Malaria Flashcards
1
Q
A protozoan disease transmitted by infected female Anopheles mosquitoes.
A
Malaria
2
Q
Six Plasmodium species cause nearly all malarial infections in humans
A
P. falciparum (most deadly)
P. vivax
Two species of P. ovale (curtisi and wallikeri)
P. malariae
P. knowlesi (monkey malaria in Southeast Asia)
3
Q
Responsible for relapses in these species.
A
Hypnozoites
4
Q
When does the symptomatic stage of malaria begin?
A
When parasite densities reach ~50/μL of blood (~100 million total parasites in an adult’s blood).
5
Q
In what form is malaria inoculated by Anopheles mosquito into human during blood meal
A
Sporozoites
6
Q
In what form does malaria invade RBCs
A
Merozoite
7
Q
Merozoite in RBCs become ___-
A
trophozoite
8
Q
Duffy blood-group antigen Fy a or Fy b is crucial for P. ____ invasion
A
vivax
knowlesi (also)
9
Q
What causes malaria disease in humans?
A
Direct effects of the asexual parasite (RBC invasion and destruction) and the host’s reaction
10
Q
P. ____ is more common in Central/South America and Southeast Asia.
A
vivax
11
Q
Which mosquitoes are the most effective vectors of malaria?
A
Those that are long-lived, high in density, breed readily, and preferentially bite humans like Anopheles gambiae complex in Africa
12
Q
This type of transmission is constant, frequent, year-round infection (e.g., in hyper/holoendemic areas). Immunity is maintained, especially in adults, but symptoms often surge during the rainy season due to increased mosquito breeding.
A
Stable transmission
13
Q
This type of transmission is Low, erratic, or focal transmission (e.g., hypoendemic areas) where full immunity is not developed, making all age groups susceptible.
A
Unstable transmission
14
Q
____ mediates attachment to receptors on venular and capillary endothelium (cytoadherence).
A
PfEMP1
15
Q
Various vascular receptors identified for cytoadherence:
A
Intercellular adhesion molecule 1 and endothelial protein C receptor in the brain.
Chondroitin sulfate B in the placenta.
CD36 in most other organs.
16
Q
These infected RBCs may also adhere to uninfected RBCs (to form _____) and to other parasitized erythrocytes (_______)
A
rosettes
agglutination
17
Q
P. ____ and P. _____ prefer young RBCs
A
vivax
ovale
18
Q
P. ____ can invade RBCs of all ages, leading to potentially high parasite densities.
A
falciparum
19
Q
P. _____ infections may also result in dangerously high parasite densities due to the shorter 24-hour asexual life cycle.
A
knowlesi
20
Q
A genetic disorder with sixfold reduction in severe falciparum malaria mortality.
A
Sickle cell trait (HbA/S)
21
Q
A genetic disorder with reduced parasite growth and cytoadherence due to impaired PfEMP1 presentation
A
Hemoglobins S and C
22
Q
A genetic disorder that protects against severe P. falciparum and P. vivax infections.
A
G6PD deficiency
23
Q
Factors Hindering Cellular Immunity Development:
A
> Lack of major histocompatibility antigens on infected RBCs, preventing direct T-cell recognition.
Malaria-specific immune unresponsiveness.
Strain diversity of malarial parasites and variant antigen expression (e.g., changing surface antigens like PfEMP1 during infection).
Parasites may persist in the blood for long periods (months to years, or even decades for P. malariae) if untreated.
24
Q
Classic malarial paroxysms (fever spikes, chills, and rigors at regular intervals) are rare and suggest P. ___ or P. ___ infection or relapse.
A
vivax
ovale
25
Fever is usually irregular, especially in P. ____ infections, and may never become regular.
falciparum
26
The major clinical features of severe falciparum malaria
27
Features indicating a poor prognosis in severe falciparum malaria
28
A characteristic and ominous feature of falciparum malaria
Coma
29
Cerebral malaria presents as a diffuse symmetric encephalopathy T/F
True
30
What symptoms are specific to falciparum malaria?
