Histologic incidence and distribution of Cryptosporidium sp. infection in chickens: 68 cases in 1986.

In 1986, a retrospective examination of histologic data determined that 68 histology accessions at the Georgia Poultry Laboratories had a diagnosis of cryptosporidiosis. These cases represented 6.4% of the 1065 histologic examinations of chickens performed at the facility. Of the protozoan infections, only Eimeria sp. was diagnosed more frequently (105/1065 = 9.9%). Infected chickens came from 11 companies. Most of the cases were significantly (chi 2 = 103, df = 10, P less than 0.001) associated with two of these companies. These chickens ranged in age from 14 to 51 days. The number of cases per age group was significantly correlated (r = 0.85, t = 3.98, df = 6, P less than 0.01) with the number of cases per age group of the population of histology accessions. Additionally, cases of cryptosporidiosis had a significantly (P less than 0.05) uneven temporal distribution in that few cases were diagnosed during the winter.