Prevalence and risk factors for cryptosporidiosis: a global, emerging, neglected zoonosis

Background: Cryptosporidiosis is a zoonotic disease caused by the important parasitic diarrheal agent Cryptosporidium spp. Cryptosporidiosis occurs in all classes of animals and man with a rapidly expanding host range and increased importance since the occurrence of human immunodeficiency virus/acquired immunodeficiency syndrome in man. Objectives: To review the global picture of cryptosporidiosis in man and animals with emphasis on prevalence and risk factors. Methods: Current relevant literature on cryptosporidiosis was reviewed. Results: Cryptosporidiosis is widely distributed and the risk factors vary from one region to another with hygiene and immune status as important risk factors. Conclusions: Cryptosporidium spp. associated mortality has not only been reported in immune-compromised patients, but also in immune-competent patients. Yet in many countries not much attention is paid to the control and prevention of this infection in animals and man. The neglect of this disease despite the serious threat it poses to animals, their husbandry, and humans, has led the World Health Organization to list it among globally neglected diseases. To control and prevent this infection more effort needs to be directed at controlling the risk factors of the infection in man and animals.