain dormant in the liver as hypnozoites?\na) Plasmodium falciparum\nb) Plasmodium malariae\nc) Plasmodium vivax\nd) Plasmodium ovale

Answer 43

Answer: c) Plasmodium vivax\nExplanation: Plasmodium vivax and Plasmodium ovale can form hypnozoites that remain dormant in the liver, leading to relapses.

Question 44

What is the appearance of the spleen during acute malaria?\na) Small and firm\nb) Enlarged and congested\nc) Soft and pale\nd) Normal-sized but fibrous

Answer 44

Answer: b) Enlarged and congested\nExplanation: In acute malaria, the spleen becomes enlarged and congested due to the phagocytosis of parasitized red blood cells.

Question 45

Which symptom is typically NOT associated with malaria?\na) Splenomegaly\nb) Diarrhea\nc) Fever\nd) Anaemia

Answer 45

Answer: b) Diarrhea\nExplanation: Diarrhea is not a common symptom of malaria; fever, splenomegaly, and anemia are more characteristic.

Question 46

How long is the usual intrinsic incubation period for Plasmodium vivax?\na) 7-9 days\nb) 10-17 days\nc) 20-30 days\nd) 1-3 months

Answer 46

Answer: b) 10-17 days\nExplanation: The intrinsic incubation period for Plasmodium vivax, the time between the bite of an infected mosquito and the appearance of clinical symptoms, is typically 10-17 days.

Question 47

Which of the following is the most common complication of severe malaria caused by Plasmodium falciparum?\na) Hepatitis\nb) Acute renal failure\nc) Cerebral malaria\nd) Pneumonia

Answer 47

Answer: c) Cerebral malaria\nExplanation: Cerebral malaria is the most serious complication of Plasmodium falciparum infection, leading to impaired consciousness, seizures, and potentially death.

Question 48

Which organ does Plasmodium falciparum primarily affect during cerebral malaria?\na) Liver\nb) Kidneys\nc) Brain\nd) Spleen

Answer 48

Answer: c) Brain\nExplanation: Cerebral malaria is a severe manifestation of Plasmodium falciparum infection where parasitized red blood cells clog brain capillaries, causing neurological symptoms.

Question 49

Which of the following drugs is most effective for treating the liver stage (hypnozoites) of Plasmodium vivax?\na) Chloroquine\nb) Primaquine\nc) Mefloquine\nd) Quinine

Answer 49

Answer: b) Primaquine\nExplanation: Primaquine is effective against the dormant liver stages (hypnozoites) of Plasmodium vivax and Plasmodium ovale, preventing relapse.

Question 50

What stage of Plasmodium falciparum is responsible for causing the characteristic fever paroxysms in malaria?\na) Sporozoites\nb) Gametocytes\nc) Trophozoites\nd) Merozoites

Answer 50

Answer: d) Merozoites\nExplanation: Merozoites are released from infected red blood cells during schizogony, triggering the immune response that causes fever paroxysms.

Question 51

What type of anemia is typically associated with severe malaria?\na) Aplastic anemia\nb) Hemolytic anemia\nc) Iron deficiency anemia\nd) Megaloblastic anemia

Answer 51

Answer: b) Hemolytic anemia\nExplanation: Hemolytic anemia is common in malaria due to the destruction of parasitized and non-parasitized red blood cells.

Question 52

What is the method of choice for diagnosing malaria in a clinical setting?\na) Rapid antigen test\nb) Blood culture\nc) Peripheral blood smear\nd) Serology

Answer 52

Answer: c) Peripheral blood smear\nExplanation: A peripheral blood smear remains the gold standard for malaria diagnosis, allowing direct visualization of the parasite in red blood cells.

Question 53

What vector transmits malaria?\na) Aedes mosquitoes\nb) Anopheles mosquitoes\nc) Culex mosquitoes\nd) Ticks

Answer 53

Answer: b) Anopheles mosquitoes\nExplanation: Malaria is transmitted by female Anopheles mosquitoes, which inject Plasmodium sporozoites into the bloodstream during feeding.

Question 54

Which population is at the highest risk for severe complications from malaria?\na) Healthy adults\nb) Pregnant women\nc) Young males\nd) Adolescents

Answer 54

Answer: b) Pregnant women\nExplanation: Pregnant women are at higher risk for severe complications from malaria due to decreased immunity, and infection can affect both mother and fetus.

Question 55

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Answer 55

Answer & Explanation

Question 56

In quartan malaria (P. malariae), how frequently do the attacks occur?\na) Every 24 hours\nb) Every 48 hours\nc) Every 72 hours\nd) Every 96 hours

Answer 56

Answer: c) Every 72 hours\nExplanation: In quartan malaria, caused by P. malariae, the attacks occur every 72 hours if only a single brood of parasites is present.

Question 57

What is a common complication of any type of malaria?\na) Anaemia\nb) Pulmonary oedema\nc) Hypoglycemia\nd) Blackwater fever

Answer 57

Answer: a) Anaemia\nExplanation: Anaemia is a frequent complication of all types of malaria due to the destruction of red blood cells by the parasite.

Question 58

Which type of malaria is associated with splenic rupture?\na) P. falciparum\nb) P. malariae\nc) P. vivax\nd) P. ovale

Answer 58

Answer: c) P. vivax\nExplanation: Splenic rupture is a complication seen in P. vivax malaria (benign tertian), but it is rare.

Question 59

Nephrosis, characterized by large amounts of albumin in the urine, is commonly associated with which type of malaria?\na) P. falciparum\nb) P. malariae\nc) P. vivax\nd) P. ovale

Answer 59

Answer: b) P. malariae\nExplanation: Chronic P. malariae infection is often linked to nephrosis, leading to proteinuria (albumin in the urine).

Question 60

What symptom is more pronounced in P. falciparum malaria compared to other types of malaria?\na) Prostration\nb) Fever paroxysms\nc) Sweating\nd) Joint pain

Answer 60

Answer: a) Prostration\nExplanation: Prostration and a greater tendency to delirium are more pronounced in P. falciparum malaria.

Question 61

What is the most common serious complication of P. falciparum malaria?\na) Cerebral malaria\nb) Pulmonary oedema\nc) Renal failure\nd) Algid malaria

Answer 61

Answer: a) Cerebral malaria\nExplanation: Cerebral malaria is a severe complication of P. falciparum infection, marked by coma, hyperpyrexia, and convulsions.

Question 62

Which of the following is a fatal complication of severe falciparum malaria often associated with over-administration of intravenous fluids?\na) Hypoglycemia\nb) Pulmonary oedema\nc) Blackwater fever\nd) Anaemia

Answer 62

Answer: b) Pulmonary oedema\nExplanation: Pulmonary oedema, often caused by excessive IV fluids, is a grave complication of severe P. falciparum malaria.

Question 63

What phase of the Plasmodium life cycle occurs in the mosquito?\na) Erythrocytic cycle\nb) Pre-erythrocytic cycle\nc) Sporozoite phase\nd) Extrinsic cycle

Answer 63

Answer: d) Extrinsic cycle\nExplanation: The extrinsic cycle takes place in the mosquito, where gametocytes develop into gametes, fertilize, and eventually form sporozoites.

Question 64

What stage of the Plasmodium life cycle infects liver cells in humans?\na) Gametocytes\nb) Sporozoites\nc) Merozoites\nd) Ookinete

Answer 64

Answer: b) Sporozoites\nExplanation: Sporozoites are injected into humans by mosquitoes and travel to the liver to infect hepatocytes.

Question 65

What condition is characterized by the lysis of red blood cells and the presence of free haemoglobin in the blood and urine?\na) Cerebral malaria\nb) Pulmonary oedema\nc) Blackwater fever\nd) Algid malaria

Answer 65

Answer: c) Blackwater fever\nExplanation: Blackwater fever is associated with P. falciparum malaria and results in massive erythrocyte destruction and dark-colored urine due to haemoglobinuria.

Question 66

Which of the following symptoms is common in algid malaria?\na) High blood pressure\nb) Cold, clammy skin\nc) Intense sweating\nd) Elevated glucose levels

Answer 66

Answer: b) Cold, clammy skin\nExplanation: Algid malaria is marked by circulatory collapse, cold skin, and low blood pressure due to shock.

Question 67

What is the main cause of death in blackwater fever?\na) Renal failure\nb) Cerebral hemorrhage\nc) Heart failure\nd) Pulmonary oedema

Answer 67

Answer: a) Renal failure\nExplanation: Renal failure due to impaired glomerular filtration and tubular resorption is often the cause of death in blackwater fever.

Question 68

Hypoglycemia in falciparum malaria is caused by which of the following?\na) Increased insulin production\nb) Reduced concentration of blood glucose\nc) Decreased liver function\nd) Hypermetabolism of the parasite

Answer 68

Answer: b) Reduced concentration of blood glucose\nExplanation: Hypoglycemia, or reduced blood glucose levels, is common in falciparum malaria due to the parasite’s metabolic demands.

Question 69

Why is the clinical diagnosis of malaria considered unreliable?\na) It requires advanced equipment\nb) Malaria symptoms are non-specific\nc) It is too expensive\nd) It only detects severe cases

Answer 69

Answer: b) Malaria symptoms are non-specific\nExplanation: The clinical diagnosis of malaria is unreliable due to the overlap of symptoms with other febrile illnesses.

Question 70

What is the ‘gold standard’ for malaria diagnosis?\na) Rapid diagnostic test\nb) Microscopy\nc) PCR test\nd) Serology

Answer 70

Answer: b) Microscopy\nExplanation: Microscopy remains the gold standard for malaria diagnosis, allowing for the identification and quantification of malaria parasites.

Question 71

Which diagnostic test detects Histidine-rich protein II (HRP-II)?\na) Microscopy\nb) PCR\nc) RDT for P. falciparum\nd) Blood smear

Answer 71

Answer: c) RDT for P. falciparum\nExplanation: Rapid diagnostic tests for P. falciparum detect HRP-II, a protein produced by the trophozoites of the parasite.

Question 72

Which antigen is detected by rapid diagnostic tests (RDTs) for all species of Plasmodium?\na) Aldolase\nb) HRP-II\nc) pLDH\nd) Gametocyte antigen

Answer 72

Answer: a) Aldolase\nExplanation: Aldolase is targeted by RDTs that detect a ‘pan-malarial’ antigen common to all Plasmodium species.

Question 73

What is a key disadvantage of microscopy for malaria diagnosis?\na) It is too specific\nb) It requires trained personnel\nc) It takes only 15 minutes\nd) It cannot identify species

Answer 73

Answer: b) It requires trained personnel\nExplanation: Microscopy is labor-intensive, time-consuming, and depends on well-trained technicians and good equipment.

Question 74

What advantage do RDTs have over microscopy in malaria diagnosis?\na) Faster results\nb) Higher specificity\nc) Requires less blood\nd) Can detect parasites at any stage

Answer 74

Answer: a) Faster results\nExplanation: RDTs are faster, providing results in about 15 minutes, whereas microscopy can take at least an hour.

Question 75

Which malaria-causing parasite is most likely to result in severe complications?\na) P. vivax\nb) P. falciparum\nc) P. malariae\nd) P. ovale

Answer 75

Answer: b) P. falciparum\nExplanation: P. falciparum is responsible for the majority of severe and fatal malaria cases, especially due to complications like cerebral malaria.

Question 76

Which type of malaria is more likely to present with gastrointestinal symptoms and headache?\na) P. vivax\nb) P. malariae\nc) P. falciparum\nd) P. ovale

Answer 76

Answer: c) P. falciparum\nExplanation: P. falciparum malaria often presents with gastrointestinal symptoms like nausea and vomiting, as well as headaches, which can become severe.

Question 77

In the human host, which cells are initially infected by Plasmodium sporozoites?\na) Red blood cells\nb) White blood cells\nc) Liver cells\nd) Spleen cells

Answer 77

Answer: c) Liver cells\nExplanation: After being injected by the mosquito, sporozoites travel to and infect liver cells, where they mature into merozoites.

Question 78

What stage of Plasmodium is released from ruptured red blood cells to infect other red cells?\na) Gametocytes\nb) Ookinetes\nc) Sporozoites\nd) Merozoites

Answer 78

Answer: d) Merozoites\nExplanation: Merozoites are released when infected red blood cells rupture and then invade new red blood cells to continue the infection cycle.

Question 79

Which type of malaria is associated with nephrotic syndrome in chronic cases?\na) P. vivax\nb) P. falciparum\nc) P. malariae\nd) P. ovale

Answer 79

Answer: c) P. malariae\nExplanation: Chronic infection with P. malariae is commonly linked to nephrotic syndrome, characterized by heavy proteinuria (nephrosis).

