Cyclospora cayetanensis: a review, focusing on some of the remaining questions about cyclosporiasis.

Cyclosporiasis is a protracted, relapsing gastroenteritis and has a short recorded history. Cyclospora cayetanensis is an enigmatic parasite since its discovery highlights the need for isolation of cases of infection that could be part of widespread outbreaks. It is associated with diarrhoea among children in developing countries in the Americas, where C. cayetanensis is endemic; traveller's diarrhoea and/or food and waterborne outbreaks sometimes occur in the developed countries. In SubSaharan Africa and Egypt, cyclosporiasis has been reported to occur in both immunocompromised and immunocompetent patients. Zoonotic species of Cyclospora have also been identified worldwide in primates, indicating likely endemicity of this underreported disease. This can be attributed to the lack of awareness in the public and medical profession concerning the disease, which is, therefore, not routinely tested at the health centres. The correlation between the density of water contamination and the prevalence of cyclosporiasis among the individuals of each area is significant. No doubt, water is the main vehicle of transmission in the present community. Soil contact and poultry are significant risk factors. All literature on C. cayetanensis, cyclosporiasis worldwide, and endemic cyclosporiasis was searched from libraries, colleagues and internet. Although cyclosporiasis is considered an enigma worth unravelling, with many aspects of this disease and its transmission having been uncovered only recently, the situation has been rapidly changing since the disease first came to medical attention in the 1970s.