Submitted to: Society of Protozoologists International Workshop on Opportunistic Protists
Publication Type: Abstract Only
Publication Acceptance Date: April 18, 2008
Publication Date: May 28, 2008
Citation: Santin, M., Fayer, R. Infectivity of the cervine genotype of Cryptosporidium. Society of Protozoologist X International Workshop on Opportunistic Protists (IWOP-10), May 28-31, 2008, Boston, MA. Technical Abstract: Cryptosporidiosis is a diarrheal disease of humans and animals caused by parasites in the genus Cryptosporidium, a genus comprising 19 valid species and 40 genotypes. Most human infections are caused by C. hominis and C. parvum. To a lesser extent infections with C. meleagridis, C. felis, C. canis, C. suis, C. muris, and the Cryptosporidium cervine genotype, a C. suis-like genotype, a C. andersoni-like genotype, the chipmunk genotype I, the skunk genotype and the C. hominis monkey genotype have been reported for immunocompetent and immunocomprised humans. Of these genotypes, the cervine genotype has been detected in feces from humans in Canada, New Zealand, England, and Slovenia and in more animals and over a greater geographic range than the others. It has been found in feces from wild rodents including squirrels, chipmunks, and a woochuck, beaver, deer mouse, and from a raccoon. It has been found in feces from captive lemurs as well as wild and domesticated ruminants including white-tailed deer, a blesbok, a mouflon, a Nyala, an ibex and domesticated sheep. It has been identified in storm water, watersheds, and in sewage effluent. On successive years a flock of sheep in Maryland have shown intragenotypic variations in the 18S rDNA gene for the Cryptosporidium cervine genotype. Four sequences have now been identified, 3 found in the sheep and identified as cervine 1, 2, and 3 and one identified in storm waters in New York. Parasites with a sequence identical to Cryptosporidium cervine 2 and another differing only by one A-to-G substitution were reported in humans in New Zealand. The zoonotic potential of the other intragenotypic isolates is not known. Because the cervine genotype has such a wide host range and has been found worldwide it has the potential to emerge as an important zoonotic pathogen. The continued genetic identification of cervine genotype isolates, including intragenotypic variations, as well as other isolates of Cryptosporidium found in clinical and epidemiological specimens, is important to our gaining a better understanding of the sources of these parasites and their public health significance.