Prevalence and Concentration of Escherichia coli O157:H7 in Cattle, Products, and the Environment in the United States of America: A Meta-Analysis Study

Shiga toxin-producing Escherichia coli O157:H7 are bacterial pathogens that cause foodborne infections in humans. The objectives of this study were to find the pooled prevalence and concentration of Escherichia coli O157:H7 in cattle, hides, carcass, and the environment in the United States of America using meta-analysis. The PRISMA and MOOSE research protocols were employed in the methodology. Weighted effect size was calculated using MetaXL software. A total of 1737 publications were screened, out of which 53 were selected for the final analysis. The pooled prevalence in feedlot cattle was 10.96% (95% CI: 4.2-18.8%). In dairy cattle a pooled prevalence of 1.5% (95% CI: 0.11-3.5%) was observed. The prevalence between feedlot and dairy cattle was significantly different (p<0.05). The herd prevalence in combined feedlot and dairy cattle was 31.7% (95% CI: 10.2-55.5%). Hide and carcass samples’ pooled prevalences were 54.7% (95% CI: 41.7-67.5%) and 21.3% (95% CI: 9.7-34.2%), respectively. Prevalence of environmental samples was 8.1% for produce (95% CI: 0-29.6%), 4.6% for watershed and sediment samples (95% CI: 0-12.2%), and 2.4% for water taken from troughs (95% CI: 0.39-5.1%). Significant difference was observed in individual, herd, and environment prevalence between regions (χ2 =903.14, p=0.0000; χ2 =11.06, p=0.0039; χ2 =13.59, p=0.0004, respectively). E. coli O157:H7 concentrations were highest in feces (900- 300,000 cfu/g), followed by hides (5-9,800 cfu/100 square cm), and carcass (1-189 cfu/100 square cm). At least one supershedder exists in a herd. The findings in this study showed that Escherichia coli O157:H7 serotype is widespread in feedlots, herds, hides, and carcass in the United States of America necessitating appropriate measures to prevent human illnesses. Improving management programs in cattle herds, reduction of environmental contamination, and hygienic slaughter practices are targets of intervention.