Question 80

What is the estimated duration of a typical paroxysm in tertian malaria (P. vivax)?\na) 6 hours\nb) 8 hours\nc) 10 hours\nd) 12 hours

Answer 80

Answer: c) 10 hours\nExplanation: In P. vivax malaria, the paroxysm (cycle of fever, chills, and sweating) typically lasts around 10 hours.

Question 81

“What type of malaria is characterized by continuous or remittent fever, as opposed to intermittent fever?\na) P. vivax\nb) P. malariae\nc) P. falciparum\nd) P. o

Question 82

Question and Options

Answer 82

Answer and Explanation

Question 83

In quartan malaria (P. malariae), how frequently do the attacks occur? a) Every 24 hours b) Every 48 hours c) Every 72 hours d) Every 96 hours

Answer 83

Answer: c) Every 72 hours; Explanation: In quartan malaria, caused by P. malariae, the attacks occur every 72 hours if only a single brood of parasites is present.

Question 84

What is a common complication of any type of malaria? a) Anaemia b) Pulmonary oedema c) Hypoglycemia d) Blackwater fever

Answer 84

Answer: a) Anaemia; Explanation: Anaemia is a frequent complication of all types of malaria due to the destruction of red blood cells by the parasite.

Question 85

Which type of malaria is associated with splenic rupture? a) P. falciparum b) P. malariae c) P. vivax d) P. ovale

Answer 85

The correct answer is a) P. falciparum.

Why:

Plasmodium falciparum is the most dangerous species of the malaria parasite, and it is strongly associated with severe complications, including splenic rupture. This occurs because:

P. falciparum causes high levels of parasitemia (high numbers of parasites in the blood), which can lead to the enlargement and rupture of the spleen. The spleen becomes congested due to the accumulation of infected red blood cells, making it more prone to rupture, especially in severe cases of malaria.

The rupture of the spleen is a potentially life-threatening condition that requires immediate medical attention.

While P. vivax, P. ovale, and P. malariae can also cause splenomegaly (enlarged spleen), splenic rupture is more commonly associated with P. falciparum due to its more severe and acute impact on the body.

Question 86

Nephrosis, characterized by large amounts of albumin in the urine, is commonly associated with which type of malaria? a) P. falciparum b) P. malariae c) P. vivax d) P. ovale

Answer 86

Answer: b) P. malariae; Explanation: Chronic P. malariae infection is often linked to nephrosis, leading to proteinuria (albumin in the urine).

Question 87

What symptom is more pronounced in P. falciparum malaria compared to other types of malaria? a) Prostration b) Fever paroxysms c) Sweating d) Joint pain

Answer 87

Answer: a) Prostration; Explanation: Prostration and a greater tendency to delirium are more pronounced in P. falciparum malaria.

Question 88

What is the most common serious complication of P. falciparum malaria? a) Cerebral malaria b) Pulmonary oedema c) Renal failure d) Algid malaria

Answer 88

Answer: a) Cerebral malaria; Explanation: Cerebral malaria is a severe complication of P. falciparum infection, marked by coma, hyperpyrexia, and convulsions.

Question 89

Which of the following is a fatal complication of severe falciparum malaria often associated with over-administration of intravenous fluids? a) Hypoglycemia b) Pulmonary oedema c) Blackwater fever d) Anaemia

Answer 89

Answer: b) Pulmonary oedema; Explanation: Pulmonary oedema, often caused by excessive IV fluids, is a grave complication of severe P. falciparum malaria.

Question 90

What phase of the Plasmodium life cycle occurs in the mosquito? a) Erythrocytic cycle b) Pre-erythrocytic cycle c) Sporozoite phase d) Extrinsic cycle

Answer 90

Answer: d) Extrinsic cycle; Explanation: The extrinsic cycle takes place in the mosquito, where gametocytes develop into gametes, fertilize, and eventually form sporozoites.

Question 91

What stage of the Plasmodium life cycle infects liver cells in humans? a) Gametocytes b) Sporozoites c) Merozoites d) Ookinete

Answer 91

Answer: b) Sporozoites; Explanation: Sporozoites are injected into humans by mosquitoes and travel to the liver to infect hepatocytes.

Question 92

What condition is characterized by the lysis of red blood cells and the presence of free haemoglobin in the blood and urine? a) Cerebral malaria b) Pulmonary oedema c) Blackwater fever d) Algid malaria

Answer 92

Answer: c) Blackwater fever; Explanation: Blackwater fever is associated with P. falciparum malaria and results in massive erythrocyte destruction and dark-colored urine due to haemoglobinuria.

Question 93

Which of the following symptoms is common in algid malaria? a) High blood pressure b) Cold, clammy skin c) Intense sweating d) Elevated glucose levels

Answer 93

Answer: b) Cold, clammy skin; Explanation: Algid malaria is marked by circulatory collapse, cold skin, and low blood pressure due to shock.

Question 94

What is the main cause of death in blackwater fever? a) Renal failure b) Cerebral hemorrhage c) Heart failure d) Pulmonary oedema

Answer 94

Answer: a) Renal failure; Explanation: Renal failure due to impaired glomerular filtration and tubular resorption is often the cause of death in blackwater fever.

Question 95

Hypoglycemia in falciparum malaria is caused by which of the following? a) Increased insulin production b) Reduced concentration of blood glucose c) Decreased liver function d) Hypermetabolism of the parasite

Answer 95

Answer: b) Reduced concentration of blood glucose; Explanation: Hypoglycemia, or reduced blood glucose levels, is common in falciparum malaria due to the parasite’s metabolic demands.

Question 96

Why is the clinical diagnosis of malaria considered unreliable? a) It requires advanced equipment b) Malaria symptoms are non-specific c) It is too expensive d) It only detects severe cases

Answer 96

Answer: b) Malaria symptoms are non-specific; Explanation: The clinical diagnosis of malaria is unreliable due to the overlap of symptoms with other febrile illnesses.

Question 97

What is the “gold standard” for malaria diagnosis? a) Rapid diagnostic test b) Microscopy c) PCR test d) Serology

Answer 97

Answer: b) Microscopy; Explanation: Microscopy remains the gold standard for malaria diagnosis, allowing for the identification and quantification of malaria parasites.

Question 98

Which diagnostic test detects Histidine-rich protein II (HRP-II)? a) Microscopy b) PCR c) RDT for P. falciparum d) Blood smear

Answer 98

Answer: c) RDT for P. falciparum; Explanation: Rapid diagnostic tests for P. falciparum detect HRP-II, a protein produced by the trophozoites of the parasite.

Question 99

Which antigen is detected by rapid diagnostic tests (RDTs) for all species of Plasmodium? a) Aldolase b) HRP-II c) pLDH d) Gametocyte antigen

Answer 99

Answer: a) Aldolase; Explanation: Aldolase is targeted by RDTs that detect a “pan-malarial” antigen common to all Plasmodium species.

Question 100

What is a key disadvantage of microscopy for malaria diagnosis? a) It is too specific b) It requires trained personnel c) It takes only 15 minutes d) It cannot identify species

Answer 100

Answer: b) It requires trained personnel; Explanation: Microscopy is labor-intensive, time-consuming, and depends on well-trained technicians and good equipment.

Question 101

What advantage do RDTs have over microscopy in malaria diagnosis? a) Faster results b) Higher specificity c) Requires less blood d) Can detect parasites at any stage

Answer 101

Answer: a) Faster results; Explanation: RDTs are faster, providing results in about 15 minutes, whereas microscopy can take at least an hour.

Question 102

Which malaria-causing parasite is most likely to result in severe complications? a) P. vivax b) P. falciparum c) P. malariae d) P. ovale

Answer 102

Answer: b) P. falciparum; Explanation: P. falciparum is responsible for the majority of severe and fatal malaria cases, especially due to complications like cerebral malaria.

Question 103

Which type of malaria is more likely to present with gastrointestinal symptoms and headache? a) P. vivax b) P. malariae c) P. falciparum d) P. ovale

Answer 103

Answer: c) P. falciparum; Explanation: P. falciparum malaria often presents with gastrointestinal symptoms like nausea and vomiting, as well as headaches, which can become severe.

Question 104

In the human host, which cells are initially infected by Plasmodium sporozoites? a) Red blood cells b) White blood cells c) Liver cells d) Spleen cells

Answer 104

Answer: c) Liver cells; Explanation: After being injected by the mosquito, sporozoites travel to and infect liver cells, where they mature into merozoites.

Question 105

What stage of Plasmodium is released from ruptured red blood cells to infect other red cells? a) Gametocytes b) Ookinetes c) Sporozoites d) Merozoites

Answer 105

Answer: d) Merozoites; Explanation: Merozoites are released when infected red blood cells rupture and then invade new red blood cells to continue the infection cycle.

Question 106

Which type of malaria is associated with nephrotic syndrome in chronic cases? a) P. vivax b) P. falciparum c) P. malariae d) P. ovale

Answer 106

Answer: c) P. malariae; Explanation: Chronic infection with P. malariae is commonly linked to nephrotic syndrome, characterized by heavy proteinuria (nephrosis).

Question 107

What is the estimated duration of a typical paroxysm in tertian malaria (P. vivax)? a) 6 hours b) 8 hours c) 10 hours d) 12 hours

Answer 107

Answer: c) 10 hours; Explanation: In P. vivax malaria, the paroxysm (cycle of fever, chills, and sweating) typically lasts around 10 hours.

Question 108

What type of malaria is characterized by continuous or remittent fever, as opposed to intermittent fever? a) P. vivax b) P. malariae c) P. falciparum d) P. ovale

Answer 108

Answer: c) P. falciparum; Explanation: P. falciparum malaria is often associated with continuous or remittent fever rather than the classic intermittent fever seen in other forms.

Question 109

What diagnostic method is considered the most reliable for determining parasitemia levels in malaria? a) PCR b) Serology c) RDT d) Microscopy

Answer 109

“Answer: d)

Question 110

Question and Options

Answer 110

Answer and Explanation

Question 111

Which of the following is NOT an individual control measure for malaria prevention? a) Chemoprophylaxis b) Use of insect repellents c) Use of larvicides d) Use of insecticide-impregnated nets and clothing

Answer 111

Answer: c Explanation: Individual control measures include chemoprophylaxis, insect repellents, and insecticide-impregnated nets/clothing. Larvicides are used for vector control, which is a communal measure.

Question 112

Why is malaria more severe in pregnant women compared to non-pregnant women? a) Increased susceptibility to mosquito bites b) Higher risk of transmission through placental blood c) Higher malaria-associated mortality d) Lack of immunity due to pregnancy

Answer 112

Answer: c Explanation: Malaria is more severe in pregnant women due to higher mortality rates, and it can cause complications such as abortion, stillbirth, and premature delivery.

Question 113

What is the significance of residual indoor spraying in malaria control? a) It prevents mosquitoes from laying eggs b) It selectively kills vectors that rest indoors c) It eliminates all mosquitoes within the community d) It creates a barrier against mosquito bites

Answer 113

Answer: b Explanation: Residual indoor spraying kills vectors that rest indoors, reducing transmission. However, its effectiveness can be limited by factors such as exophily and insufficient coverage.

Question 114

Which of the following correctly defines ‘Anthropophily’? a) Preference for biting indoors b) Preference for resting outdoors c) Preference for human blood d) Preference for animal blood

Answer 114

Answer: c Explanation: Anthropophily refers to a mosquito’s preference for human blood, which is critical in understanding vector control strategies.

Question 115

In Toxoplasma gondii, which stage is responsible for initiating the enteroepithelial cycle in cats? a) Tachyzoites b) Bradyzoites c) Sporozoites d) Merozoites

Answer 115

Answer: c Explanation: Sporozoites enter the epithelial cells in the small intestine of cats and initiate the enteroepithelial cycle.

Question 116

Which of the following is TRUE about the asexual reproduction of Toxoplasma gondii? a) It occurs only in cats b) It occurs through a process known as schizogony c) It is known as endodyogeny d) It only happens in the blood

Answer 116

Answer: c Explanation: Asexual reproduction in Toxoplasma gondii occurs via endodyogeny, where two daughter cells form inside a mother cell.

Question 117

How can humans acquire Toxoplasma gondii infection? a) Inhalation of spores b) Direct ingestion of oocysts from cat feces c) Bite of infected mosquitoes d) Transfusion of infected blood

Answer 117

Answer: b Explanation: Humans can acquire toxoplasmosis by ingesting oocysts from cat feces or bradyzoites from undercooked meat.

Question 118

What is the primary target organ in cases of congenital toxoplasmosis? a) Liver b) Brain c) Lungs d) Kidneys

Answer 118

Answer: b Explanation: In congenital toxoplasmosis, the brain is often the primary target, leading to potential malformations such as hydrocephaly and mental retardation.

