Lack of Evidence That Bird Feeders Are a Source of Salmonellosis during Winter in Poland

SIMPLE SUMMARY: Bird feeders are known to be a transfer site for many important bird pathogens, such as zoonotic Salmonella spp., known to be widespread among wild birds in Poland. The aim of the study was to investigate (1) whether feeders can be a source of Salmonella spp., (2) whether the risk is the same for feeders located in cities and rural areas and (3) whether there is a different level of contamination with Salmonella spp. between old and new feeders. Data were collected in winter 2018 in Poland, and in total, 204 feeders were sampled. Material for analysis consisted of the remains of food and feces. We did not find the presence of Salmonella spp. in any of the tested samples collected from bird feeders. Reasons for the isolation of Salmonella spp. from feeders not being successful lie in the low intensity of bacterial shedding by infected wild birds and low survival of bacteria in the environment. ABSTRACT: Bird feeders are known to be a transfer site for many important bird pathogens, such as zoonotic Salmonella spp., known to be widespread among wild birds in Poland. The aim of the study was to investigate (1) whether feeders can be a source of Salmonella spp., (2) whether the risk is the same for feeders located in cities and rural areas and (3) whether there is a different level of contamination with Salmonella spp. between old and new feeders. Data were collected in the period 12 January–28 February 2018 in four cities in Poland and nearby rural areas. In total, 204 feeders were sampled. The samples from feeders were taken after a 2-week period of feeding birds. Material for analysis consisted of the remains of food and feces. We did not find the presence of Salmonella spp. in any of the tested samples collected from bird feeders. Therefore, the estimated value of the 95% confidence interval for the binary data was 0.000–0.018. Reasons for the isolation of Salmonella spp. from feeders not being successful lie in the low intensity of bacterial shedding by infected wild birds and low survival of bacteria in the environment in bird feces—which are still not well studied.