Parasite 4 Flashcards
Describe the transmission of Babesia microti, what is its tropism?
found only in human blood cells, transmitted by the deer tick (usually nymph of Ixodes scapularis) with mice and small mammals as the intermediate host (humans incidental hosts); also through blood transfusion
most common in the northeast and upper midwest
How is babesia dx, and treated, what are the symptoms?
usually asymptomatic, some hemolytic anemia and non-specific flu-like symptoms; some will have splenomegaly, hepatomegaly or jaundice
Dx: microscopy ID babesia inside the RBC (diagnostic maltoses cross), tx with combo atovaquone and azithromycin for 7-10d
What are the organisms that cause malaria and their distribution?
Plasmodium falciparum: mostly Africa, many in SE Asia
P. vivix: mostly Asia an S. America
P. knowlesi: SE Asia (24h)
P. ovale: some in African and few in Asia
P. malariae: small portion of those in Asia and S. America (72 hr)
How is malaria transmitted?
transmitted by the bite of female Anopheles mosquitos (or congental and needle transfer) with definitive host the mosquito and intermediate hosts humans
range mostly falls within the “tropics,” risk for fatality is highest in children and prima gravid females; most morbidity and mortality is due to P. falciparum
Which strains can relapse due to latent hepatic forms?
P. ovale and P. vivax
Which strains have a 48hr spike and which have a 72hr spike, note if the fever is broad or sharp.
P. vivax and P. oval: 48 hr spike
P. malariae 72hr spike
P. falciparum 48hr broad
What are the symptoms of malaria?
anemia due to erythrocyte destruction
chills (actual low temp), fever, splenomegaly, myalgia, headache
cerebral malaria in P. falciparum
What mechanisms does malaria use to evade the immune system while in the blood stream?
produces and exports knob proteins to the RBC so it is stick and adheres to the vasculature and other RBC