Generalized seizures, potential for cerebral malaria
31
Differential diagnoses for malaria based on symptoms?
Meningitis (without neck stiffness, photophobia)
Dengue fever (less severe myalgia)
Leptospirosis, typhus (no muscle tenderness)
32
What are the symptoms of classic malarial paroxysms?
Fever spikes, chills, rigors at regular intervals
33
What are the typical manifestations of cerebral malaria?
diffuse symmetric encephalopathy
34
What funduscopic abnormalities are observed in cerebral malaria?
Retinal hemorrhages observed in 15% (up to 30–40% with dilation and indirect ophthalmoscopy)
Other abnormalities: retinal opacification, papilledema, cotton wool spots, vessel decolorization
35
An important and common complication of severe malaria, is associated with a poor prognosis and is particularly problematic in children and pregnant women.
Hypoglycemia
36
This medication may lead to hyperinsulinemic hypoglycemia, particularly problematic in pregnant women
Quinine
37
An important cause of death from severe malaria, which in adults is often compounded by coexisting renal impairment.
Acidosis
38
The best biochemical prognosticators in severe malaria
Plasma concentrations of bicarbonate or lactate
39
What can precipitate pulmonary edema in severe malaria?
Overly vigorous administration of IV fluid
40
Noncardiogenic pulmonary edema can develop in p. ___ and p. ___
falciparum
vivax
41
What might be the pathogenesis of renal failure in severe falciparum malaria?
Possibly related to erythrocyte sequestration and agglutination affecting renal microcirculation and metabolism.
Clinically and pathologically manifests as acute tubular necrosis.
42
What is the clinical recovery timeline for renal failure in malaria?
Median time for urine flow to resume is 4 days
Mean time for serum creatinine levels to return to normal is 17 days.
43
Hemoglobin levels of ≤__g/dL at presentation are associated with increased mortality.
3
44
Anemia in malaria results from:
Accelerated RBC removal by the spleen
Obligatory RBC destruction during parasite schizogony
Ineffective erythropoiesis
45
Acute hemolytic anemia with massive hemoglobinuria
“blackwater fever”
46
In endemic areas, what specific bacteremia is associated with P. falciparum infections?
Salmonella spp.
47
What infections are common in patients unconscious for more than 3 days?
chest infections
catheter-induced urinary tract infections
48
What is the impact of malaria in early pregnancy?
fetal loss
49
How does falciparum malaria affect birth weight and infant mortality
>low birth weight in primi- and secundigravid women (average reduction ~170 g)
>increased infant mortality rates.
49
How does P. vivax malaria affect birth weight in pregnancy?
reduced birth weight (average reduction ~110 g), more pronounced in multigravid than primigravid women.
50
How can malaria be transmitted outside of mosquito bites?
blood transfusion, needlestick injury, or organ transplantation.
51
What is unique about transfusion malaria?
No relapses in P. vivax and P. ovale infections since there are no liver stages
52
How are transfusion malaria cases managed compared to naturally acquired infections?
Primaquine is not needed for vivax or ovale malaria due to the absence of liver stages.
53
Malaria is not a clinical diagnosis. T/F
T
54
The definitive diagnosis of malaria
demonstration of asexual forms of the parasite in stained peripheral-blood smears
55
Childhood Burkitt’s lymphoma is strongly associated with Epstein-Barr virus (EBV) infection and areas with high transmission of P. _____ malaria.
falciparum
56
At least how many fields should be examined before deeming a thick smear negative
100–200
57
What is a limitation of RDTs in malaria diagnosis?
RDTs do not quantify parasitemia
58
_____ are widely used in malaria control programs to detect specific antigens in finger-prick blood samples, such as:
P. falciparum–specific histidine-rich protein 2 (PfHRP2).
Lactate dehydrogenase.
Aldolase.