Question 119

Which antimalarial drug is NOT commonly used for prophylaxis? a) Chloroquine b) Proguanil c) Artemether-lumefantrine d) Doxycycline

Answer 119

Answer: c Explanation: Artemether-lumefantrine is typically used for treatment, not prophylaxis. Drugs like chloroquine, proguanil, and doxycycline are used for malaria prophylaxis.

Question 120

Which of the following is a symptom of chronic toxoplasmosis? a) Painful, swollen lymph nodes b) Rupture of cysts in the brain c) Acute encephalitis d) Fever and muscle pain

Answer 120

Answer: b Explanation: Chronic toxoplasmosis involves the formation of tissue cysts, and if they rupture in the brain, it can cause chronic encephalitis.

Question 121

Question and Options

Answer 121

Answer and Explanation

Question 122

11. What is the role of endophily in vector control? a) It encourages vectors to bite indoors b) It allows vectors to rest indoors, making them vulnerable to insecticide c) It ensures vectors avoid indoor spraying d) It allows vectors to breed in water bodies indoors

Answer 122

Answer: b Explanation: Endophily refers to vectors resting indoors, where they can be targeted by indoor residual spraying.

Question 123

12. What is the term used for vectors that prefer animal blood? a) Anthropophily b) Zoophily c) Endophily d) Exophily

Answer 123

Answer: b Explanation: Zoophily refers to vectors that prefer animal blood, which affects vector control strategies.

Question 124

13. Which stage of Toxoplasma gondii is responsible for rapid multiplication during the acute phase? a) Tachyzoites b) Bradyzoites c) Sporozoites d) Oocysts

Answer 124

Answer: a Explanation: Tachyzoites multiply rapidly during the acute phase of toxoplasmosis, spreading through the host’s body.

Question 125

14. In what condition does toxoplasmosis become subacute? a) When immunity develops too rapidly b) When tachyzoites are cleared quickly c) When immunity develops slowly d) When bradyzoites form early in infection

Answer 125

Answer: c Explanation: Subacute toxoplasmosis occurs when immunity develops slowly, allowing tachyzoites to continue destroying cells.

Question 126

15. Which symptom is commonly associated with acute toxoplasmosis in humans? a) Blindness b) Paralysis c) Swollen lymph nodes d) Myocarditis

Answer 126

Answer: c Explanation: Swollen lymph nodes, often in the cervical region, are a common symptom of acute toxoplasmosis.

Question 127

16. What is the primary consequence of repeated retinal infection in chronic toxoplasmosis? a) Myocarditis b) Blindness c) Pneumonia d) Paralysis

Answer 127

Answer: b Explanation: Repeated retinal infections in chronic toxoplasmosis can lead to blindness due to damage and rupture of cysts.

Question 128

17. Which factor does NOT contribute to the severity of toxoplasmosis? a) Age of the host b) Virulence of Toxoplasma strain c) Vector control strategies d) Natural susceptibility of the host

Answer 128

Answer: c Explanation: Vector control strategies are not relevant to the severity of toxoplasmosis, which is influenced by host factors and the parasite’s virulence.

Question 129

18. What is the recommended control measure for malaria in urban areas with few breeding sites? a) Residual indoor spraying b) Larval control c) Use of chemoprophylaxis d) Zoophilic vector control

Answer 129

Answer: b Explanation: Larval control is recommended in densely populated areas with limited breeding sites, such as urban environments.

Question 130

19. Which of the following is true about congenital toxoplasmosis? a) It is always symptomatic b) It can result in severe malformations c) It is not transmitted transplacentally d) It primarily affects the lungs

Answer 130

Answer: b Explanation: Congenital toxoplasmosis can result in severe malformations, such as hydrocephaly and microcephaly, although it is often asymptomatic.

Question 131

20. What is the most common mode of human infection with Toxoplasma gondii? a) Contact with infected mosquitoes b) Ingestion of undercooked meat c) Direct inhalation of bradyzoites d) Skin penetration of sporozoites

Answer 131

Answer: b Explanation: Humans most commonly acquire toxoplasmosis by ingesting undercooked meat containing bradyzoites.

Question 132

21. Which antimalarial drug is commonly used in areas where chloroquine resistance is present? a) Chloroquine b) Proguanil c) Doxycycline d) Quinine

Answer 132

Answer: c Explanation: Doxycycline is commonly used in areas with chloroquine-resistant strains of malaria, offering an alternative for prophylaxis and treatment.

Question 133

22. Which control measure directly targets mosquito larvae? a) Indoor residual spraying b) Use of insect repellents c) Larvicides d) Bed nets

Answer 133

Answer: c Explanation: Larvicides target mosquito larvae in breeding sites, helping reduce the population before they mature into adults.

Question 134

23. How do rapid diagnostic tests (RDTs) for malaria work? a) They detect antibodies produced by the host b) They detect circulating antigens of the parasite c) They measure the number of infected red blood cells d) They detect the parasite’s DNA directly

Answer 134

Answer: b Explanation: RDTs detect circulating antigens of the parasite, making them effective even when parasites are sequestered in deeper tissues and undetectable by microscopy.

Question 135

24. Which of the following vectors is responsible for malaria transmission? a) Anopheles mosquitoes b) Aedes mosquitoes c) Culex mosquitoes d) Sandflies

Answer 135

Answer: a Explanation: Anopheles mosquitoes are the vectors responsible for transmitting the malaria parasite (Plasmodium spp.).

Question 136

25. Which of the following is a classical larvicide? a) DDT b) Paris green c) Pyrethroids d) Permethrin

Answer 136

Answer: b Explanation: Paris green is a classical larvicide used to control mosquito larvae in breeding sites, such as stagnant water.

Question 137

26. What is the principal site of multiplication for Toxoplasma gondii in humans? a) Lymph nodes b) Intestinal epithelial cells c) Red blood cells d) Liver and lungs

Answer 137

Answer: d Explanation: The liver and lungs are the primary sites of multiplication for Toxoplasma gondii during the acute phase of infection.

Question 138

27. Which of the following best describes endophagy? a) The tendency of mosquitoes to bite indoors b) The tendency of mosquitoes to rest outdoors c) The tendency of mosquitoes to bite animals d) The tendency of mosquitoes to rest indoors

Answer 138

Answer: a Explanation: Endophagy refers to mosquitoes’ tendency to bite indoors, which is a critical factor in determining the effectiveness of indoor vector control methods.

Question 139

28. Which of the following is associated with subacute toxoplasmosis? a) Rapid tachyzoite proliferation b) Development of extensive lesions in vital organs c) Formation of cysts in the retina d) Asymptomatic infection

Answer 139

Answer: b Explanation: In subacute toxoplasmosis, tachyzoites continue to destroy cells, leading to the development of extensive lesions in organs like the lungs, heart, and brain.

Question 140

29. Which type of mosquito is most likely to rest outdoors after feeding? a) Endophilic mosquitoes b) Exophilic mosquitoes c) Zoophilic mosquitoes d) Anthropophilic mosquitoes

Answer 140

Answer: b Explanation: Exophilic mosquitoes prefer to rest outdoors after feeding, which can make them harder to target with indoor residual spraying.

Question 141

30. What is the primary source of infection for humans in cases of toxoplasmosis? a) Infected water sources b) Direct contact with cat urine c) Consumption of undercooked meat or exposure to cat feces d) Airborne transmission from infected individuals

Answer 141

Answer: c Explanation: Humans primarily acquire toxoplasmosis by consuming undercooked meat containing tissue cysts or by ingesting oocysts from contaminated cat feces.

Question 142

31. What occurs during the enteroepithelial cycle of Toxoplasma gondii in cats? a) Formation of bradyzoites b) Sexual reproduction c) Development of tachyzoites d) Asexual reproduction by endodyogeny

Answer 142

Answer: b Explanation: The enteroepithelial cycle in cats involves sexual reproduction, with the formation of gametocytes and the release of oocysts in the cat’s feces.

Question 143

32. Which of the following best describes ‘Exophily’? a) The tendency of mosquitoes to feed indoors b) The tendency of mosquitoes to rest outdoors c) The preference of mosquitoes for animal blood d) The preference of mosquitoes for human blood

Answer 143

Answer: b Explanation: Exophily refers to the tendency of mosquitoes to rest outdoors after feeding, making them less susceptible to indoor residual spraying.

Question 144

33. How do bradyzoites contribute to chronic toxoplasmosis? a) They are rapidly dividing forms in acute infections b) They form cysts in muscles and the brain c) They stimulate immediate immune responses d) They cause severe symptoms of acute disease

Answer 144

Answer: b Explanation: Bradyzoites are the slow-dividing form of Toxoplasma gondii, and they accumulate in tissue cysts in muscles and the brain during chronic infection.

Question 145

34. What is the primary method of diagnosing toxoplasmosis in immunocompromised patients? a) Detection of antibodies b) Detection of circulating antigens c) Detection of tachyzoites in the blood d) Detection of bradyzoites in muscle biopsies

Answer 145

Answer: a Explanation: In immunocompromised patients, toxoplasmosis is commonly diagnosed through the detection of antibodies against Toxoplasma gondii, indicating prior exposure or active infection.

Question 146

35. Which of the following drugs is NOT effective against Toxoplasma gondii? a) Sulfadoxine-pyrimethamine b) Doxycycline c) Atovaquone d) Spiramycin

Answer 146

Answer: b Explanation: Doxycycline is primarily used for malaria prophylaxis, while drugs like sulfadoxine-pyrimethamine, atovaquone, and spiramycin are used for treating toxoplasmosis.

Question 147

36. What is the primary pathological site in acute toxoplasmosis in cats? a) Central nervous system b) Lungs c) Intestinal epithelium d) Liver

Answer 147

Answer: c Explanation: In cats, acute toxoplasmosis primarily affects the intestinal epithelium, where the parasite undergoes its enteroepithelial cycle.

Question 148

“37. What are the characteristics of congenital toxoplasmosis? a) It is always symptomatic b) It frequently results in stillbirths and severe

Question 149

Question and Options

Answer 149

Answer and Explanation

Question 150

37. What are the characteristics of congenital toxoplasmosis? a) It is always symptomatic b) It frequently results in stillbirths and severe malformations c) It is easily treated with standard antimalarials d) It does not affect the newborn’s vision

Answer 150

Answer: b Explanation: Congenital toxoplasmosis can lead to stillbirths and severe malformations, though many cases are asymptomatic at birth.

Question 151

38. Which of the following factors can exacerbate the severity of toxoplasmosis in immunocompromised individuals? a) Active immune response b) High levels of bradyzoites c) Co-infection with other pathogens d) Strong genetic resistance

Answer 151

Answer: c Explanation: Co-infection with other pathogens can exacerbate the severity of toxoplasmosis in immunocompromised individuals, leading to more severe clinical outcomes.

Question 152

39. What is a common treatment option for severe cases of toxoplasmosis in immunocompromised patients? a) Quinine b) Spiramycin c) Clindamycin d) Metronidazole

Answer 152

Answer: c Explanation: Clindamycin is commonly used in severe cases of toxoplasmosis, especially in immunocompromised patients, in combination with other treatments.

Question 153

40. Which insecticide is commonly used for indoor residual spraying (IRS) in malaria vector control? a) DDT b) Pyrethroids c) Organophosphates d) Carbamates

Answer 153

Answer: b Explanation: Pyrethroids are commonly used for indoor residual spraying in malaria vector control due to their effectiveness and relatively low toxicity.

Question 154

41. What is the role of bed nets in malaria prevention? a) They repel mosquitoes b) They provide a physical barrier to prevent bites c) They kill mosquitoes on contact d) They enhance indoor residual spraying

Answer 154

Answer: b Explanation: Bed nets provide a physical barrier to prevent mosquito bites, particularly when treated with insecticides, increasing their efficacy.

Question 155

42. Which of the following best describes the term ‘zoophilic’? a) Preferentially feeding on human blood b) Preferentially resting indoors c) Preferentially feeding on animal blood d) Preferring to breed indoors

Answer 155

Answer: c Explanation: Zoophilic refers to vectors, such as some mosquito species, that preferentially feed on animal blood rather than human blood.

Question 156

43. What is a significant risk factor for the transmission of congenital toxoplasmosis? a) High consumption of fish b) Inadequate cooking of pork c) High exposure to outdoor cats d) Ingesting unpasteurized dairy products

Answer 156

Answer: c Explanation: High exposure to outdoor cats increases the risk of congenital toxoplasmosis due to potential ingestion of oocysts shed in cat feces.

