Human infection with Cyclospora

Abstract

A newly-described organism, first described as a possible cause of gastrointestinal illness in humans in 1979, has since gained international recognition as a cause of prolonged diarrhoea, mainly in travellers. It was known initially as a cyanobacterium or coccidia-like body (CLB) but it has recently been proposed that the organism be named Cyclospora cayetanensis. There have been numerous reports of diarrhoea caused by C. cayetanensis in individuals who live in, or have visited, the United States, the Caribbean Islands, Central and South America, Southeast Asia, and Eastern Europe. A number of outbreaks have also been reported. Cyclospora cayetanensis is a coccidian protozoan which may be transmitted to humans via water. No animal reservoir has yet been found. The laboratory diagnosis of infection with C. cayetanensis relies upon the presence of oocysts in the faeces of infected individuals. Wet-mount light microscopy, ultraviolet autofluorescence or the modified Ziehl-Neelsen stain may be used for such detection. Many drugs have proved ineffective for the treatment of C. cayetanensis infection. However, co-trimoxazole has been shown to be effective in a limited number of cases.