RDT
59
In severe malaria, poor prognosis indicators include:
A predominance of mature P. falciparum parasites (>20% with visible pigment) in peripheral blood
Phagocytosed malarial pigment in >5% of neutrophils, indicating recent schizogony.
60
Patients with ____ parasites/μL are at higher risk of dying
>100,000
61
What are common hematological findings in acute malaria?
- Normochromic, normocytic anemia is usual.
- Leukocyte count generally normal, may increase in severe infections.
- Slight monocytosis, lymphopenia, eosinopenia; reactive lymphocytosis and eosinophilia post-infection.
- Platelet count usually reduced to ~105 /μL.
62
What laboratory findings in severe malaria?
>metabolic acidosis
>low plasma concentrations of glucose, sodium, bicarbonate, phosphate, and albumin
>elevations in lactate, BUN, creatinine, urate, muscle and liver enzymes, and conjugated and unconjugated bilirubin
63
What are typical cerebrospinal fluid findings in acute malaria?
CSF opening pressure ~160 mm H2O
slight elevation in total protein (<1.0 g/L or <100 mg/dL) and cell count (<20/μL).
64
What is the WHO's recommendation for first-line treatment of uncomplicated P. falciparum malaria?
Artemisinin-based combination therapy (ACT) for uncomplicated P. falciparum malaria
65
The recommended first-line treatment for P. knowlesi infections
ACT
66
Recommended treatment for the other malarias besides knowlesi and falciparum
Chloroquine
ACT
67
The drug of choice for all patients with severe malaria, reducing mortality by 35% in Asian patients and 22.5% in African children compared to quinine.
Parenteral Artesunate
68
In artemisinin-resistant severe P. falciparum cases from Southeast Asia, ____ and ______ are used together in full doses.
artesunate and quinine
69
It is recommended for pregnant women with severe malaria.
Artesunate
70
Quinidine must be administered carefully via controlled infusion to avoid dangerous _____
hypotension
71
If artesunate is unavailable, ___ or ____ can be used with an initial loading dose to reach therapeutic concentrations quickly.
artemether or quinidine
72
Convulsions should be treated promptly with ____
IV or rectal benzodiazepines
73
Nasogastric feeding should be delayed (____ in adults and 36 hours in children) to reduce the risk of aspiration pneumonia in non-intubated patients.
60 hours
74
When should blood transfusion be considered in severe malaria?
>If hematocrit falls below 20%, consider transfusion of whole blood or packed cells. >In high transmission areas, a threshold of 15% hematocrit is used.
75
What should be measured in unconscious patients with severe malaria?
>Blood glucose level should be measured every 4–6 h.
>All patients should receive a continuous infusion of dextrose, and blood concentrations ideally should be maintained above 4 mmol/L
76
The parasite count and hematocrit should be measured every ___
6–12 h
77
When should oral therapy be initiated?
As soon as the patient can take fluids, switch to oral therapy and complete a 3-day course of ACT.
78
Treatment for severe vivax and knowlesi malaria should follow the same recommendations as for falciparum malaria. T/F
T
79
WHO-Recommended ACT Regimens:
Artemether-lumefantrine.
Artesunate-mefloquine.
Dihydroartemisinin-piperaquine.
Artesunate-sulfadoxine-pyrimethamine.
Artesunate-amodiaquine.
Artesunate-pyronaridine.
80
Pregnant women should not be given ____.
primaquine
81
Second-line treatments for recrudescence following first-line therapy
>different ACT regimen may be given
>another alternative is a 7-day course of either artesunate or quinine plus tetracycline, doxycycline, or clindamycin
82
Treatment for uncomplicated P. falciparum and P. knowlesi Infections:
artemisinin-based combination therapy (ACT) due to the propensity for high parasite densities and severe disease
83
Treatment for sensitive P. vivax, P. malariae, and P. ovale Infections
either with an ACT OR
oral chloroquine (total dose, 25 mg of base/kg)
84
Drug associated with higher rates of vomiting and dizziness.
Mefloquine
85
Extremely bitter and often leads to cinchonism (tinnitus, deafness, nausea, vomiting, dysphoria).