Question 157

44. How does Toxoplasma gondii evade the host’s immune response? a) By rapidly multiplying in the blood b) By forming cysts in tissues c) By causing immediate symptoms d) By stimulating high levels of antibodies

Answer 157

Answer: b Explanation: Toxoplasma gondii evades the host’s immune response by forming cysts in tissues, where it can remain dormant and undetected.

Question 158

45. Which type of malaria is characterized by severe anemia? a) Plasmodium falciparum b) Plasmodium vivax c) Plasmodium malariae d) Plasmodium ovale

Answer 158

Answer: a Explanation: Plasmodium falciparum is associated with severe anemia due to the high rate of red blood cell destruction and sequestration.

Question 159

46. Which of the following is a method of vector control that uses biological agents? a) Indoor residual spraying b) Larviciding c) Use of insect growth regulators d) Release of genetically modified mosquitoes

Answer 159

Answer: d Explanation: The release of genetically modified mosquitoes is a biological vector control method aimed at reducing the population of disease-carrying mosquitoes.

Question 160

47. What is the primary vector for chikungunya? a) Anopheles mosquitoes b) Culex mosquitoes c) Aedes mosquitoes d) Tabanidae flies

Answer 160

Answer: c Explanation: Aedes mosquitoes, particularly Aedes aegypti and Aedes albopictus, are the primary vectors for chikungunya virus transmission.

Question 161

48. Which symptoms are typically associated with acute chikungunya infection? a) Fever and rash b) Nausea and vomiting c) Diarrhea and abdominal pain d) Severe respiratory distress

Answer 161

Answer: a Explanation: Acute chikungunya infection typically presents with fever and rash, along with severe joint pain.

Question 162

49. What is the main goal of malaria elimination programs? a) To reduce the incidence of malaria b) To eradicate all malaria cases globally c) To control vector populations d) To eliminate Plasmodium from human hosts

Answer 162

Answer: a Explanation: The main goal of malaria elimination programs is to reduce the incidence of malaria to zero in a specific region.

Question 163

50. Which of the following factors contributes to the re-emergence of malaria in previously controlled areas? a) Increased use of bed nets b) Drug resistance c) Enhanced surveillance systems d) Improved sanitation

Answer 163

Answer: b Explanation: Drug resistance in malaria parasites can contribute to the re-emergence of malaria in areas where it was previously controlled.

Question 164

51. What is the primary function of insect repellents in malaria prevention? a) Killing adult mosquitoes b) Deterring mosquitoes from biting c) Preventing larvae from developing d) Enhancing indoor spraying effectiveness

Answer 164

Answer: b Explanation: Insect repellents work by deterring mosquitoes from biting, thus reducing the risk of malaria transmission.

Question 165

52. Which disease is primarily transmitted through the Aedes aegypti mosquito? a) Malaria b) Yellow fever c) Schistosomiasis d) Leptospirosis

Answer 165

Answer: b Explanation: Yellow fever is primarily transmitted through the bite of infected Aedes aegypti mosquitoes.

Question 166

53. How does the immune response to Toxoplasma gondii differ in immunocompetent versus immunocompromised individuals? a) Immunocompetent individuals show stronger responses b) There is no difference in response c) Immunocompromised individuals show stronger responses d) Both groups respond similarly

Answer 166

Answer: a Explanation: Immunocompetent individuals typically mount a stronger immune response to Toxoplasma gondii than immunocompromised individuals, who may experience severe disease.

Question 167

54. Which antimalarial drug is used as a first-line treatment for uncomplicated malaria? a) Quinine b) Chloroquine c) Doxycycline d) Artemisinin

Answer 167

Answer: b Explanation: Chloroquine is commonly used as a first-line treatment for uncomplicated malaria caused by Plasmodium vivax and Plasmodium ovale.

Question 168

55. Which of the following is a primary symptom of severe malaria? a) Fatigue b) Anemia c) Neurological impairment d) All of the above

Answer 168

Answer: d Explanation: All of the above symptoms can occur in severe malaria, highlighting the serious nature of the disease.

Question 169

56. Which type of immunity is primarily involved in combating Toxoplasma gondii infections? a) Humoral immunity b) Innate immunity c) Cell-mediated immunity d) Passive immunity

Answer 169

Answer: c Explanation: Cell-mediated immunity plays a crucial role in combating Toxoplasma gondii infections by activating T cells to control tachyzoite proliferation.

Question 170

57. What is the mode of action for artemisinin-based combination therapies (ACTs)? a) They inhibit DNA synthesis b) They disrupt protein synthesis c) They kill parasites by generating reactive oxygen species d) They block glycolysis in parasites

Answer 170

Answer: c Explanation: Artemisinin-based combination therapies (ACTs) kill parasites by generating reactive oxygen species, leading to parasite death.

Question 171

58. Which intervention is most effective in reducing malaria transmission in high-risk areas? a) Only using insecticide-treated nets b) Community-wide insecticide spraying c) Providing treatment for malaria d) Integrating multiple strategies, including education and vector control

Answer 171

Answer: d Explanation: Integrating multiple strategies, including education, vector control, and treatment, is most effective in reducing malaria transmission in high-risk areas.

Question 172

59. What is the significance of diagnosing malaria promptly? a) It allows for immediate treatment b) It prevents outbreaks c) It helps monitor drug resistance d) All of the above

Answer 172

Answer: d Explanation: Prompt diagnosis of malaria is significant as it allows for immediate treatment, helps prevent outbreaks, and aids in monitoring drug resistance.

Question 173

60. Which of the following strategies can be implemented for effective vector control in urban areas? a) Use of larvicides b) Environmental management c) Community engagement d) All of the above

Answer 173

Answer: d Explanation: Effective vector control in urban areas can be achieved through a combination of strategies, including larvicides, environmental management, and community engagement.

Question 174

Question

Answer 174

Answer and Explanation

Question 175

1. Which of the following is the most suitable medium for culturing Toxoplasma gondii?\na) Guinea pigs\nb) Mice\nc) Hamsters\nd) Rabbits

Answer 175

Answer: b\nExplanation: Mice are the most suitable medium for culturing Toxoplasma gondii as they do not suffer from toxoplasmosis and provide a conducive environment for the parasite.

Question 176

2. The most widely used serological test for detecting antibodies to Toxoplasma gondii is:\na) Direct agglutination test\nb) Fluorescent antibody test\nc) Sabin-Feldman dye test\nd) Complement fixation test

Answer 176

Answer: c\nExplanation: The Sabin-Feldman dye test is a highly sensitive and widely used serological test for detecting antibodies to Toxoplasma gondii.

Question 177

3. Which of the following is NOT commonly used for diagnosing toxoplasmosis?\na) PCR for T. gondii DNA\nb) Urine analysis\nc) Serological tests\nd) Microscopic examination of tissue samples

Answer 177

Answer: b\nExplanation: Urine analysis is not used for diagnosing toxoplasmosis, while serology, PCR, and tissue examination are standard diagnostic methods.

Question 178

4. The most effective combination of drugs for treating toxoplasmosis in humans is:\na) Penicillin and sulfonamides\nb) Pyrimethamine and sulfonamides\nc) Metronidazole and pyrimethamine\nd) Quinine and metronidazole

Answer 178

Answer: b\nExplanation: The combination of pyrimethamine and sulfonamides is considered the most effective treatment for toxoplasmosis in humans and animals.

Question 179

5. Which of the following vectors is responsible for transmitting Leishmania parasites?\na) Aedes mosquitoes\nb) Phlebotomine sandflies\nc) Culex mosquitoes\nd) Tsetse flies

Answer 179

Answer: b\nExplanation: Phlebotomine sandflies are the only known vectors responsible for transmitting Leishmania parasites.

Question 180

6. Cutaneous leishmaniasis typically presents as:\na) Enlarged spleen and liver\nb) Ulcers or nodules on the skin\nc) Destruction of nasal mucosa\nd) Fever and anemia

Answer 180

Answer: b\nExplanation: Cutaneous leishmaniasis generally presents with ulcers or nodules on the skin due to the infection of dermal macrophages by Leishmania parasites.

Question 181

7. In which form of leishmaniasis do destructive ulcerations of the mucosa occur?\na) Cutaneous leishmaniasis\nb) Visceral leishmaniasis\nc) Muco-cutaneous leishmaniasis\nd) Post-kala-azar dermal leishmaniasis

Answer 181

Answer: c\nExplanation: Muco-cutaneous leishmaniasis is characterized by progressively destructive ulcerations of the mucosa, particularly affecting the nose and mouth.

Question 182

8. Which of the following is NOT a clinical form of leishmaniasis?\na) Cutaneous leishmaniasis\nb) Muco-cutaneous leishmaniasis\nc) Visceral leishmaniasis\nd) Dermal leishmaniasis

Answer 182

Answer: d\nExplanation: Dermal leishmaniasis is not a recognized clinical form. The main forms are cutaneous, muco-cutaneous, visceral, and post-kala-azar dermal leishmaniasis.

Question 183

9. Visceral leishmaniasis is also known as:\na) Kala-azar\nb) Espundia\nc) Dermal leishmaniasis\nd) Splenomegaly fever

Answer 183

Answer: a\nExplanation: Visceral leishmaniasis is also known as kala-azar, and it is characterized by long-duration fever, splenomegaly, and anemia.

Question 184

10. Post-kala-azar dermal leishmaniasis is frequently observed after treatment in:\na) Brazil\nb) Sudan\nc) India\nd) Spain

Answer 184

Answer: b\nExplanation: Post-kala-azar dermal leishmaniasis is a complication often observed after treatment for visceral leishmaniasis, especially in Sudan.

Question 185

11. Leishmania donovani primarily affects which system in the human body?\na) Cardiovascular system\nb) Respiratory system\nc) Reticuloendothelial system\nd) Digestive system

Answer 185

Answer: c\nExplanation: Leishmania donovani primarily affects the reticuloendothelial system, particularly the spleen, liver, and bone marrow.

Question 186

12. What is a key difference between zoonotic and anthroponotic visceral leishmaniasis?\na) Zoonotic involves only humans as reservoirs\nb) Anthroponotic involves animals as reservoirs\nc) Zoonotic is transmitted from animals to humans\nd) Anthroponotic occurs in non-feline animals

Answer 186

Answer: c\nExplanation: Zoonotic visceral leishmaniasis is transmitted from animals (mainly dogs) to humans, while anthroponotic visceral leishmaniasis is transmitted between humans via sandflies.

Question 187

13. Which of the following is a common vector of visceral leishmaniasis in East Africa?\na) Phlebotomus argentipes\nb) Phlebotomus martini\nc) Phlebotomus chinensis\nd) Lutzomyia longipalpis

Answer 187

Answer: b\nExplanation: Phlebotomus martini is a common vector of visceral leishmaniasis in East Africa.

Question 188

14. The life cycle of Leishmania donovani involves which two main forms?\na) Tachyzoites and bradyzoites\nb) Promastigotes and amastigotes\nc) Sporozoites and merozoites\nd) Oocysts and trophozoites

Answer 188

Answer: b\nExplanation: Leishmania donovani has two main forms: the promastigote form, found in the sandfly, and the amastigote form, which is intracellular in the human host.

Question 189

15. Which organ is most commonly enlarged in visceral leishmaniasis?\na) Lungs\nb) Kidneys\nc) Spleen\nd) Heart

Answer 189

Answer: c\nExplanation: Visceral leishmaniasis commonly results in the enlargement of the spleen (splenomegaly) due to the infection of macrophages within the reticuloendothelial system.

Question 190

16. Which of the following species causes zoonotic visceral leishmaniasis in the Mediterranean region?\na) Leishmania donovani\nb) Leishmania infantum\nc) Leishmania braziliensis\nd) Leishmania tropica

Answer 190

Answer: b\nExplanation: Leishmania infantum is responsible for zoonotic visceral leishmaniasis in the Mediterranean region, where dogs act as the primary reservoir.

Question 191

17. The transmission of Leishmania parasites to humans occurs through:\na) Contaminated water\nb) Infected blood transfusions\nc) Sandfly bites\nd) Direct contact with infected animals

Answer 191

Answer: c\nExplanation: Leishmania parasites are transmitted to humans through the bites of infected phlebotomine sandflies.

Question 192

18. Which species of sandfly is the main vector of kala-azar in India?\na) Phlebotomus pernicious\nb) Phlebotomus papatasi\nc) Phlebotomus argentipes\nd) Phlebotomus chinensis

Answer 192

Answer: c\nExplanation: Phlebotomus argentipes is the main vector responsible for transmitting visceral leishmaniasis (kala-azar) in India.

Question 193

19. Which diagnostic method is considered the gold standard for diagnosing visceral leishmaniasis?\na) PCR for Leishmania DNA\nb) Serology\nc) Blood smear examination\nd) Bone marrow biopsy

Answer 193

Answer: d\nExplanation: Bone marrow biopsy is considered the gold standard for diagnosing visceral leishmaniasis because it allows direct visualization of amastigotes in the reticuloendothelial system.

