Prevalence, Risk Factors, and Public Health Implications of Shiga Toxin-Producing E. coli (STEC) in Dairy Cattle Herds

Abstract

To assess the global prevalence, risk factors, antimicrobial resistance (AMR), and public health significance of Shiga toxin-producing Escherichia coli (STEC) in dairy cattle herds, this systematic review identified 514 studies published from 2015 to 2025. The overall global prevalence of STEC was 28.4%. There was a strong age-dependent colonization, with calves showing a significantly higher shedding rate (42.3%) than adult cows (19.8%). On a regional level, Asia experienced the highest pooled prevalence (36.7%) and Europe the lowest (21.2%). An increasing number of non-O157 serotypes (such as O26, O103, and O111) have been replacing the traditional O157:H7 strain. The most important factors that are associated with shedding are the young age of the herd, large numbers, warmer seasons, high-concentrate feeding, and recent usage of antimicrobial agents. Worryingly, 54.3% of the isolates were resistant to at least one antimicrobial, and 28.7% were multidrug resistant. Humans can be exposed to it through contaminated dairy and direct contact or through the environment. Improved biosecurity, integrated interventions, especially vaccination, and a One Health approach are essential to reduce this global public health threat.