Cryptosporidium Infection in Sheep and Goats in Southern Botswana and Its Public Health Significance

Fecal samples of 166 sheep and 222 goats collected from 14 farms in southern Botswana were screened for the presence of Cryptosporidium infection using enzyme-linked immunosorbent assay (ELISA) and Modified Ziehl-Neelsen (MZN) staining technique. An overall prevalence rate of 13.3% (22/166) in sheep and 12.2% (27/222) in goats were detected. ELISA proved to be more sensitive in detecting Cryptosporidium infection than MZN (P = 0.04).  Lambs and goat kids aged ≤ 4 weeks showed highest infection rates of 19.4% (13/67) and 16.5% (15/91), respectively. The infection rate of 16.7% (42/251) was recorded in small ruminants ≤ 12 weeks compared to 5.1% (7/137) in adults (P = 0.002). Diarrheic animals demonstrated 20.7% (12/58) prevalence in comparison to 11.2% (37/330) in animals excreting normal solid feces (P = 0.07). The significance levels in the infection rates in sheep versus goats and males versus females were P =0.87 and P = 0.76, respectively. Animals reared under traditional communal management system exhibited more susceptibility to cryptosporidiosis than those under semi-intensive husbandry system (P = 0.04). Of the 62 environmental samples taken, Cryptosporidium oocysts were detected in 2 of 27 (7.4%) soil and 1 of 22 (4.5%) water samples. None of 14 manure specimens derived from every sampled small stock farm was found positive. The results of the present study revealed the occurrence of Cryptosporidium infection in small stock population in southern Botswana. It suggested potential role of young lambs and goat kids for transmission of human cryptosporidiosis via environmental contamination. Application of molecular techniques for characterization of Cryptosporidium field isolates including zoonotic species and genotypes is urgently required. Creation of farmers’ awareness through extension education program on good animal husbandry practices will help in devising appropriate strategies to control animal and human cryptosporidiosis.