is a coocidian parasite that infects a wide range of vertebrate hosts including man. The parasite is now of potential significance from both clinical and public health perspectives in that it causes severe diarrhoea in immunocompromised individuals and can be transmitted from livestock to man. This paper critically examines all the published evidence of cryptosporidium
infection in man and animal in Nigeria, in order to ascertain the presence of the zoonosis cycle of the disease. There were ten publications on the prevalence of cryptospodiosis in human patients between 1987 and 2008 in Nigeria, while there yet to be a single evidence of the presence of the disease in animals. All the studies neither identified nor characterized the species of cryptosporidium
in their findings and none of the published data examined the possibility of animals being the source of the infection to humans. The limitation of the published studies and the implication of the findings are discussed in this review.