NOTE: Stool for Ova & Parasites (O&Ps) requires 3 specimens on separate days.
Giardia (most common parasite)- Best test: fresh stool for Giardia Antigen
- Risks: Travel (3rd World, Russia), wilderness hiking, MSM
- Pathogen: Entamoeba histolitica (risk: 3rd World travel)
- Non-Pathogen: E. dispar, E. moshkovskii (common among gay men)
- Distinguish by sending fresh stool for Antigen Detection
- Serology for E. histolitica useful if negative
- E. histolitica causes dysentery & liver abscesses
- Rare in U.S. (maybe common in rural Southeast)
- Risk: 3rd World travel
- Suspect if eosinophilia
- Risk: 3rd World travel. Can persist for decades
- Suspect if eosinophilia
- O&P’s poor; order ELISA serology for immunocompetent persons
- Very hard Dx in immunocompromised
- Probably not pathogenic
- Thus, no documented Tx
- Suggestion: Tx for Giardia w/ low-dose Metronidazole (250 mg TID x5d)
See posting Chronic Diarrhea.