Blood And Tissue Parasites

Question 1

PLASMODIUM

Answer 1

• mosquito bite introduces sporozoites.
• Asexual reproduction (schizogony) in parenchymal cells (hepatocytes) of the liver.
• Hepatocytes rupture releasing merozoites that attach to erythrocytes and start erythrocytes cycle.
• sexual reproductive stage within the mosquito is necessary for the maintenance of malaria within a population.

Question 2

P. Falciparum

Answer 2

• no selectivity in host erythrocytes and invades any red blood cell,
• multiple merozoites can infect a single erythrocyte,
• seen in the host cell at the very edge or periphery of the cell membrane.

-appliqué or accolé position
(stuck on side of cell).

• trophozoite stages and schizonts sequestered in the liver and spleen.
• blood smears contain only young ring forms.
• crescentic gametocytes are diagnostic. reddish granules known as Maurer dots.
• Co-infection with human immunodeficiency virus (HIV) is common.
• mosquito bite.
• 7 to 10 days. influenza-like symptoms followed by daily (quotidian) chills and fever and severe nausea, vomiting, and diarrhea.
• becomes tertian (36 to 48 hours), and fulminating disease develops.
• P. falciparum is the most likely to result in death if left untreated. (cerebral malaria).
• Kidney damage.
• blackwater fever.

-rapid destruction of RBCs produces a marked hemoglobinuria and can result in acute renal failure, tubular necrosis, nephrotic syndrome, and death.

Question 3

P. Knowlesi

Answer 3

• malaria parasite of Old World monkeys.
• It has a short life cycle of 24 hours (quotidian).
• parasite in RBCs is not synchronous.
• RBCs infected with P. knowlesi exhibit a normal morphology, and all developmental stages may be seen in peripheral blood.
• Malaysia;
• unique 24-hour erythrocyte cycle and its ability to infect all stages of RBCs.
• history of visiting woods or their vicinity in Southeast Asia.

Question 4

P. Vivax

Answer 4

• invades only young, immature erythrocytes.
• infected RBCs are usually enlarged and contain numerous pink granules.
• The most prevalent of the human plasmodia.
• Mosquito.
• 10 to 17 day incubation.
• vague influenza-like symptoms. chills, fever, and malarial rigors.
• high temperatures (103° F to 106° F).
• benign tertian malaria.
• spectrum of severe, life-threatening syndromes.
• Collect is midway between paroxysms of chills and fever, when the greatest number of intracellular organisms is present.
• supportive measures and chemotherapy.
• Chloroquine and . Primaquine.

Question 5

P. ovale

Answer 5

• selectivity for young, pliable erythrocytes.
• Schüffner dots appear as pale pink granules, and the cell border is frequently fimbriated or ragged.
• Mosquito.

Question 6

P. Malariae

Answer 6

• infect only mature erythrocytes.
• conform to the size and shape of the RBC.
• no red cell enlargement or distortion.
• reddish granules called Ziemann dots.
• Mosquito.
• incubation period for P. malariae is the longest of the plasmodia.
• Untreated infections may last as long as 20 years.
• Characteristic bar and band forms and the rosette schizont in thick and thin films of blood establishes the diagnosis.

Question 7

Bebesia

Answer 7

• Tick bite.
• deer, cattle, and rodents; humans are accidental hosts.
• Ixodes ticks. B. microti is the usual cause of babesiosis in the United States.
• those with a history of babesiosis are deferred indefinitely from donating blood.
• Presently, there is no FDA-approved screening test.
• general malaise, fever without periodicity, headache, chills, sweating, fatigue, and weakness.
• progresses with increased destruction of erythrocytes, hemolytic anemia develops, and the patient may experience renal failure.
• Hepatomegaly and splenomegaly can develop in advanced disease.
• Infected patients may have negative smears because of the low-grade parasitemia.

Question 8

Toxoplasma Gondii

Answer 8

• AIDS patients are more likely to have severe manifestations.
• eating undercooked contaminated meat;
• ingestion of oocysts contaminated with cat feces
• organ transplantation or blood transfusion
• transplacental transmission.
• hepatitis, encephalomyelitis, and myocarditis.
• chills, fever, headaches, and fatigue

Question 9

Sarcocystis lindemanni

Answer 9

(DON’T REALLY NEED TO KNOW)

– blood parasite, sheep, cattle pigs,

• Infected from eating meat, infection of heart muscle.
• RARE, no specific treatment

Question 10

FREE LIVING AMEBAE

Answer 10

ones that will eat your brain while swimming.

Warm months

not normally parasites.

Question 11

Leishmania

Answer 11

• sand fly,
• Intracellular parasite.
• Different species, can be cutaneous, muco-cutaneous, or visceral (more severe).
• Female sand fly bites you and you become infected.
• Can have Human-vector-Human transmission and Humans-zoonotic-human transmission.
• L. donovani, L. infantum, and L. chagasi commonly cause visceral leishmaniasis.

Question 12

T. Brucei gambiense

Answer 12

(Gambian sleeping sickness)

• Tsetse fly bite.
• shaded stream banks for reproduction and proximity to human dwellings.
• ulcer at the site of the fly bite.
• lymph nodes are invaded, and fever, myalgia, arthralgia, and lymph node enlargement result.
• Swelling of the posterior cervical lymph nodes is characteristic of Gambian disease and is called Winterbottom sign.

Question 13

T. Brucei rhodesiense

Answer 13

• cattle-raising countries, in which tsetse flies breed in the brush.
• Tsetse fly bite. (fever, rigors, and myalgia) occurs more rapidly and progresses to a fulminating, rapidly fatal illness.
• Infected persons are usually dead within 9 to 12 months if untreated..

Question 14

T. Cruzi

Answer 14

(Chagas)

Kissing bug disease