Cryptosporidium

Systematics Success Stories

Discovery of new species of Cryptosporidium, significant water-borne pathogens of humans and food-animals and wild hosts.

Problem: Cryptosporidiosis is a waterborne disease caused by protozoan parasites of the genus Cryptosporidium. The diagnostic stage found in feces of infected humans and animals is morphologically identical for most of the 11 species of Cryptosporidium and must be differentiated by molecular methods combined with biological studies to determine the actual hosts of each species. Because 154 species of mammals have been found infected with Cryptosporidium determining the sources of infection for humans and livestock has become extremely complex.

Solution: Studies by ARS scientists Ron Fayer and Jim Trout with collaborators at the CDC, NOAA, Murdoch University (Australia) and the Johns Hopkins University have resulted in the identification and naming of two new species, Cryptosporidium canis and Cryptosporidum hominis, as well as new genotypes of Cryptosporidium parvum from mammals closely associated with surface water, including beavers, muskrats, and otters.

Impact: These findings have greatly expanded the ability of epidemiologists to detect and identify potential sources of these pathogens and when properly identified to scientifically evaluate their risk to public health and determine methods to reduce infections for humans and livestock.

(Contact- Dr. Ron Fayer, Animal Waste Pathogen Laboratory).