Risk of infection with Cryptosporidium parvum and Cryptosporidium hominis in dairy cattle in the New York City watershed.

Objective: To determine the risk posed by Cryptosporidium parvum and Cryptosporidium hominis from dairy cattle in the New York City watershed (NYCW).

Sample Population: Samples from cattle at risk for shedding Cryptosporidium organisms on randomly selected dairy farms in the NYCW.

Procedure: Feces were collected for 4 years from calves at risk for infection on 37 dairies.