Oral quinine
86
In areas of low malaria transmission, a single dose of ______ (0.25 mg/kg) should be added to ACT as a P. falciparum gametocytocide to reduce the transmissibility of the infection.
primaquine
87
What steps should be taken if there is doubt about the malarial species infecting a patient?
Treat for falciparum malaria and check thick blood films again after 1 and 2 days later to exclude dx
88
What symptom is monitored after administering oral antimalarial drugs?
Vomiting
89
Symptom-based treatment, with ____ , lowers fever and thereby reduces the patient’s propensity to vomit these drugs
acetaminophen (paracetamol)
90
What drug exacerbates the orthostatic hypotension associated with malaria, and all are tolerated better by children than by adults
antimalarial quinolines (chloroquine, amodiaquine, mefloquine, and quinine)
91
Drug resistance is likely, and the treatment regimen should be changed if parasitemia does not fall ____ of the admission value in ___ or persists beyond ____
below 25%
72 hours
7 days
92
To eradicate persistent liver stages and prevent relapse (radical treatment), _____ (0.5 mg of base/kg in East Asia and Oceania and 0.25 mg/kg elsewhere) should be given once daily for ___ to patients with P. vivax or P. ovale infection after laboratory tests for ______have proved negative.
primaquine
14 days
G6PD deficiency
93
If the patient has a mild variant of G6PD deficiency, primaquine can be given in a dose of _____ once weekly for 8 weeks
0.75 mg of base/kg (maximum, 45 mg)
94
Pregnant women with vivax or ovale malaria should not be given ___ but should receive suppressive prophylaxis with ___ (5 mg of base/kg per week) until delivery, after which radical treatment can be given.
primaquine
chloroquine
94
What causes Acute Pulmonary Edema in malaria?
Caused by increased pulmonary capillary permeability.
95
What initial management steps should be taken for Acute Pulmonary Edema in malaria?
-Position patients with the head of the bed at a 45° elevation.
-Administer oxygen and IV diuretics.
96
What is the initial treatment for hypoglycemia in malaria?
An initial slow injection of 20% dextrose (2 mL/kg over 10 minutes)
Followed by an infusion of 10% dextrose (0.10 g/kg per hour).
97
When should hypoglycemia or gram-negative septicemia be suspected in malaria patients?
Suspected when the condition of a patient suddenly deteriorates during antimalarial treatment for no obvious reason.
98
How should spontaneous bleeding be managed in malaria patients?
Administer fresh blood and IV vitamin K.
99
The only drug advised for pregnant women traveling to areas with drug-resistant malaria, generally considered safe in the second and third trimesters of pregnancy
Mefloquine
*Chloroquine and proguanil are safe but have limited protective regions.
99
What is the treatment for convulsions in malaria patients?
Treat with IV or rectal benzodiazepines, and provide respiratory support if necessary.
100
What is the protocol for travelers regarding antimalarial prophylaxis?
- Start taking antimalarial drugs 2 days to 2 weeks before departure.
- Continue prophylaxis for 4 weeks after leaving the endemic area, except for atovaquone-proguanil or primaquine, which can be discontinued 1 week after departure.
101
IPT in pregnancy (IPTp) involves giving treatment doses of ____at each antenatal visit (maximum, once monthly) in the ___ and ___ trimesters of pregnancy.
sulfadoxine-pyrimethamine
second and third
102
What is the recommended prophylaxis for travelers to areas with drug-resistant malaria?
Atovaquone-proguanil, doxycycline, or mefloquine, with considerations for health risks and current medications.
103
What alternative strategies are being implemented for malaria prevention?
- Intermittent preventive treatment (IPT) for pregnant women and infants.
- Seasonal malaria chemoprevention (SMC) for young children.
104
Chemoprophylactic agent?
Effective against all malaria species, including multidrug-resistant P. falciparum.
Well tolerated and best taken with food for optimal absorption; avoid in patients with GFR <30 mL/min.