Question 194

20. Which condition is a common complication of visceral leishmaniasis?\na) Leukopenia\nb) Hyperthyroidism\nc) Meningitis\nd) Hepatitis

Answer 194

Answer: a\nExplanation: Leukopenia, or a reduction in white blood cell count, is a common complication of visceral leishmaniasis.

Question 195

21. Leishmania braziliensis is primarily associated with which form of leishmaniasis?\na) Visceral leishmaniasis\nb) Muco-cutaneous leishmaniasis\nc) Post-kala-azar dermal leishmaniasis\nd) Cutaneous leishmaniasis

Answer 195

Answer: b\nExplanation: Leishmania braziliensis is the primary species responsible for causing muco-cutaneous leishmaniasis, which involves destructive ulcerations of the mucosa.

Question 196

22. Post-kala-azar dermal leishmaniasis commonly presents with:\na) Enlarged liver and spleen\nb) Macular, maculo-papular, or nodular rash\nc) Fever and weight loss\nd) Severe anemia and jaundice

Answer 196

Answer: b\nExplanation: Post-kala-azar dermal leishmaniasis is characterized by a rash, which can be macular, maculo-papular, or nodular in nature. It often occurs as a complication after treatment for visceral leishmaniasis.

Question 197

23. Which of the following is NOT a typical symptom of visceral leishmaniasis (kala-azar)?\na) Splenomegaly\nb) Fever\nc) Lymphadenopathy\nd) Lung collapse

Answer 197

“Answer: d\nExplanation: Lung collapse is not a symptom of visceral leish

Question 198

Question and Options

Answer 198

Answer and Explanation

Question 199

58. The most common clinical feature of visceral leishmaniasis is: \na) Fever \nb) Weight gain \nc) Skin rash \nd) Cough

Answer 199

Answer: a \nExplanation: The most common clinical feature of visceral leishmaniasis is fever, often accompanied by weight loss, anemia, and splenomegaly.

Question 200

59. Which type of immune response is primarily involved in combating leishmaniasis? \na) Humoral immunity \nb) Cell-mediated immunity \nc) Innate immunity \nd) Passive immunity

Answer 200

Answer: b \nExplanation: Cell-mediated immunity is crucial for controlling Leishmania infections, particularly through the action of T cells and macrophages.

Question 201

60. The drug of choice for treating visceral leishmaniasis is: \na) Amphotericin B \nb) Metronidazole \nc) Acyclovir \nd) Doxycycline

Answer 201

Answer: a \nExplanation: Amphotericin B is considered the drug of choice for treating visceral leishmaniasis due to its efficacy against Leishmania parasites.

Question 202

61. Which laboratory technique is used to visualize Leishmania amastigotes in tissue samples? \na) PCR \nb) Blood smear \nc) Culture \nd) Histopathology

Answer 202

Answer: d \nExplanation: Histopathology allows for the visualization of Leishmania amastigotes within tissue samples, confirming the diagnosis.

Question 203

62. Leishmania parasites primarily enter the human host through: \na) Ingestion \nb) Skin abrasions \nc) Inhalation \nd) Sandfly bites

Answer 203

Answer: d \nExplanation: Leishmania parasites enter the human host primarily through bites from infected phlebotomine sandflies.

Question 204

63. Which demographic is most at risk for visceral leishmaniasis? \na) Healthy adults \nb) Children and immunocompromised individuals \nc) Elderly individuals \nd) Pregnant women

Answer 204

Answer: b \nExplanation: Children and immunocompromised individuals are at higher risk for developing visceral leishmaniasis due to weaker immune responses.

Question 205

64. The presence of Leishmania amastigotes is typically confirmed in which of the following tests? \na) Serology \nb) Blood culture \nc) Bone marrow aspirate \nd) Liver biopsy

Answer 205

Answer: c \nExplanation: The presence of Leishmania amastigotes is typically confirmed through a bone marrow aspirate, where the parasites can be visualized.

Question 206

65. Which of the following factors increases susceptibility to visceral leishmaniasis? \na) Good nutrition \nb) HIV infection \nc) Regular exercise \nd) Vaccination

Answer 206

Answer: b \nExplanation: HIV infection significantly increases susceptibility to visceral leishmaniasis by compromising the immune system.

Question 207

66. The clinical features of cutaneous leishmaniasis typically include: \na) Fever and weight loss \nb) Skin ulcers and lesions \nc) Joint pain \nd) Abdominal pain

Answer 207

Answer: b \nExplanation: Cutaneous leishmaniasis typically presents with skin ulcers and lesions at the site of infection.

Question 208

67. Which form of leishmaniasis can cause fatal complications if untreated? \na) Cutaneous leishmaniasis \nb) Muco-cutaneous leishmaniasis \nc) Visceral leishmaniasis \nd) Post-kala-azar dermal leishmaniasis

Answer 208

Answer: c \nExplanation: Visceral leishmaniasis can cause fatal complications if left untreated due to its systemic effects.

Question 209

68. The major reservoir host for cutaneous leishmaniasis is: \na) Cats \nb) Dogs \nc) Rodents \nd) Humans

Answer 209

Answer: c \nExplanation: Rodents are major reservoir hosts for cutaneous leishmaniasis, facilitating transmission through sandflies.

Question 210

69. Which of the following is a characteristic of visceral leishmaniasis in children? \na) Severe anemia \nb) High fever \nc) Skin lesions \nd) Joint swelling

Answer 210

Answer: a \nExplanation: Severe anemia is a characteristic feature of visceral leishmaniasis in children due to bone marrow involvement.

Question 211

70. In endemic regions, the most effective control measure against leishmaniasis is: \na) Vaccination \nb) Vector control \nc) Antibiotic treatment \nd) Education and awareness

Answer 211

Answer: b \nExplanation: Vector control is the most effective measure to reduce transmission of leishmaniasis in endemic regions.

Question 212

Question and Options

Answer 212

Answer and Explanation

Question 213

40. The characteristic fever in kala-azar is: \na) Low-grade and persistent \nb) High-grade with daily fluctuations \nc) Intermittent with evening spikes \nd) Continuous without fluctuation

Answer 213

Answer: c \nExplanation: The characteristic fever in kala-azar is intermittent with evening spikes, often accompanied by malaise and weight loss.

Question 214

41. Which factor plays a crucial role in the increasing incidence of visceral leishmaniasis? \na) High vaccination rates \nb) Environmental degradation \nc) HIV co-infection \nd) Frequent sandfly eradication programs

Answer 214

Answer: c \nExplanation: HIV co-infection is a crucial factor contributing to the increasing incidence of visceral leishmaniasis.

Question 215

42. Which organ is commonly affected in visceral leishmaniasis, leading to anemia and leukopenia? \na) Kidneys \nb) Lungs \nc) Bone marrow \nd) Heart

Answer 215

Answer: c \nExplanation: The bone marrow is infiltrated by Leishmania parasites, leading to suppression of red and white blood cell production, which causes anemia and leukopenia.

Question 216

43. Which is NOT a vector for transmitting visceral leishmaniasis? \na) Phlebotomus argentipes \nb) Lutzomyia longipalpis \nc) Phlebotomus martini \nd) Anopheles mosquito

Answer 216

Answer: d \nExplanation: Anopheles mosquitoes are vectors for malaria, not leishmaniasis. Sandflies like Phlebotomus and Lutzomyia are responsible for transmitting leishmaniasis.

Question 217

44. The pathogenesis of visceral leishmaniasis primarily involves: \na) Destruction of liver cells \nb) Invasion of red blood cells \nc) Parasite multiplication in macrophages \nd) Attack on the nervous system

Answer 217

Answer: c \nExplanation: The pathogenesis of visceral leishmaniasis involves Leishmania parasites multiplying inside macrophages, leading to widespread infection of the reticuloendothelial system.

Question 218

45. Kala-azar (visceral leishmaniasis) is also known as: \na) Black sickness \nb) African sleeping sickness \nc) Espundia \nd) River blindness

Answer 218

Answer: a \nExplanation: Kala-azar is also called black sickness due to the darkening of the skin seen in advanced cases of the disease.

Question 219

46. The definitive diagnosis of leishmaniasis involves: \na) Clinical symptoms only \nb) Identification of parasites in tissue samples \nc) Serology alone \nd) Ultrasound of the spleen

Answer 219

Answer: b \nExplanation: Definitive diagnosis of leishmaniasis is made by identifying Leishmania parasites in tissue samples such as bone marrow, spleen, or lymph nodes.

Question 220

47. What is the most effective treatment combination for leishmaniasis? \na) Pyrimethamine and sulphonamides \nb) Chloroquine and doxycycline \nc) Amphotericin B and pentavalent antimonials \nd) Metronidazole and clindamycin

Answer 220

Answer: a \nExplanation: The combination of pyrimethamine and sulphonamides is effective for treating both human and animal leishmaniasis cases.

Question 221

48. Which form of leishmaniasis is typically fatal if left untreated? \na) Cutaneous leishmaniasis \nb) Muco-cutaneous leishmaniasis \nc) Visceral leishmaniasis \nd) Post-kala-azar dermal leishmaniasis

Answer 221

Answer: c \nExplanation: Visceral leishmaniasis (kala-azar) is fatal if left untreated, due to its systemic effects on vital organs like the spleen, liver, and bone marrow.

Question 222

49. Which test is most widely used for the detection of antibodies to Toxoplasma gondii? \na) Complement fixation test \nb) Direct agglutination test \nc) Sabin-Feldman dye test \nd) Hemagglutination test

Answer 222

Answer: c \nExplanation: The Sabin-Feldman dye test is the most widely used and sensitive serological test for detecting antibodies to Toxoplasma gondii.

Question 223

50. Which of the following is NOT a serological test for diagnosing Toxoplasma gondii infection? \na) Complement fixation test \nb) Direct agglutination test \nc) Hemagglutination test \nd) Gram stain test

Answer 223

Answer: d \nExplanation: The Gram stain test is used to identify bacterial infections, not Toxoplasma gondii, which is a protozoan parasite. The other options are specific serological tests for toxoplasmosis.

Question 224

Question and Options

Answer 224

Answer and Explanation

Question 225

Which of the following stages of Plasmodium is injected into humans by mosquitoes? a) Gametocytes b) Sporozoites c) Merozoites d) Ookinetes

Answer 225

Answer: b) Sporozoites; Explanation: Sporozoites are the infectious form of Plasmodium injected into the human bloodstream by the female Anopheles mosquito during a blood meal.

Question 226

What happens to Plasmodium merozoites after they leave the liver? a) They become gametocytes b) They invade red blood cells (RBCs) c) They transform into sporozoites d) They remain in the bloodstream

Answer 226

Answer: b) They invade red blood cells (RBCs); Explanation: After the liver stage, merozoites are released into the bloodstream, where they invade RBCs and continue their asexual multiplication cycle.

Question 227

Which of the following is a symptom of Blackwater fever? a) Dark-red or black urine b) Hypoglycemia c) Jaundice d) All of the above

Answer 227

Answer: d) All of the above; Explanation: Blackwater fever is characterized by dark urine, jaundice, and sometimes hypoglycemia due to massive destruction of RBCs.

Question 228

Algid malaria is associated with which of the following? a) High blood pressure b) Cold, clammy skin c) Increased urine output d) Increased blood glucose levels

Answer 228

Answer: b) Cold, clammy skin; Explanation: Algid malaria results in circulatory collapse, leading to cold and clammy skin and low blood pressure.

Question 229

Which malaria parasite species is most commonly associated with severe malaria and cerebral malaria? a) Plasmodium ovale b) Plasmodium vivax c) Plasmodium falciparum d) Plasmodium malariae

Answer 229

Answer: c) Plasmodium falciparum; Explanation: P. falciparum is known for causing severe and cerebral malaria, which can be life-threatening.

Question 230

The gold standard for diagnosing malaria is through which of the following methods? a) Clinical diagnosis b) Rapid Diagnostic Tests (RDTs) c) Microscopy d) PCR testing

Answer 230

Answer: c) Microscopy; Explanation: Microscopy, specifically light microscopy, remains the gold standard for detecting and identifying malaria parasites.

Question 231

One major advantage of Rapid Diagnostic Tests (RDTs) over microscopy is that they: a) Are more sensitive b) Do not require electricity c) Can distinguish between Plasmodium species d) Provide permanent records

Answer 231

Answer: b) Do not require electricity; Explanation: RDTs are more practical in field settings because they don’t require electricity, unlike microscopy.

