PREVALENCE OF AND ASSOCIATED RISK-FACTORS FOR SHEDDING CRYPTOSPORIDIUM-PARVUM OOCYSTS AND GIARDIA CYSTS WITHIN FERAL PIG-POPULATIONS IN CALIFORNIA

Populations of feral pigs (Sus scrofa) may serve as an environmental r eservoir of Cryptosporidium parvum oocysts and Giardia sp, cysts for s ource water, We conducted a cross-sectional study to determine the pre valence of and associated demographic and environmental risk factors f or the shedding of C. parvum oocysts and Giardia sp, cysts. Feral pigs were either live-trapped or dispatched from 10 populations located al ong the coastal mountains of western California, and fecal samples wer e obtained for immunofluorescence detection of C. parvum oocysts and G iardia sp. cysts, We found that 12 (5.4%) and 17 (7.6%) of 221 feral p igs were shedding C. parvum oocysts and Giardia sp. cysts, respectivel y, The pig's sex and body condition and the presence of cattle were no t associated with the probability of the shedding of C. parvum oocysts , However, younger pigs (less than or equal to 8 months) and pigs from high-density populations (>2.0 feral pigs/km(2)) were significantly m ore likely to shed oocysts compared to older pigs (>8 months) and pigs from low-density populations (less than or equal to 1.9 feral pigs/km (2)), In contrast, none of these demographic and environmental variabl es were associated with the probability of the shedding of Giardia sp, cysts among feral pigs, These results suggest that given the propensi ty for feral pigs to focus their activity in riparian areas, feral pig s may serve as a source of protozoal contamination for surface water.