Atovaquone-Proguanil (Malarone; 3.75/1.5 mg/kg or 250/100 mg, daily adult dose)
105
Chemoprophylactic agent?
Daily dosing effective against multidrug-resistant P. falciparum.
Side effects include photosensitivity, diarrhea, and vaginal yeast infections.
Not recommended for children <8 years or pregnant women.
Doxycycline
106
Chemoprophylactic agent?
Effective in preventing drug-resistant P. falciparum and P. vivax.
G6PD deficiency must be excluded before use; safe only for non-pregnant adults.
Primaquine
107
Chemoprophylactic agent?
No longer reliable for P. falciparum but still used for other species and in regions with chloroquine-sensitive strains.
Safe for pregnancy but not effective in regions with high chloroquine resistance.
Chloroquine
108
It is contraindicated for use by travelers with known hypersensitivity and by persons with active or recent depression, anxiety disorder, psychosis, schizophrenia, another major psychiatric disorder, or seizures; it is not recommended for persons with cardiac conduction abnormalities, although the evidence that it is cardiotoxic is very weak.
Mefloquine
108
An effective chemoprophylactic agent alternative to atovaquone-proguanil or mefloquine
doxycycline
109
A 30-year-old woman who is 16 weeks pregnant is planning to travel to an area with known chloroquine-resistant Plasmodium falciparum. Which of the following is the most appropriate chemoprophylaxis for her?
A. Doxycycline
B. Mefloquine
C. Atovaquone-proguanil
D. Primaquine
B
110
A traveler plans to visit a region with high transmission of Plasmodium vivax and Plasmodium falciparum. He is concerned about taking medication for malaria prophylaxis. Which of the following agents requires G6PD deficiency screening before use?
A. Mefloquine
B. Atovaquone-proguanil
C. Doxycycline
D. Primaquine
D
Primaquine requires G6PD deficiency screening before use due to the risk of hemolysis in individuals with this deficiency.
111
Which of the following chemoprophylactic regimens is best for a traveler to a malaria-endemic region who has a history of anxiety disorder and reports experiencing vivid dreams and sleep disturbances with prior use of certain medications?
A. Mefloquine
B. Atovaquone-proguanil
C. Chloroquine
D. Primaquine
B
112
A 28-year-old man traveling to a malaria-endemic region is concerned about potential photosensitivity reactions with his malaria prophylaxis. Which of the following medications is most likely to cause photosensitivity?
A. Chloroquine
B. Doxycycline
C. Atovaquone-proguanil
D. Mefloquine
B
Atovaquone-proguanil is well tolerated and does not commonly cause neuropsychiatric side effects. Mefloquine can exacerbate neuropsychiatric symptoms and is contraindicated in individuals with a history of anxiety disorder or other psychiatric conditions.
113
A 45-year-old man with severe Plasmodium falciparum malaria is being treated with IV artesunate. Which of the following adjunctive treatments has been shown to be ineffective or harmful and should be avoided in the management of severe malaria?
A. IV diuretics
B. High-dose glucocorticoids
C. Antipyretics
D. IV glucose infusion
B
High-dose glucocorticoids, along with other adjunctive treatments such as urea, heparin, dextran, desferrioxamine, and mannitol, have been shown to be ineffective or harmful in severe malaria and should not be used.
114
A 25-year-old pregnant woman in her third trimester presents with a confirmed diagnosis of Plasmodium falciparum malaria. Which of the following is the most appropriate antimalarial therapy for this patient?
A. Artesunate
B. Mefloquine
C. Doxycycline
D. Primaquine
A. Artesunate is the drug of choice for severe malaria, including in pregnant women. Doxycycline and primaquine are contraindicated in pregnancy, and mefloquine is not indicated for severe malaria.
114
A 50-year-old man is being treated for severe malaria with quinidine. Which of the following is an important monitoring parameter for this patient during treatment?
