Weather correlates ofCampylobacterprevalence in broilers at slaughter under tropical conditions in Sri Lanka

Abstract

AbstractCampylobacteris the primary agent of human bacterial gastroenteritis worldwide. In contrast to temperate zones, weather effects onCampylobacterprevalence in broilers under tropical conditions are under-researched. We examined the association between weather andCampylobacterprevalence in slaughtered broilers in Sri Lanka, a tropical country with weather variations led by monsoons. Each month (October 2009–July 2011), 20–30 broiler batches referring to two semi-automated slaughterhouses from five Sri Lankan provinces were tested forCampylobactercontamination and analysed in relation to temperature, humidity and rainfall. Overall prevalence was 63.8% (95% CI 59.6–67.9%,n= 542), peaking in September–November. Each 1 °C increase in monthly mean temperature up to 26 °C increasedCampylobacter-positive batches by 16.4% (95% CI 0.4–35.1%). For each 10 mm increase in monthly total rainfall up to 300 mm,Campylobacter-positive batches increased significantly by 0.8% (0.1–1.5%) at 1-month lag. For each 1% increase in relative humidity up to 80% at 1- and 2-month lags,Campylobacter-positive batches increased of respectively 4.2% (1.9–6.7%) and 4.0% (1.5–6.5), and decreased by 3.6% (2.6–4.6%) and 4.0% (2.6–5.4%) for unit increases above 80%. These results suggest that even in tropical countries without marked seasons, there are weather effects possibly reflectingCampylobacterpotential to colonise its preferred host and/or survive in the environment.