Risk factors associated with Lawsonia intracellularis in English pig farms

Porcine proliferative enteropathy (PPE) caused by the bacterium Lawsonia intracellularis causes considerable economic loss to the pig industry. The objective of this study was to evaluate the seroprevalence of L. intracellularis exposure in different age groups of pigs (growers to finishers) within English farms and to identify potential risk factors. Samples were obtained in a cross-sectional study of 147 farms between 2008 and 2009. Twelve samples (six growers and six finishers) from each farm were tested for L. intracellularis by antibody ELISA. At animal level there was a significant positive linear trend between seroprevalence and age in weeks (r(2)=2.65,