Question 232

What characteristic is unique to the detection of Histidine-rich protein II (HRP-II) in Rapid Diagnostic Tests (RDTs)? a) It is present in all Plasmodium species b) It is only produced by P. falciparum c) It distinguishes between P. vivax and P. ovale d) It detects mature gametocytes

Answer 232

Answer: b) It is only produced by P. falciparum; Explanation: HRP-II is produced by trophozoites and young gametocytes of P. falciparum, making it specific to this species.

Question 233

Which of the following is a preventive measure for malaria? a) Use of chloroquine b) Administering doxycycline c) Insecticide-treated nets d) All of the above

Answer 233

Answer: d) All of the above; Explanation: Malaria prevention involves the use of drugs like chloroquine, doxycycline, and protective measures such as insecticide-treated nets.

Question 234

What is the main reason for renal failure in Blackwater fever? a) Overproduction of urine b) Haemoglobin buildup in the kidneys c) Dehydration d) Excessive glucose in the blood

Answer 234

Answer: b) Haemoglobin buildup in the kidneys; Explanation: In Blackwater fever, the massive breakdown of erythrocytes releases free haemoglobin, which accumulates in the kidneys, leading to renal failure.

Question 235

In algid malaria, the circulatory collapse results in which of the following? a) Increased cardiac output b) Low blood pressure c) Fever without chills d) High peripheral blood flow

Answer 235

Answer: b) Low blood pressure; Explanation: Algid malaria involves circulatory collapse, which causes low blood pressure and cold, clammy skin.

Question 236

What is a major cause of the development of drug resistance in malaria? a) Overuse of RDTs b) Overdiagnosis and overtreatment c) Poor nutrition d) Use of untreated bed nets

Answer 236

Answer: b) Overdiagnosis and overtreatment; Explanation: Overdiagnosis and overtreatment increase drug pressure on malaria parasites, facilitating the development of drug resistance.

Question 237

Which Plasmodium stage is involved in the erythrocytic cycle? a) Gametocytes b) Merozoites c) Sporozoites d) Ookinetes

Answer 237

Answer: b) Merozoites; Explanation: Merozoites are involved in the erythrocytic cycle, where they invade RBCs and multiply.

Question 238

The rapid development of shock in malaria is referred to as: a) Cerebral malaria b) Algid malaria c) Blackwater fever d) Mild malaria

Answer 238

Answer: b) Algid malaria; Explanation: Algid malaria is a severe form characterized by circulatory collapse and rapid development of shock.

Question 239

Which diagnostic method for malaria provides a permanent record of the results? a) RDT b) Clinical diagnosis c) Light microscopy d) PCR

Answer 239

Answer: c) Light microscopy; Explanation: Light microscopy provides a permanent slide record that can be reviewed and archived.

Question 240

The symptoms of severe malaria most often overlap with other febrile illnesses. What does this imply for diagnosis? a) It makes clinical diagnosis unreliable b) It makes microscopy unnecessary c) It simplifies the diagnosis process d) It leads to underdiagnosis

Answer 240

Answer: a) It makes clinical diagnosis unreliable; Explanation: The symptoms of malaria are non-specific, making clinical diagnosis unreliable without confirmation from lab-based methods.

Question 241

Why is malaria more severe in pregnant women? a) Due to a weakened immune system b) High parasite load c) Poor nutrition d) Lack of prenatal care

Answer 241

Answer: a) Due to a weakened immune system; Explanation: Pregnant women have a reduced immune response, making them more susceptible to severe forms of malaria.

Question 242

What is the consequence of reduced glucose concentration in severe malaria cases? a) Anaemia b) Hyperglycemia c) Hypoglycemia d) None of the above

Answer 242

Answer: c) Hypoglycemia; Explanation: Hypoglycemia is a common symptom in severe malaria, particularly with P. falciparum infection, due to the parasite’s metabolic activity.

Question 243

What is the primary goal of malaria prophylaxis? a) To increase the immune response b) To prevent the disease before exposure c) To kill the vector d) To provide temporary immunity

Answer 243

Answer: b) To prevent the disease before exposure; Explanation: Malaria prophylaxis involves the use of drugs and other measures to prevent infection before exposure to malaria.

Question 244

What is the main vector control strategy against malaria? a) Residual insecticide spraying b) Mass vaccination c) Treatment with quinine d) Use of antipyretics

Answer 244

Answer: a) Residual insecticide spraying; Explanation: Vector control through residual insecticide spraying remains one of the most effective strategies against malaria transmission.

Question 245

Endophily refers to the mosquito’s tendency to: a) Rest outdoors b) Bite outdoors c) Rest indoors d) Bite indoors

Answer 245

Answer: c) Rest indoors; Explanation: Endophily is the tendency of mosquitoes to rest indoors after feeding.

Question 246

What does the term ‘zoophily’ indicate in relation to mosquito feeding habits? a) Preference for human blood b) Preference for animal blood c) Feeding in dark environments d) Feeding during daytime

Answer 246

Answer: b) Preference for animal blood; Explanation: Zoophily indicates the preference of mosquitoes to feed on animals rather than humans.

Question 247

What are the feeding and resting habits of vectors in relation to human habitation, and how do they influence malaria control?

Answer 247

Answer: The feeding and resting habits of malaria vectors, particularly mosquitoes, are categorized by their preferences for human or animal blood and their tendencies to rest or bite indoors or outdoors. These characteristics influence control strategies: Anthropophily: Refers to the vector’s preference for human blood, which makes them more dangerous for human populations. Zoophily: Indicates a preference for animal blood, which may divert mosquitoes from humans, reducing transmission risks. Endophagy: Refers to vectors that bite indoors, making indoor residual spraying (IRS) more effective. Exophagy: Indicates outdoor biting, making indoor interventions less effective. Endophily: Refers to vectors that rest indoors, again favoring IRS as a control method. Exophily: Refers to vectors that rest outdoors, reducing the efficacy of indoor spraying. Explanation: These behaviors guide the use of insecticides and the design of protective measures like bed nets and repellents, targeting mosquito behavior patterns to maximize the success of malaria control efforts. Understanding the feeding and resting habits allows for more strategic interventions in both endemic and epidemic regions.

Question 248

Explain how rapid diagnostic tests (RDTs) detect malaria and the advantages they offer over microscopy.

Answer 248

“Answer: Rapid diagnostic tests (RDTs) detect malaria by using immunochromatographic methods to identify antigens from malaria parasites in lysed blood. The tests employ monoclonal antibodies that target parasite antigens such as histidine-rich protein II (HRP-II) from Plasmodium falciparum or parasite lactate dehydrogenase (pLDH) from all Plasmodium species. They can detect the presence of malaria in about 15 minutes. Advantages of RDTs: Simpler and faster to perform than microscopy. Do not require electricity,

Question 249

Explain how rapid diagnostic tests (RDTs) detect malaria and the advantages they offer over microscopy.

Answer 249

Answer: Rapid diagnostic tests (RDTs) detect malaria by using immunochromatographic methods to identify antigens from malaria parasites in lysed blood. The tests employ monoclonal antibodies that target parasite antigens such as histidine-rich protein II (HRP-II) from Plasmodium falciparum or parasite lactate dehydrogenase (pLDH) from all Plasmodium species. They can detect the presence of malaria in about 15 minutes. Advantages of RDTs: Simpler and faster to perform than microscopy. Do not require electricity, special equipment, or expert technicians. Can detect infections even when parasites are sequestered in deep vascular compartments, which may be missed by microscopy. They are also useful in remote or resource-limited settings, improving access to malaria diagnosis and treatment.

Question 250

Discuss the lifecycle of Plasmodium and the significance of each stage in malaria transmission.

Answer 250

Answer: The lifecycle of Plasmodium consists of two main phases: the asexual phase in humans and the sexual phase in mosquitoes. Key stages include: 1. Sporozoites: Injected by mosquitoes, they travel to the liver where they mature into schizonts. 2. Schizonts: Undergo asexual replication, producing merozoites that are released into the bloodstream. 3. Merozoites: Infect red blood cells, leading to the clinical symptoms of malaria. 4. Gametocytes: Formed in RBCs and are taken up by mosquitoes during a blood meal. 5. In the mosquito: Gametocytes develop into gametes, fertilization occurs, and sporozoites form in the salivary glands, ready to infect another human. Each stage is crucial for the continuation of malaria transmission, highlighting the importance of targeting both the human and vector populations in control strategies.

Question 251

Identify the major challenges in malaria elimination efforts and potential strategies to overcome them.

Answer 251

Answer: Major challenges in malaria elimination include: 1. Drug resistance: Resistance to antimalarial drugs such as artemisinin poses a significant threat. Strategies: Continuous monitoring and development of new drugs. 2. Insecticide resistance: Mosquitoes developing resistance to insecticides can undermine vector control efforts. Strategies: Rotating insecticides, using combination treatments, and developing new vector control tools. 3. Environmental factors: Climate change and urbanization affect mosquito habitats and transmission dynamics. Strategies: Integrated vector management that considers environmental changes. 4. Access to healthcare: In many regions, access to diagnosis and treatment remains a challenge. Strategies: Strengthening health systems, increasing community health worker training, and improving logistics for drug delivery. Addressing these challenges requires a multifaceted approach involving research, policy, and community engagement.

Question 252

Explain the concept of herd immunity in the context of malaria prevention.

Answer 252

Answer: Herd immunity refers to the indirect protection from infectious diseases that occurs when a significant portion of a population becomes immune to the disease, either through vaccination or previous infections. In the context of malaria, achieving herd immunity can reduce transmission rates, protecting individuals who are not immune, such as young children and pregnant women. Strategies to enhance herd immunity include widespread use of malaria vaccines, effective treatment to reduce parasite reservoirs, and vector control measures that decrease overall malaria transmission within the community.

Question 253

What role do environmental factors play in malaria transmission, and how can they be managed?

Answer 253

Answer: Environmental factors, such as climate, topography, and human activities, significantly influence malaria transmission. Factors include: 1. Climate: Temperature and rainfall affect mosquito breeding and survival. Warmer temperatures can lead to increased mosquito populations. 2. Land use: Deforestation and agricultural practices can create new breeding sites. Management strategies: Implementing sustainable land use practices and maintaining wetlands. 3. Urbanization: Increases the risk of malaria in some regions due to increased human-mosquito interactions. Strategies: Urban planning that considers vector control measures and public health infrastructure. Effective management of these factors is crucial for malaria prevention efforts.

Question 254

Discuss the importance of community engagement in malaria control programs.

Answer 254

Answer: Community engagement is vital for the success of malaria control programs. Benefits include: 1. Increased awareness: Educating the community about malaria transmission and prevention fosters personal responsibility. 2. Improved treatment-seeking behavior: Engaged communities are more likely to seek timely diagnosis and treatment. 3. Participation in control efforts: Community involvement in vector control activities (e.g., clearing breeding sites) enhances program effectiveness. 4. Trust in healthcare systems: Community engagement builds trust, encouraging cooperation with health initiatives. Strategies to enhance community engagement include training local health workers, conducting outreach programs, and utilizing community leaders to disseminate information.

Question 255

Explain the significance of monitoring and evaluation in malaria control initiatives.

Answer 255

Answer: Monitoring and evaluation (M&E) are essential components of malaria control initiatives for several reasons: 1. Assessing effectiveness: M&E helps determine the impact of interventions, guiding resource allocation. 2. Identifying challenges: Regular evaluations can uncover barriers to implementation, allowing for timely adjustments. 3. Data-driven decision making: M&E provides data to inform policy changes and improve program strategies. 4. Accountability: M&E fosters transparency and accountability among stakeholders. To enhance M&E, it is crucial to develop robust data collection systems, train personnel, and establish clear indicators for success.

Question 256

What are the implications of malaria for maternal and child health?

Answer 256

Answer: Malaria significantly impacts maternal and child health in several ways: 1. Increased maternal morbidity and mortality: Pregnant women are at higher risk for severe malaria, leading to complications such as anemia and low birth weight. 2. Neonatal health: Infants born to mothers with malaria have an increased risk of low birth weight and mortality. 3. Delayed healthcare: Malaria in pregnancy can result in delays in seeking care, increasing the risk of adverse outcomes. Strategies to mitigate these impacts include integrating malaria prevention (e.g., insecticide-treated nets) into maternal health programs and ensuring prompt treatment for pregnant women.

Question 257

Describe the role of international partnerships in combating malaria.

Answer 257

Answer: International partnerships play a critical role in combating malaria by: 1. Coordinating efforts: Collaborative programs ensure that resources are used efficiently and interventions are harmonized across regions. 2. Funding and resource mobilization: International organizations provide funding, technical assistance, and resources to support malaria control efforts. 3. Research and innovation: Partnerships facilitate research on new treatments, vaccines, and vector control methods, accelerating progress against malaria. 4. Sharing best practices: Countries can learn from each other’s successes and challenges, improving local strategies. Successful partnerships involve governments, NGOs, and international organizations working together towards common goals.

