Treatment of isosporiasis with combined albendazole and ornidazole in patients with AIDS

Cystoisospora belli infections in humans: the past 100 years

Cystoisospora belli is a coccidian parasite of humans, with a direct fecal-oral transmission cycle. It is globally distributed, but mainly found in tropical and subtropical areas. Many cases of C. belli infections have been reported in patients with HIV, and in patients undergoing immunosuppressive therapy for organ transplants or those treated for tumours worldwide. Unsporulated or partially sporulated oocysts of C. belli are excreted in feces. When sporulated oocysts in contaminated water or food are ingested, asexual and sexual stages of C. belli are confined to the epithelium of intestines, bile ducts and gallbladder. Monozoic tissue cysts are present in extra-intestinal organs (lamina propria of the small and large intestine, lymph nodes, spleen, and liver) of immunosuppressed humans. However, a paratenic host has not been demonstrated. Cystoisospora belli infections can be persistent, lasting for months, and relapses are common; the mechanism of relapse is unknown. Recently, the endogenous stages of C. belli were re-examined and attention was drawn to cases of misidentification of non-protozoal structures in the gallbladder of patients as C. belli. Here, we review all aspects of the biology of C. belli, including morphology, endogenous stages, prevalence, epidemiology, symptoms, diagnosis and control.

Treatment of parasitic diarrhea in HIV-infected patients

Parasitic infections responsible for diarrhea have a worldwide distribution, overlapping with AIDS in most countries. Indeed, highly active antiretroviral therapy has markedly reduced the incidence of most parasitic opportunistic infections, but parasite-related diarrhea remains frequent and probably underestimated in developing countries. In this review, we focus on the advances in molecular epidemiology, diagnosis and current treatment of the most prevalent parasitic infections in HIV-infected patients. Most of these parasites are protozoa, whose diagnosis at the laboratory requires some adapted technique and expertise. We highlight the importance of diagnosis and the skill of the laboratory of parasitology, since most parasitic infections responsible for diarrhea in AIDS patients can be treated.

Recurrent isosporiasis over a decade in an immunocompetent host successfully treated with pyrimethamine

Recurrent isosporiasis in an immunocompetent host is reported. The patient suffered from chronic intermittent diarrhea for over a decade. Multiple short-term administrations of trimethoprim-sulfamethoxazole followed by pyrimethamine, or albendazole combined with tinidazole could not control the relapses. However, treatment with pyrimethamine, 25 mg/d for 20 weeks, was successful.