Cross‐sectional study of faecal shedding ofGiardia duodenalisandCryptosporidium parvumamong packstock in the Sierra Nevada Range

Publisher Website
Google Scholar
Abstract
Summary: Faecal specimens from 305 horses and mules used as packstock at one of 17 commercial or governmental (National Park Service, US Forest Service) operations were examined forGiardia duodenalisandCryptosporidium parvumusing immunofluorescent microscopy. Fourteen packstock (4.6%) were sheddingG. duodenaliscysts, with herd‐level prevalences ranging 0–22%. Number of packstock in the corral, size of corral and density of packstock in the corral were associated with the odds of sheddingG. duodenaliscysts. None of the horses had detectableC. parvumoocysts. Assuming a sensitivity of at least 43% and a specificity of 100% for our assay, the estimated maximum true prevalence of shedding ofC. parvumfor packstock would be ≤ 2.3% of the population. These data suggest that faecal dispersal ofC. parvumon back country watersheds is unlikely with packstock.