Spatial distribution of Salmonella enterica in poultry shed environments observed by intensive longitudinal environmental sampling

During a series of epidemiological studies to investigate the transmission of salmonellae within poultry environments, intensive longitudinal sampling within caged sheds revealed that both the number and location of sample collection within this environment were important to ensure the best chance of detecting Salmonella spp. Multiple serovars of Salmonella enterica subspecies enterica were detected in each shed; 5% of all samples contained more than one serovar. Samples collected on the north side of the shed (OR =1.77, 95% CI [1.17, 2.68]), on the sheltered side of the shed (OR = 1.90, 95% CI [1.26, 2.89]) and during winter (OR = 48.41, 95%CI [23.56, 104.19]) were more likely to be positive for salmonellae. The distribution of salmonellae within a shed was not homogenous, as differences were identified in the within-shed distribution of Salmonella enterica subspecies enterica serovar Typhimurium (c 2 (27, 1,538) = 54.4, P 2 (27, 1,538) = 79.8, P