Question 258

Explain the concept of herd immunity in the context of malaria prevention.

Answer 258

Answer: Herd immunity refers to the indirect protection from infectious diseases that occurs when a significant portion of a population becomes immune to the disease, either through vaccination or previous infections. In the context of malaria, achieving herd immunity can reduce transmission rates, protecting individuals who are not immune, such as young children and pregnant women. Strategies to enhance herd immunity include widespread use of malaria vaccines, effective treatment to reduce parasite reservoirs, and vector control measures that decrease overall malaria transmission within the community.

Question 259

What role do environmental factors play in malaria transmission, and how can they be managed?

Answer 259

Answer: Environmental factors, such as climate, topography, and human activities, significantly influence malaria transmission. Factors include: 1. Climate: Temperature and rainfall affect mosquito breeding and survival. Warmer temperatures can lead to increased mosquito populations. 2. Land use: Deforestation and agricultural practices can create new breeding sites. Management strategies: Implementing sustainable land use practices and maintaining wetlands. 3. Urbanization: Increases the risk of malaria in some regions due to increased human-mosquito interactions. Strategies: Urban planning that considers vector control measures and public health infrastructure. Effective management of these factors is crucial for malaria prevention efforts.

Question 260

Discuss the importance of community engagement in malaria control programs.

Answer 260

Answer: Community engagement is vital for the success of malaria control programs. Benefits include: 1. Increased awareness: Educating the community about malaria transmission and prevention fosters personal responsibility. 2. Improved treatment-seeking behavior: Engaged communities are more likely to seek timely diagnosis and treatment. 3. Participation in control efforts: Community involvement in vector control activities (e.g., clearing breeding sites) enhances program effectiveness. 4. Trust in healthcare systems: Community engagement builds trust, encouraging cooperation with health initiatives. Strategies to enhance community engagement include training local health workers, conducting outreach programs, and utilizing community leaders to disseminate information.

Question 261

Explain the significance of monitoring and evaluation in malaria control initiatives.

Answer 261

Answer: Monitoring and evaluation (M&E) are essential components of malaria control initiatives for several reasons: 1. Assessing effectiveness: M&E helps determine the impact of interventions, guiding resource allocation. 2. Identifying challenges: Regular evaluations can uncover barriers to implementation, allowing for timely adjustments. 3. Data-driven decision making: M&E provides data to inform policy changes and improve program strategies. 4. Accountability: M&E fosters transparency and accountability among stakeholders. To enhance M&E, it is crucial to develop robust data collection systems, train personnel, and establish clear indicators for success.

Question 262

What are the implications of malaria for maternal and child health?

Answer 262

Answer: Malaria significantly impacts maternal and child health in several ways: 1. Increased maternal morbidity and mortality: Pregnant women are at higher risk for severe malaria, leading to complications such as anemia and low birth weight. 2. Neonatal health: Infants born to mothers with malaria have an increased risk of low birth weight and mortality. 3. Delayed healthcare: Malaria in pregnancy can result in delays in seeking care, increasing the risk of adverse outcomes. Strategies to mitigate these impacts include integrating malaria prevention (e.g., insecticide-treated nets) into maternal health programs and ensuring prompt treatment for pregnant women.

Question 263

Describe the role of international partnerships in combating malaria.

Answer 263

Answer: International partnerships play a critical role in combating malaria by: 1. Coordinating efforts: Collaborative programs ensure that resources are used efficiently and interventions are harmonized across regions. 2. Funding and resource mobilization: International organizations provide funding, technical assistance, and resources to support malaria control efforts. 3. Research and innovation: Partnerships facilitate research on new treatments, vaccines, and vector control methods, accelerating progress against malaria. 4. Sharing best practices: Countries can learn from each other’s successes and challenges, improving local strategies. Successful partnerships involve governments, NGOs, and international organizations working together towards common goals.

Question 264

Discuss the potential impact of climate change on malaria transmission patterns.

Answer 264

Answer: Climate change can significantly affect malaria transmission patterns through several mechanisms: 1. Altered mosquito habitats: Changes in temperature and rainfall can expand or reduce suitable breeding sites for mosquitoes. 2. Increased vector survival: Warmer temperatures may enhance the lifespan of mosquitoes, leading to prolonged transmission seasons. 3. Geographic shifts: Malaria transmission may spread to new areas that were previously unsuitable due to climate conditions. 4. Impact on human populations: Vulnerable populations may face increased exposure to malaria as climatic conditions change. Strategies to address these impacts include climate adaptation measures and strengthening health systems to respond to evolving malaria risks.

Question 265

How does the economic burden of malaria affect affected countries?

Answer 265

Answer: The economic burden of malaria can have profound effects on affected countries through various channels: 1. Healthcare costs: Malaria treatment and prevention place a significant financial strain on healthcare systems. 2. Lost productivity: Illness and premature death due to malaria can lead to reduced workforce productivity, impacting economic growth. 3. Tourism and investment: High malaria prevalence can deter tourism and foreign investment, further hindering economic development. 4. Education: Malaria can lead to absenteeism in schools, affecting children’s education and future opportunities. Addressing the economic burden requires investment in effective malaria control measures and healthcare infrastructure.

Question 266

Explain the role of vaccines in malaria prevention.

Answer 266

Answer: Vaccines play a crucial role in malaria prevention by: 1. Providing immunity: Vaccines stimulate the immune system to recognize and combat malaria parasites, reducing the risk of infection. 2. Reducing transmission: Widespread vaccination can lower the overall number of infections in a community, contributing to herd immunity. 3. Complementing other strategies: Vaccination works alongside other preventive measures, such as insecticide-treated nets and antimalarial drugs. Current vaccine candidates, like RTS,S/AS01, aim to protect vulnerable populations, particularly children. Ongoing research is essential for developing more effective malaria vaccines.

Question 267

Identify the significance of integrated vector management in malaria control.

Answer 267

Answer: Integrated vector management (IVM) is significant in malaria control for several reasons: 1. Comprehensive approach: IVM combines multiple strategies (e.g., biological control, environmental management, chemical control) for effective vector control. 2. Sustainability: By addressing environmental factors and promoting community involvement, IVM aims for long-term solutions to vector control. 3. Reducing resistance: Integrating different control methods can help delay the development of resistance to insecticides. 4. Tailored interventions: IVM allows for context-specific strategies that consider local ecological and epidemiological factors, improving the effectiveness of malaria control efforts.

Question 268

Discuss the importance of community health workers in malaria control programs.

Answer 268

Answer: Community health workers (CHWs) are vital to malaria control programs due to their unique roles: 1. Local knowledge: CHWs understand community dynamics and can tailor interventions to meet local needs. 2. Outreach and education: They educate community members about malaria prevention and treatment, increasing awareness and compliance. 3. Early detection and treatment: CHWs can provide rapid diagnostic tests and initiate treatment, improving access to care. 4. Bridging gaps: They connect communities with formal healthcare systems, ensuring that vulnerable populations receive necessary services. Training and supporting CHWs enhance the overall effectiveness of malaria control strategies.

Question 269

Explain the concept of focal malaria transmission and its implications for control strategies.

Answer 269

Answer: Focal malaria transmission refers to localized outbreaks of malaria that occur in specific geographic areas, often due to unique environmental or social conditions. Implications for control strategies include: 1. Targeted interventions: Focal transmission requires focused efforts, such as enhanced surveillance and tailored control measures. 2. Resource allocation: Understanding focal transmission helps allocate resources efficiently, prioritizing high-risk areas. 3. Monitoring and evaluation: Ongoing monitoring is essential to detect and respond to outbreaks rapidly. 4. Community engagement: Engaging local populations in understanding and addressing transmission dynamics is crucial for effective control. Strategies must be adaptable to local contexts to mitigate risks.

Question 270

Discuss the role of public awareness campaigns in malaria prevention.

Answer 270

Answer: Public awareness campaigns play a critical role in malaria prevention by: 1. Educating communities: Raising awareness about malaria transmission, symptoms, and prevention measures fosters informed behaviors. 2. Promoting health-seeking behavior: Campaigns encourage individuals to seek timely diagnosis and treatment, reducing morbidity and mortality. 3. Enhancing community participation: Engaging communities in campaigns fosters ownership of malaria prevention efforts, promoting compliance with control measures. 4. Reducing stigma: Campaigns can help reduce stigma associated with malaria and increase acceptance of treatment and preventive measures. Effective campaigns utilize various communication channels to reach diverse audiences.

Question 271

Explain the role of technology in malaria diagnosis and treatment.

Answer 271

Answer: Technology plays a transformative role in malaria diagnosis and treatment by: 1. Enhancing diagnostic capabilities: Innovations such as molecular diagnostics and RDTs improve the accuracy and speed of malaria detection. 2. Mobile health solutions: Mobile applications can support data collection, health education, and treatment reminders, increasing access to care. 3. Telemedicine: Remote consultations facilitate access to expert care, especially in remote areas with limited healthcare resources. 4. Data analytics: Technology enables the analysis of malaria transmission patterns, guiding targeted interventions and resource allocation. Embracing technological advancements can significantly improve malaria control efforts.

Question 272

Question and Options

Answer 272

Answer and Explanation

Question 273

What is the primary indication for larval control? a) Rural areas b) Densely populated areas c) Coastal regions d) Forested areas

Answer 273

Answer: b) Densely populated areas Explanation: Larval control measures are most effective in densely populated areas with limited breeding places, such as urban regions and irrigated arid areas.

Question 274

Which of the following is a classical larvicide? a) Chlorine b) Paris green c) DDT d) Malathion

Answer 274

Answer: b) Paris green Explanation: Paris green is a classical larvicide used for controlling mosquito larvae, along with other substances like larvicidal oils and polystyrene beads.

Question 275

Who first discovered Toxoplasma gondii? a) Louis Pasteur b) Nicolle and Manceaux c) Robert Koch d) Joseph Lister

Answer 275

Answer: b) Nicolle and Manceaux Explanation: Toxoplasma gondii was first discovered in 1908 by Nicolle and Manceaux in a desert rodent.

Question 276

What type of parasite is Toxoplasma gondii? a) Bacterium b) Virus c) Obligate intracellular protozoan d) Fungi

Answer 276

Answer: c) Obligate intracellular protozoan Explanation: Toxoplasma gondii is classified as an obligate intracellular protozoan parasite, requiring a host cell to reproduce.

Question 277

In which species can Toxoplasma gondii be found? a) Only in felines b) Only in rodents c) Many species, including humans d) Only in primates

Answer 277

Answer: c) Many species, including humans Explanation: Toxoplasma gondii is found in a wide range of species, including carnivores, rodents, pigs, herbivores, primates, and birds.

Question 278

What is the first site of infection in cases of acute toxoplasmosis? a) Brain b) Liver c) Intestine d) Skin

Answer 278

Answer: c) Intestine Explanation: In most cases of acute toxoplasmosis, the intestine is the first site of infection where Toxoplasma gondii enters.

Question 279

What are tachyzoites? a) Dormant forms of Toxoplasma b) Rapidly dividing cells in acute infection c) Infective cysts d) Adult parasites

Answer 279

Answer: b) Rapidly dividing cells in acute infection Explanation: Tachyzoites are the rapidly dividing forms of Toxoplasma gondii during acute infections.

Question 280

Which symptoms are common in acute toxoplasmosis? a) Fever and headache b) Skin rash c) Abdominal cramps d) Nausea

Answer 280

Answer: a) Fever and headache Explanation: Common symptoms of acute toxoplasmosis include fever, headache, swollen lymph glands, and muscle pain.

Question 281

How is congenital toxoplasmosis transmitted? a) Through contaminated food b) Direct contact with infected animals c) Transplacental route from mother to fetus d) Airborne transmission

Answer 281

Answer: c) Transplacental route from mother to fetus Explanation: Congenital toxoplasmosis occurs when the parasite invades the fetus through the placenta after acute maternal infection.

Question 282

Which of the following is NOT a factor influencing the pathology of toxoplasmosis? a) Age of the host b) Virulence of the strain c) Host’s natural habitat d) Acquired immunity of the host

Answer 282

Answer: c) Host’s natural habitat Explanation: The natural habitat of the host does not directly influence the pathology of toxoplasmosis; instead, factors like age, strain virulence, and immunity are significant.

Question 283

What can chronic toxoplasmosis lead to in the brain? a) Tumors b) Nodules of cells c) Atrophy of neurons d) Increased synaptic connections

Answer 283

Answer: b) Nodules of cells Explanation: In chronic toxoplasmosis, the formation of cysts can lead to the development of nodules in the brain.

