Prevalence and molecular characterization of bovine Cryptosporidium from dairy cows in Northern Thailand.

Cryptosporidiosis is a common protozoan infection in humans and domestic animals. It is the culprit for significant neonatal morbidity in cattle as well as weight loss and delayed growth, which leads to large economic losses in the farming industry. Furthermore, bovine Cryptosporidium is also a principal source of human Cryptosporidium infections. The purpose of this study is to determine prevalence and genotype of Cryptosporidium spp. from feces of dairy cows from the northern parts of Thailand (Chiang Rai, Chiang Mai, and Lumpang provinces). A total of 500 fecal samples were collected directly from the rectum and they were examined for potential presence of Cryptosporidium infection by using tests such as DMSO-modified acid fast stain, immunofluorescence antibody test (IFAT) and polymerase chain reaction (PCR). The prevalence of Cryptosporidium spp. was 5% by DMSO-modified acid fast stain, 7% by IFAT and 7.6% by PCR respectively. The main genotypes of Cryptosporidium spp. identified were Cryptosporidium parvum and Cryptosporidium bovis. Therefore, as a result of this study, it can be said that, due to the potential cross-species transmission of Cryptosporidium parvum, infected dairy cows may pose a potential zoonotic risk to humans.