Khalil G. Ghanem, M.D.
- 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 parvum: intracellular protozoan parasite related to parasite that causes malaria (Plasmodium)
- Ingestion of sporulated oocysts (4-6 m in diameter) containing 4 sporozoites, which excyst and attach to colonic epithelium; these mature to meronts, which release merozoites leading to zygote formation; oocyst then released through feces into environment.
- Environmental oocysts can survive for many months.
- Person-to-person transmission among family members and close contacts tends to occur because infectious dose relatively small (<1000 oocysts); zoonotic transmission also possible; most outbreak cases due to contaminated water (BMJ 1991).
- In-hospital person-to-person transmission among patients w/ AIDS thought to be rare (Clin Infect Dis 2000).
- Most common cause of chronic diarrhea in severely immunosuppressed (CD4 <100).
- Med. time from exposure to Sx ~13d in pts. w/ AIDS
- Sx: large volume (scant in some cases), nonbloody, non-inflammatory diarrhea; occasional crampy abdominal pain; occasional low-grade fever; N&V may accompany diarrhea.
- DDx: Microsporidium, Cyclospora, Isospora, MAC, Giardia, Entamoeba, & Clostridium difficile.
- Other manifestations: acalculous cholecystitis (chronic carriage in gallbladder may make eradication of intestinal disease difficult), cholangiopathy; pancreatitis; sinusitis & tracheitis described; reactive arthritis.
- Stool/duodenal aspirate/bile smears; concentration techniques (e.g. FEA concentration) should be routinely performed to increase sensitivity.
- Modified Kinyoun's acid-fast stain is mainstay of Dx; oocysts stain red. DFA used occasionally to confirm Dx of suitable oocysts.
- Giemsa stain (purple oocysts), methenamine-silver (clear oocysts, dark background) have also been used.
- Multiple smears may be necessary as shedding can be intermittent. Duodenal Bx rarely needed.
- Commercial serology (EIA), stool IFAuncommonly used (mostly in outbreak settings where large volumes of studies are performed and results needed promptly); PCR mostly of research interest.
- Immune reconstitution w/ HAART is the only proven cure (Lancet 1998)
- Effectiveness of antiparasitics in patients w/ AIDS without immune reconstitution has been disappointing.
- Paromomycin 500mg PO tid (w/ meals) x14-28d OR 1g PO bid x14-28d followed by 0.5-1g PO bid is commonly used agent.
Azithromycin in combination w/ paromomycin has also been used. (J Infect Dis 1998)
- Nitazoxanide approved for immune-competent children; recent study in HIV-infected pts suggests reasonable response rate (ref #10) at dose of 500-1500 mg mg PO bid
- 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 tid-qid prn
- Antiperistaltics: deodorized tincture of opium (DTO) 0.3-1 ml PO qid prn.
- Other: bismuth sub-salicylate and NSAIDs
- Octreotide: 100 mcg SQ tid up to 250 mcg SQ tid; limited efficacy data.
- Use bottled water (filtered through 1 m filter), or boil water for 1 min.
- Avoid raw shellfish
- Can be transmitted from person to person through ingestion of contaminated water (drinking water & water used for recreational purposes) or food, from animal to person, or by contact with fecally contaminated environmental surfaces.
||Commonly used antiparasitic agent, though results in clinical trials have been inconsistent.
||Limited but positive data in HIV-infected adults (see ref #10); approved in immunocompetent children.
||No in vivo data
||Typically used in combination with paromomycin; limited data
- Paromomycin 0.5-1.0 g PO bid may be used chronically in those who respond while awaiting immune reconstitution.