Blood Born Parasites - Part 2 Flashcards
What transmits Babesia?
Ticks
What is the reservoir for Babesia?
White-footed mouse
What other pathogen has the same prevalence and distribution as Babesia?
Borrelia burgdorferi (Lyme Disease)
How is Babesiosis diagnosed?
Clinical suspicion (ask questions), findings of hemolytic anemia and thrombocytopenia, light microscopy of multiple blood smears
Tx for Babesia
7-10 day treatment with atovaquone+azithromycin OR clindamycin+quinine (stnd of care for severe disease)
How does one clinically differentiate Babesia from Malaria?
Use Geimsa stain for correct Dx. Those with malaria will have malarial pigment which are fingely granular deposits within the RBC left as a byproduct of Hb degradation
What transmits Anaplasma phagocytophilum?
Ixodes tick
What are the reservoirs for Anaplasma phagocytophilum?
White-footed mouse and squirrels
Describe the Erlichia/Anaplasma Life Cycle. What are the two forms of the bug? Which form is reproductive?
A. phagocytophilum disseminates to bone marrow and spleen. Elementary body (non-reproductive) attaches to cell surface platelet selectin ligand-1 (PSGL-1). Reticulate form is reproductive.
How is Erlichia/Anaplasma Dx?
On blood film, morulae (multiple body structures of bug w/i cell) are observed; Ab titer; Whole blood PCR
What is Chagas Disease? Vector? Intracellular or Extracellular pathogen? Sites of dissemination?
Infection by Trypanosoma cruzi (American Trypanosomiasis) spread by the Reduvid bug; Extracellular; Heart (Cardiomyopathy), Esophagus (Megaesophagus), Colon (Megacolon)
Distribution of Trypanosoma cruzi
South America, Mexico, Southern to Middle Texas, South California
What are the two forms of the disease? What is the determining factor of disease severity?
Acute (Death w/i a few weeks) Chronic (Syx may not manifest for 5-10 years. Worse prognosis if bug in Amastigote form.
What is Romana’s sign?
Periorbital swelling associated with Trypanosome infection
Leishmaniasis vector? Site of replication? Sites of infection?
Sand fly; Histiocytes; Cutaneous, Mucocutaneous, Visceral
Clinical manifestations of Leishmaniasis
Cutaneous - chronic skin ulcers, normally at site of inoculation; Mucocutaneous - dissemination of bug to mouth, nose pharynx; Visceral: Fever, weightloss, hepatosplenomegaly
Leishmaniasis Dx
Skin biopsies, touch preps with Giemsa stain
What bug is the leading cause of death attributed to food borne illness in the US?
Toxoplasmosis
How is Toxoplasmosis transmitted?
Fecal-oral spread from cats, or ingestion of undercooked food
Toxoplasmosis Syx in immunocompetent hosts?
Asymptomatic, if it occurs, flu-like Syx, latent unless patient is immunocompromised.
What are the concerns of Toxoplamosis infection in pregnant women?
If a woman is infected just before or during pregnancy, she will pass the pathogen to the baby causing miscarriage, stillborn, or child born with toxoplasmosis
Describe Ocular Toxoplasmosis
Retinochoroiditis, acute inflammatory lesion resulting in eye pain, photophobia, eye tearing, blurred vision; Reactive disease can cause blindness
Describe pathogenesis of Toxoplasmosis in Immunosuppressed patients
Immunocomp. patients may have reactivated Toxo resulting in fever, confusion, seizures, nausea. CNS toxo is a complication of late HIV disease
What is Filariasis caused by? What are the Syx? What is the geographic distribution?
Caused by nematodes (roundworms) Wuchereria bancrofti and Brugia malayi; Lymphadenitis, irregular fever, lymphedema, elephantiasis; Equatorial distribution (similar to malaria)
