Parasitology Flashcards
3 differences between strongyloides and hookworm larvae on microscopy
- Buccal Cavity - Hookworm has a large buccal cavity, strongioides has a short buccal cavity
- Genital primordium - Hookworm is inconspicuous, strongiloides is visible
- End - Strongiloides has a notched end while hookworms is tapered
3 risk factors for severe disease with Babesia
1) Increasing Age
2) Splenectomy
3) Immune Compromise
Treatment of Babesia
Atovaquone 750 mg po q12h PLUS
Azithromycin 1 g po x 1, then 500 mg po daily
x 7-10 days
Do not treat if mild, asymptomatic disease
Name 3 helminths in which Wolbachia species play a symbiotic role
1) Brugia malayi
2) Onchocerca volvulus
3) Wuchereria bancrofti
What do Giardia Antigen tests detect?
Cyst wall proteins
3 ways of acquiring Giardia infection?
1) Ingestion of cysts from contaminated water
2) Person-person spread (fecal oral ie. daycare, MSM)
3) Food borne
How many Giardia cysts have to be ingested to develop symptomatic infection?
10-25
(Varies between isolate and assemblage)
2 assemblages infect humans: A and B
Where in the body do Giardia trophozoites multiply?
Upper small bowel
Incubation period of Giardia lamblia?
1-2 weeks
3 extraintestinal manifestations of Giardia?
1) Urticaria
2) Eye complaints
3) Reactive Arthritis
Sn and Sp of Giardia Antigen EIAs?
Sn = 85-95% Sp = 90-100%
Treatment for Giardia
Metronidazole 250 mg po TID x 7 days
2 Alternative treatment for Giardia?
1) Albendazole 400 mg po daily x 5 days
2) Parmomycin 500 mg po TID x 5-10 days
1 post Giardia complication?
Lactose intolerance
4 parasites that can cause gastrointestinal symptoms and peripheral eosinophilia
1) Dientamoeba fragilis
2) Strongiloides
3) Ascaris
4) Hookworm
Organism associated with Dientamoeba infections?
Enterobius vermicularis (pinworm)
5 clinical manifestations of Cryptosporidium infection in AIDS patients besides diarrhea and abominal pain?
1) Cholecystitis
2) Cholangitis
3) Hepatitis
4) Pancreatitis
5) Respiratory tract involvement
4 stains used to detect Cryptosporidium?
1) Modified Acid Fast Stain (Kinyoun)
2) Hematoxylin & Eosin
3) Geimsa
4) Malachite Green
What is the treatment for Cryptosporidium infection in healthy patient and patient with AIDS?
Healthy = No treatment, self limiting AIDS = Optimize HIV medications plus Nitazoxanide 500-1000 mg PO BID x 14 days
Life cycle of Toxoplasmosis?
Humans infected by either eating cysts in the tissue of animals, or eating the decal oocysts from cat feces. The disease circles between cats and animals. In humans the cysts become tachyzoites and infect tissues including placenta and fetus.
Triad of congenital toxoplasmosis?
1) Hydrocephalus
2) CNS calcifications (diffuse, CMV around ventricles)
3) Chorioretinitis
Treatment for neonatal toxoplasmosis?
Sulfadiazine + Pyrimethamine
If fetus infected with toxoplasmosis what is the treatment?
Sulfadiazine + Pyrimethamine
If mom is infected but amniocentesis is negative how to prevent transmission to the fetus?
Spiramycin