A. Plasma glucose level every 4–6 hours
B. Liver function tests daily
C. Serum potassium every 8 hours
D. Erythrocyte sedimentation rate (ESR) every 12 hours
A. Monitoring plasma glucose levels every 4–6 hours is essential, as quinidine can cause hypoglycemia, especially in patients with severe malaria.
115
A 35-year-old man in a malaria-endemic region is found to have P. vivax infection. Laboratory testing confirms he is not G6PD deficient. Which of the following is the appropriate treatment for radical cure to prevent relapse?
A. Chloroquine for 3 days
B. Atovaquone-proguanil for 3 days
C. Primaquine daily for 14 days
D. Artesunate for 7 days
C. Primaquine daily for 14 days is the treatment for radical cure to eradicate liver stages of P. vivax and prevent relapse, especially after confirming G6PD deficiency status.
116
Which of the following malaria species is most commonly associated with high parasite densities and can cause severe malaria requiring immediate treatment with an artemisinin-based combination?
A. P. ovale
B. P. knowlesi
C. P. malariae
D. P. vivax
B
117
A 30-year-old man with severe malaria develops acute renal failure with rising blood urea nitrogen (BUN) and creatinine levels despite adequate rehydration. What is the next best step in management?
A. Increase fluid administration
B. Initiate early renal replacement therapy
C. Administer corticosteroids
D. Start diuretics
B
118
A 42-year-old woman traveling to a malaria-endemic area has been prescribed atovaquone-proguanil. She asks when she should stop taking the medication after leaving the endemic region. What is the correct advice?
A. Stop 2 days after leaving the area
B. Stop 1 week after leaving the area
C. Stop 2 weeks after leaving the area
D. Stop 4 weeks after leaving the area
B. Atovaquone-proguanil can be discontinued 1 week after leaving the endemic area due to its activity against liver stages of the infection.
119
A 60-year-old woman presents with severe P. falciparum malaria. After starting IV artesunate, her parasitemia has not fallen below 25% of the admission value after 72 hours. What is the most likely explanation?
A. Drug resistance
B. Poor absorption of artesunate
C. Inadequate dose adjustment for age
D. Reinfection with P. vivax
A
120
Which of the following is a characteristic side effect of oral quinine used in the treatment of uncomplicated malaria?
A. Hypertension
B. Cinchonism
C. Renal impairment
D. Severe allergic reaction
B
121
A 28-year-old man with P. falciparum malaria presents with acute respiratory distress syndrome (ARDS). Which of the following is the appropriate management strategy?
A. Immediate IV glucocorticoids
B. Positive-pressure ventilation
C. Increased fluid administration
D. Oral artesunate therapy
B
122
A 30-year-old man presents with fever after returning from a malaria-endemic area. Thick and thin blood smears are prepared but are reported as negative by an experienced microscopist. What is the most appropriate next step?
A. Repeat blood smears in 1 and 2 days
B. Start empirical antimalarial therapy
C. Perform an indirect fluorescent antibody test
D. Conclude that the patient does not have malaria
A
Thick blood films should be checked again 1 and 2 days later to exclude the diagnosis, as a single negative smear does not entirely rule out malaria.
123
A 35-year-old woman is suspected of having malaria, but reliable microscopy is unavailable. Which of the following diagnostic methods should be considered to confirm the diagnosis?
A. Indirect fluorescent antibody test
B. Rapid diagnostic test (RDT) detecting PfHRP2 antigen
C. Chest X-ray
D. Complete blood count
B. Rapid diagnostic tests (RDTs) detecting P. falciparum histidine-rich protein 2 (PfHRP2) antigen can be used when reliable microscopy is not available.
124
Which of the following is the main advantage of using thick blood films over thin blood films in malaria diagnosis?
A. Provides species identification
B. Concentrates parasites, increasing diagnostic sensitivity
C. Allows quantification of parasitemia
D. Requires no staining
B
125
A patient in a malaria-endemic region has a positive rapid diagnostic test (RDT) for P. falciparum using PfHRP2 antigen. Which of the following is a limitation of this test?
