Lisa A. Spacek, MD, PhD and Khalil G. Ghanem, MD, PhD
- Cryptosporidiosis endemic in Zambia and is common cause of persistent diarrhea in HIV+ Zambians.
- Diagnostic testing is limited in Zambia; diarrhea typically treated empirically per routine guidelines (see diarrhea).
- If cryptosporidiosis specifically diagnosed, treatment recommendations are same as in developed world.
- Nitazoxanide is novel treatment for cryptosporidiosis that has been studied specifically in Zambian patients with AIDS and persistent diarrhea. In one small study, it was demonstrated to have modest benefit.
- Prevention techniques listed below apply to Zambia.
Zambia Information Author: Larry William Chang, MD, MPH
Cryptosporidium: intracellular protozoan parasite. Most common species infecting humans are C. hominis, C. parvum, and C. meleagridis.
- Sporulated oocysts (4-6 micrometers in diameter) are ingested, then excyst and attach to intestinal epithelium; trophozoites mature to meronts, which release merozoites leading to zygote formation; oocysts then released through feces into environment.
- In immunocompromised pts, parasites develop intracellularly throughout GI tract, within epithelial cells of biliary tree and pancreatic ducts. Infection causes loss of villi, crypt hyperplasia, and reduction in brush border enzyme activity.
- Environmental oocysts infectious when shed, small in size, can survive for at least 6 mos (if kept moist), and are resistant to chlorination. Sensitive to hydrogen peroxide, ozone and UV radiation.
- Person-to-person transmission among family members and close contacts tends to occur because infectious dose is small (as few as 10 oocysts); zoonotic transmission also possible; most outbreak cases due to contaminated water, as in 1993 Milwaukee, Wisconsin outbreak.
- Most common cause of chronic diarrhea in severely immunosuppressed (CD4 <100). Accounts for 10-20% of diarrheal episodes.
- Med. time from exposure to Sx ~13d in pts. w/ AIDS
- Sx: frequent, foul-smelling, watery (scant in some cases), non-bloody, non-inflammatory diarrhea; occasional crampy abdominal pain; occasional low-grade fever; N&V. Weight loss and nutrient malabsorption may accompany diarrhea.
- DDx: Microsporidia, Cyclospora, Isospora, MAC, Giardia, Entamoeba, & Clostridium difficile.
- Other manifestations: acalculous cholecystitis (chronic carriage in gallbladder may make eradication difficult), sclerosing cholangitis and pancreatitis due to papillary stenosis; sinusitis & tracheitis described; reactive arthritis.
- Stool/duodenal aspirate/bile smears; concentration techniques (e.g., formalin ether or formalin-ethyl acetate methods) should be routinely performed to increase sensitivity.
- Direct immunofluorescence using monoclonal abs offers highest sensitivity and specificity.
- Modified Kinyoun's acid-fast stain for differential staining; oocysts stain red.
- Giemsa stain (purple oocysts) may not distinguish from yeast forms.
- For profuse diarrhea, single stool specimen usually adequate. Duodenal Bx rarely needed.
- Commercial serology (EIA), stool IFA used mostly in outbreak settings where large volumes of studies are performed and results needed promptly; PCR mostly of research interest.
- Ultrasound evaluates bile ducts and gallbladder. ERCP for visualization and Bx.
- ART with immune restoration to a CD4 >100 is mainstay of treatment.
- Nitazoxanide 0.5 to 1.0 gm PO twice-daily with food x 2 wks.
- Data do NOT support the use of paromomycin for cryptosporidiosis.
- Diet: high-fiber & low fat; frequent small meals; avoid caffeine and lactose.
- Antiperistaltics: loperamide (Imodium) 4 mg PO x1, then 2 mg PO prn, up to 16 mg/d
- Antiperistaltics: atropine/diphenoxylate (Lomotil): 1-2 tabs PO three times a day - four times a day prn
- Antiperistaltics: deodorized tincture of opium (DTO) 0.3-1 ml PO four times a day prn.
- Use bottled water (filtered through 1 micrometer filter) or boil water for 3 min.
- Avoid exposure to feces, farm animals, domestic pets with diarrhea.
- Wear gloves and wash hands after potential exposure i.e., handling pets, diapering, gardening.
- Recommendations from CDC, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America ;
Guidelines for Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents ;
2009 ; Vol.
58 ; pp.
Basis for recommendation
Comments:Guidelines for OI prevention and treatment released April 10, 2009.
- Abubakar I, Aliyu SH, Arumugam C, et al. ;
Prevention and treatment of cryptosporidiosis in immunocompromised patients. ;
Cochrane Database Syst Rev ;
2007 ; Vol.
1 ; pp.
Basis for recommendation
Comments:Seven trials involving 169 pts, including 130 adults with AIDS in 5 studies. Although data showed no reduction in duration or frequency of diarrhea for nitazoxanide or paramomycin vs placebo, due to efficacy of nitazoxanide seen in immunocompetent children, its use is recommended in AIDS pts.