Question 284

Which serological test is most widely used for diagnosing Toxoplasma gondii? a) Complement fixation test b) Dye test (Sabin-Feldman) c) Hemagglutination test d) Direct agglutination test

Answer 284

Answer: b) Dye test (Sabin-Feldman) Explanation: The Sabin-Feldman dye test is a sensitive serological test widely used to detect antibodies against Toxoplasma gondii.

Question 285

Which of the following statements about Toxoplasma gondii is FALSE? a) It is a cosmopolitan parasite. b) It only infects cats. c) It can be transmitted congenitally. d) It can remain dormant in tissues.

Answer 285

Answer: b) It only infects cats Explanation: Toxoplasma gondii infects a wide range of hosts, not just cats.

Question 286

What is the main method of treatment for Toxoplasmosis? a) Antibiotics b) Combination of pyrimethamine and sulfonamides c) Antiviral drugs d) Surgery

Answer 286

Answer: b) Combination of pyrimethamine and sulfonamides Explanation: The most effective treatment for Toxoplasmosis in both humans and animals is a combination of pyrimethamine and sulfonamides.

Question 287

What is leishmaniasis primarily caused by? a) Bacteria b) Viruses c) Leishmania parasites d) Fungi

Answer 287

Answer: c) Leishmania parasites Explanation: Leishmaniasis is caused by several species of the Leishmania parasites, which are protozoans belonging to the Trypanosomidae family.

Question 288

What type of organism transmits leishmaniasis? a) Ticks b) Mosquitoes c) Phlebotomine sandflies d) Fleas

Answer 288

Answer: c) Phlebotomine sandflies Explanation: Phlebotomine sandflies are the known vectors responsible for transmitting leishmaniasis.

Question 289

Which form of leishmaniasis is characterized by skin ulcers? a) Visceral leishmaniasis b) Mucocutaneous leishmaniasis c) Cutaneous leishmaniasis d) Post-Kala-azar dermal leishmaniasis

Answer 289

Answer: c) Cutaneous leishmaniasis Explanation: Cutaneous leishmaniasis is characterized by the formation of skin ulcers at the site of the sandfly bite.

Question 290

What is a common symptom of visceral leishmaniasis? a) Skin lesions b) Fever and weight loss c) Nausea d) Diarrhea

Answer 290

Answer: b) Fever and weight loss Explanation: Visceral leishmaniasis, also known as kala-azar, commonly presents with fever, weight loss, and splenomegaly.

Question 291

Which of the following diseases can be caused by congenital toxoplasmosis? a) Hydrocephalus b) Malaria c) Typhoid d) Meningitis

Answer 291

Answer: a) Hydrocephalus Explanation: Congenital toxoplasmosis can lead to malformations such as hydrocephalus, microcephaly, and chorioretinitis.

Question 292

What kind of lesions are associated with subacute toxoplasmosis? a) Mild rashes b) Extensive lesions in multiple organs c) Benign tumors d) Ulcers

Answer 292

Answer: b) Extensive lesions in multiple organs Explanation: Subacute toxoplasmosis can cause extensive lesions, particularly in the lungs, heart, liver, brain, and eyes.

Question 293

Which tissue is primarily affected by Toxoplasma gondii during acute infection? a) Muscle b) Nervous tissue c) Intestinal epithelium d) Skin

Answer 293

Answer: c) Intestinal epithelium Explanation: The intestinal epithelium is primarily affected during the initial acute infection stage of Toxoplasma gondii.

Question 294

Which of the following is NOT a method for diagnosing Toxoplasmosis? a) Serology b) Tissue biopsy c) Blood culture d) Imaging studies

Answer 294

Answer: d) Imaging studies Explanation: While imaging studies can help assess damage, they are not a direct diagnostic method for Toxoplasmosis; serology and tissue biopsy are more relevant.

Question 295

Question and Options

Answer 295

Answer and Explanation

Question 296

What effect do cyst walls have on bradyzoites? a) They protect them from host defenses b) They facilitate their rapid multiplication c) They enhance their toxicity d) They allow them to disperse in the environment

Answer 296

Answer: a) They protect them from host defenses. Explanation: The cyst walls provide protection for bradyzoites from the host’s immune system, allowing them to survive in a dormant state within the host’s tissues.

Question 297

Which form of leishmaniasis is known for causing lesions in the mucous membranes? a) Cutaneous leishmaniasis b) Visceral leishmaniasis c) Mucocutaneous leishmaniasis d) Zoonotic leishmaniasis

Answer 297

Answer: c) Mucocutaneous leishmaniasis. Explanation: Mucocutaneous leishmaniasis is characterized by lesions affecting the mucous membranes, particularly of the nose and mouth.

Question 298

What is the primary diagnostic method for leishmaniasis? a) Blood culture b) Serological tests c) Tissue biopsy and microscopic examination d) PCR (Polymerase Chain Reaction)

Answer 298

Answer: c) Tissue biopsy and microscopic examination. Explanation: Tissue biopsy and microscopic examination of the affected tissues are the primary methods for diagnosing leishmaniasis, allowing for the identification of Leishmania amastigotes.

Question 299

Explain the life cycle of Toxoplasma gondii.

Answer 299

Answer: The life cycle of Toxoplasma gondii involves both definitive and intermediate hosts. The definitive host is typically a cat, where the parasite undergoes sexual reproduction, resulting in the shedding of oocysts in the feces. These oocysts can contaminate food and water, leading to infection in various intermediate hosts, including humans, rodents, and livestock. Inside the intermediate host, the oocysts develop into tachyzoites, which multiply rapidly and can infect various tissues. Eventually, some tachyzoites differentiate into bradyzoites, forming cysts that can remain dormant for long periods.

Question 300

Describe the common symptoms associated with acute toxoplasmosis.

Answer 300

Answer: Common symptoms of acute toxoplasmosis can include fever, muscle aches, fatigue, swollen lymph nodes, and headaches. Some individuals may experience flu-like symptoms, and in more severe cases, ocular symptoms such as blurred vision or eye pain can occur if the parasite infects the eyes. Immunocompromised individuals may experience more severe manifestations.

Question 301

What are the potential complications of congenital toxoplasmosis?

Answer 301

Answer: Congenital toxoplasmosis can lead to several serious complications, including hydrocephalus (accumulation of fluid in the brain), microcephaly (abnormally small head), chorioretinitis (inflammation of the retina), and intracranial calcifications. Other potential issues may include developmental delays and other neurological impairments.

Question 302

Explain the mechanism of action of pyrimethamine and sulfonamides in treating toxoplasmosis.

Answer 302

Answer: Pyrimethamine is an antiprotozoal agent that inhibits dihydrofolate reductase, an enzyme critical for folate metabolism in protozoa. This inhibition disrupts DNA synthesis, preventing the growth and reproduction of the Toxoplasma gondii parasite. Sulfonamides complement this action by inhibiting the synthesis of folic acid, which is necessary for nucleic acid synthesis. The combination of these drugs leads to a synergistic effect, enhancing the treatment’s efficacy against Toxoplasmosis.

Question 303

Discuss the role of phlebotomine sandflies in the transmission of leishmaniasis.

Answer 303

Answer: Phlebotomine sandflies are the primary vectors responsible for the transmission of Leishmania parasites to humans. When a female sandfly bites an infected host, it ingests the Leishmania promastigotes, which can then develop into infectious forms within the sandfly’s gut. Upon biting another host, the sandfly injects these parasites through its saliva, leading to infection. The transmission cycle is heavily influenced by the ecological conditions that support sandfly populations, such as temperature, humidity, and availability of breeding sites.

Question 304

Identify the different clinical forms of leishmaniasis and their characteristics.

Answer 304

Answer: Leishmaniasis presents in three primary clinical forms: Cutaneous leishmaniasis: Characterized by skin ulcers at the bite site, which can be painless or painful. Lesions may take months to heal and can lead to scarring. Visceral leishmaniasis (kala-azar): A severe form affecting internal organs, causing symptoms like prolonged fever, weight loss, splenomegaly, and anemia. It can be fatal if left untreated. Mucocutaneous leishmaniasis: Involves lesions in the mucous membranes of the nose and mouth, leading to significant disfigurement and secondary infections.

Question 305

Explain the significance of serological tests in the diagnosis of Toxoplasma gondii infection.

Answer 305

Answer: Serological tests play a critical role in diagnosing Toxoplasma gondii infections by detecting specific antibodies (IgM and IgG) produced by the host in response to infection. The presence of IgM indicates recent infection, while IgG signifies past exposure. These tests help distinguish acute from chronic infections, assess the risk of congenital transmission in pregnant women, and guide treatment decisions. Additionally, they are essential for screening immunocompromised patients at risk for reactivation of latent infections.

Question 306

What factors influence the pathology and clinical outcomes of leishmaniasis?

Answer 306

Answer: Several factors influence the pathology and clinical outcomes of leishmaniasis, including the species of Leishmania involved, the host’s immune response, the route of transmission, and the presence of co-infections. The virulence of the specific Leishmania strain can affect the severity of symptoms. Host factors, such as genetic predisposition and nutritional status, also play crucial roles. The overall health of the host’s immune system significantly determines the clinical outcome, with immunocompromised individuals being more susceptible to severe forms of the disease.

Question 307

Discuss the impact of environmental factors on the transmission of leishmaniasis.

Answer 307

Answer: Environmental factors significantly affect the transmission dynamics of leishmaniasis. Changes in land use, such as deforestation and urbanization, can alter the habitats of sandflies and their rodent hosts, potentially increasing human exposure to infected sandflies. Climatic conditions like temperature and humidity also play a critical role in the lifecycle of the sandfly vector, with warmer and more humid environments favoring their proliferation. Additionally, seasonal variations can influence the incidence of leishmaniasis outbreaks, particularly in regions where vectors are more active during specific months.

Question 308

Explain the treatment options for leishmaniasis.

Answer 308

Answer: Treatment options for leishmaniasis vary based on the clinical form of the disease and the patient’s condition. Common treatment regimens include: Pentavalent antimonials (e.g., sodium stibogluconate): These are the first-line treatment for most forms of leishmaniasis, effective in both cutaneous and visceral cases. Amphotericin B: Used for severe visceral leishmaniasis, especially in cases where first-line treatments fail. Miltefosine: An oral drug that can be used for both cutaneous and visceral leishmaniasis, particularly in pregnant women. Paromomycin: An alternative treatment option for cutaneous leishmaniasis, particularly in patients who cannot tolerate antimonials. Local treatments: Such as cryotherapy or topical agents, may be effective for cutaneous leishmaniasis in specific cases. Treatment choice depends on the geographical location, local guidelines, and the individual patient’s health status.

Question 309

What preventive measures can be taken to avoid Toxoplasma gondii infection?

Answer 309

Answer: Preventive measures to avoid Toxoplasma gondii infection include: Cooking meat thoroughly: Ensuring that meat is cooked to safe internal temperatures can kill the parasite. Avoiding raw or undercooked meat: Particularly pork and lamb, which are common sources of Toxoplasma. Practicing good hygiene: Washing hands thoroughly after handling raw meat, soil, or cat litter can reduce the risk of infection. Avoiding contact with cat feces: Pregnant women should take precautions to avoid handling cat litter, as oocysts are shed in the feces of infected cats. Washing fruits and vegetables: Cleaning produce properly can eliminate any potential contamination.

Question 310

How does the immune response differ between acute and chronic toxoplasmosis?

Answer 310

Answer: In acute toxoplasmosis, the immune response is characterized by a rapid activation of the innate immune system, leading to the production of pro-inflammatory cytokines and the recruitment of immune cells to the site of infection. This response helps to control the initial tachyzoite proliferation. In chronic toxoplasmosis, the immune system transitions to a more regulated response, often involving the production of IgG antibodies and the formation of tissue cysts containing bradyzoites. The immune system’s ability to contain the infection without completely eradicating the parasite leads to a balance where the host remains asymptomatic while the parasite persists.

Question 311

What are the challenges in controlling leishmaniasis in endemic areas?

Answer 311

“Answer: Controlling leishmaniasis in endemic areas faces several challenges, including: Vector control: The difficulty of effectively controlling sandfly populations due to their breeding sites often being in inaccessible or environmentally sensitive areas. Lack of resources: Limited financial and healthcare resources in many endemic regions hinder the implementation of effective control programs and access to treatment. Cultural practices: Local customs and practices, such as housing conditions or animal husbandry, may facilitate transmission and complicate prevention efforts. Environmental changes: Factors such as deforestation, urbanization, and climate change can alter the habitats of both sandflies and reservoir hosts, impacting transmission dynamics. Asymptomatic cases: Many individuals with cutaneous leishmaniasis remain asymptomatic, complicating surveillance and control