A. It cannot detect asymptomatic malaria
B. It does not remain positive after treatment
C. It cannot be used to identify other Plasmodium species
D. It does not quantify parasitemia
D
126
A 50-year-old man with suspected severe malaria has a thick blood film showing over 20% of parasites with visible pigment. What does this finding indicate?
A. Mild infection
B. Poor prognosis
C. Mixed P. falciparum and P. vivax infection
D. Drug resistance
B. The predominance of more mature P. falciparum parasites with visible pigment in over 20% of parasites in the peripheral blood film indicates a poor prognosis
127
A 45-year-old woman with P. falciparum malaria is found to have phagocytosed malarial pigment in more than 5% of neutrophils. What does this finding suggest?
A. Recent schizogony and severe malaria
B. A mixed infection with P. vivax
C. A resolved malaria infection
D. Drug resistance
A
128
Which of the following statements is true regarding the use of serologic testing for malaria diagnosis?
A. It is the most accurate method for acute malaria diagnosis
B. It helps determine drug resistance in malaria infections
C. It is useful for screening prospective blood donors
D. It can identify malaria species in real-time
C
129
A 32-year-old man with suspected malaria is found to have hypergammaglobulinemia on laboratory evaluation. Which of the following scenarios is this most consistent with?
A. Early acute infection
B. Severe P. falciparum malaria
C. A recent traveler from a non-endemic area
D. Long-term residence in a malaria-endemic area
D
130
Which of the following Plasmodium species is most commonly associated with severe malaria and the highest mortality rates?
A. Plasmodium vivax
B. Plasmodium ovale
C. Plasmodium falciparum
D. Plasmodium malariae
C
131
A 40-year-old man presents with fever, headache, fatigue, and abdominal discomfort after returning from a tropical country. Which of the following would be most indicative of a malaria diagnosis?
A. Regular fever spikes every 4 days
B. Fever associated with chills and rigors
C. Presence of a rash on physical examination
D. Photophobia and neck stiffness
B Fever associated with chills and rigors is characteristic of malaria, although the classic paroxysms are uncommon in P. falciparum infections.
132
Which of the following is a characteristic finding in severe P. falciparum malaria but is typically absent in infections with other Plasmodium species?
A. Hemoglobinuria
B. Sequestration of infected erythrocytes in vital organs
C. Tertian fever pattern
D. Splenomegaly
B
133
Which of the following Plasmodium species is known for having dormant liver forms (hypnozoites) that can cause relapses weeks to years after the initial infection?
A. P. falciparum
B. P. vivax
C. P. knowlesi
D. P. malariae
B. P. vivax (along with P. ovale) has dormant liver forms (hypnozoites) that can cause relapses.
134
Which of the following groups is most susceptible to severe manifestations of P. falciparum malaria in areas with unstable transmission?
A. Pregnant women
B. Elderly men
C. Adults with partial immunity
D. Infants only
A
135
Which clinical feature is most commonly associated with Plasmodium vivax and Plasmodium ovale malaria compared to other species?
A. Thrombocytopenia
B. Tertian fever patterns
C. Severe jaundice
D. Blackwater fever
B
136
A patient with P. falciparum malaria has developed acute pulmonary edema despite being on appropriate therapy. What is the likely cause of this complication?
A. Overhydration
B. Hypovolemia
C. Direct parasite invasion of the lungs
D. Increased pulmonary capillary permeability
D
137
Which of the following describes a key difference between P. falciparum and P. knowlesi infections?
A. Only P. falciparum invades erythrocytes of all ages
B. P. knowlesi has a 72-hour asexual life cycle
C. P. falciparum rarely causes severe illness
D. P. knowlesi infections typically lead to cerebral malaria
A
138
A 32-year-old woman presents with mild jaundice and fever after travel to a malaria-endemic area. She denies any significant past medical history. Which Plasmodium species is most likely to be associated with severe jaundice in this case?
A. P. vivax
B. P. ovale
C. P. falciparum
D. P. malariae
C
