Blood Born Parasites - Part 2

Question 1

What transmits Babesia?

Answer 1

Ticks

Question 2

What is the reservoir for Babesia?

Answer 2

White-footed mouse

Question 3

What other pathogen has the same prevalence and distribution as Babesia?

Answer 3

Borrelia burgdorferi (Lyme Disease)

Question 4

How is Babesiosis diagnosed?

Answer 4

Clinical suspicion (ask questions), findings of hemolytic anemia and thrombocytopenia, light microscopy of multiple blood smears

Question 5

Tx for Babesia

Answer 5

7-10 day treatment with atovaquone+azithromycin OR clindamycin+quinine (stnd of care for severe disease)

Question 6

How does one clinically differentiate Babesia from Malaria?

Answer 6

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

Question 7

What transmits Anaplasma phagocytophilum?

Answer 7

Ixodes tick

Question 8

What are the reservoirs for Anaplasma phagocytophilum?

Answer 8

White-footed mouse and squirrels

Question 9

Describe the Erlichia/Anaplasma Life Cycle. What are the two forms of the bug? Which form is reproductive?

Answer 9

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.

Question 10

How is Erlichia/Anaplasma Dx?

Answer 10

On blood film, morulae (multiple body structures of bug w/i cell) are observed; Ab titer; Whole blood PCR

Question 11

What is Chagas Disease? Vector? Intracellular or Extracellular pathogen? Sites of dissemination?

Answer 11

Infection by Trypanosoma cruzi (American Trypanosomiasis) spread by the Reduvid bug; Extracellular; Heart (Cardiomyopathy), Esophagus (Megaesophagus), Colon (Megacolon)

Question 12

Distribution of Trypanosoma cruzi

Answer 12

South America, Mexico, Southern to Middle Texas, South California

Question 13

What are the two forms of the disease? What is the determining factor of disease severity?

Answer 13

Acute (Death w/i a few weeks) Chronic (Syx may not manifest for 5-10 years. Worse prognosis if bug in Amastigote form.

Question 14

What is Romana’s sign?

Answer 14

Periorbital swelling associated with Trypanosome infection

Question 15

Leishmaniasis vector? Site of replication? Sites of infection?

Answer 15

Sand fly; Histiocytes; Cutaneous, Mucocutaneous, Visceral

Question 16

Clinical manifestations of Leishmaniasis

Answer 16

Cutaneous - chronic skin ulcers, normally at site of inoculation; Mucocutaneous - dissemination of bug to mouth, nose pharynx; Visceral: Fever, weightloss, hepatosplenomegaly

Question 17

Leishmaniasis Dx

Answer 17

Skin biopsies, touch preps with Giemsa stain

Question 18

What bug is the leading cause of death attributed to food borne illness in the US?

Answer 18

Toxoplasmosis

Question 19

How is Toxoplasmosis transmitted?

Answer 19

Fecal-oral spread from cats, or ingestion of undercooked food

Question 20

Toxoplasmosis Syx in immunocompetent hosts?

Answer 20

Asymptomatic, if it occurs, flu-like Syx, latent unless patient is immunocompromised.

Question 21

What are the concerns of Toxoplamosis infection in pregnant women?

Answer 21

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

Question 22

Describe Ocular Toxoplasmosis

Answer 22

Retinochoroiditis, acute inflammatory lesion resulting in eye pain, photophobia, eye tearing, blurred vision; Reactive disease can cause blindness

Question 23

Describe pathogenesis of Toxoplasmosis in Immunosuppressed patients

Answer 23

Immunocomp. patients may have reactivated Toxo resulting in fever, confusion, seizures, nausea. CNS toxo is a complication of late HIV disease

Question 24

What is Filariasis caused by? What are the Syx? What is the geographic distribution?

Answer 24

Caused by nematodes (roundworms) Wuchereria bancrofti and Brugia malayi; Lymphadenitis, irregular fever, lymphedema, elephantiasis; Equatorial distribution (similar to malaria)

Question 25

Clinical manifestations of lymphatic Filariasis

Answer 25

Elephantiasis - lymph blockage resulting in massive edema caused by Wuchereria bancrofti and Brugia malayi

Question 26

What is Onchocerciasis? What is it caused by? What is the vector? Region? Infection and pathogenesis?

Answer 26

River blindness! Filarial worm Ochocerca volvulus and is spread by the black fly. Africa; When microfilariae (immature larva) die under skin, they cause swelling, inflammation and intense scaly dermatitis. When microfilariae migrate to eye and die, cause blindness

Question 27

What is Loa loa? What is the vector? Where do the larvae tend to live

Answer 27

Filarial parasite; from the Chrysops flys. In subcutus and superficial eye.