Cryptosporidium parvum and Isospora belli infections among patients with and without diarrhoea.

OBJECTIVE

To assess the importance of Cryptosporidium parvum and Isospora belli infections as a cause of diarrhoea among patients admitted to the Medical Wards in Queen Elizabeth Central Hospital (QECH) in Blantyre, Malawi.

DESIGN

Prospective case control study.

SUBJECTS

One hundred and twenty one patients with diarrhoea and 122 patients without diarrhoea.

MAIN OUTCOME MEASURES

Demonstration of C. parvum and I. belli oocysts by examination of at least one stool sample per patient using phenol auramine-O-fluorescence staining and an immuno-fluorescent assay with monoclonal antibodies against Cryptosporidium, seropositivity for HIV and AIDS.

RESULTS

In 22% of the patients with diarrhoea an infection with C. parvum or I. belli was found. Thirteen (11%) of them had a C. parvum and 14 (12%) an I. belli infection; a mixed infection was found in one patient. In the control group, three (3%) C. parvum and three (3%) I. belli infections were seen. The prevalence of both infections was very significantly higher in the cohort of diarrhoea patients than in the controls, 13/108 versus 3/119 (p=0.0099) for C. parvum, and 14/107 versus 3/119 (p=0.0056) for I. belli. Infections were only seen in HIV positive patients. Two hundred and four (84%) patients were HIV positive and 145 (60%) of them had AIDS.

CONCLUSIONS

C. parvum and I. belli infections are a significant cause of diarrhoea among medical in-patients at QECH. Examinations of stool specimen for parasites among hospitalised patients with diarrhoea provide data for a more appropriate management.