[Natural Cryptosporidium sp. infection in broiler chickens in Morocco]

The prevalence of cryptosporidium infection was assessed in 38 broiler flocks. Two-hundred-and-twenty-five broilers were subjected to clinical and post-mortem examinations. Analyses of impression smears and tissue samples from the intestine, bursa of Fabricius and trachea revealed Cryptosporidium sp. in 37% of broiler flocks investigated. The prevalence of infection within flocks varied from 14 to 100%. High incidence of Cryptosporidium infection occurred in 36 to 45-day-old broilers (52%), but Cryptosporidium was not found in chickens under 25 days of age. Cryptosporidium sp. was detected in 24% of bursa examined, intestine (15%) and trachea (2%). In the bursa of Fabricius, Cryptosporidium-induced epithelial lesions were associated in most cases (94%) with lymphoid atrophy and depletion.