Salmonella enterica Serotype enteritidis in Table Egg Layer House Environments and in Mice in U.S. Layer Houses and Associated Risk Factors

Abstract

Prevalence was estimated for Salmonella enterica serotype eneritidis (SE) in layer house environments (n = 200 layer houses) and house mice (n = 129 layer houses) in 15 states throughout the United States. Environmental swabs were collected from manure, egg belts, elevators, and walkways. Live-catch rodent traps were placed for 4-7 days. Swabs and house mice were submitted to the laboratory for bacterial culture. Overall, 7.1% of layer houses and 3.7% of mice were culture positive for SE. The highest prevalence was in the Great Lakes region of the United States, and no SE was recovered from houses or mice in the southeast region. Presence of SE in layer houses was associated with age/molting, floor reared pullets, and number of rodents trapped. Cleaning and disinfecting houses between flocks was associated with a reduced risk. The prevalence of SE in mice from environmentally positive houses was nearly four times that of mice from environmentally negative houses.

Salmonella in Belgian laying hens: An identification of risk factors

“…24 At last, other risk factors which were not considered in the present study are important to 1 mention. For example, it could be useful to build a model taking into account flock 2 characteristics (type of breed, number of flocks on the farm, multi-age farm or not), farm 3 management (control of pest access, visitors allowed or not, feed composition and feeding 4 practices, drinking water), cleaning and disinfecting practices related with the contamination 5 status of the previous flock in the same hen house ( ( Henzler & Opitz, 1992;Kinde et al, 6 1996;Shirota et al, 2000;Garber et al, 2003;Liebana et al, 2003;Kinde et al, 2005). 7…”

Emergence of Salmonella epidemics: The problems related to Salmonella enterica serotyp Enteritidis and multiple antibiotic resistance in other major serotypes

“…There is a correlation between the presence of Salmonella in mice and the contamination of poultry. Moreover, some recent reports have shown that several wildlife species, especially rodents, are involved in the maintenance of S. Enteritidis infection on farms [38,52,86]. It is unlikely, however, that there is a causal link between the use of S. Enteritidis as rodenticide and the human cases reported since 1960 [61,129].…”

Scientific Opinion on the public health risks of table eggs due to deterioration and development of pathogens

“…Several epidemiological studies have been published, among them observational studies aiming to identify risk factors for introduction of Salmonella in laying hen flocks. Risk factors concerning flock characteristics were flock size (Mollenhorst et al, 2005;EFSA, 2007b;Namata et al, 2008;Huneau-Salaun et al, 2009), and flock age (Garber et al, 2003;EFSA, 2007b;Namata et al, 2008). The size of the farm is also linked with hygiene practices, as large farms are more likely to be dry cleaned only, rather than washed and disinfected, between flocks (Aimey et al, 2013).…”

“…Also, farm management and type of housing were identified as risk factors. Both on-floor systems (Garber et al, 2003;Mollenhorst et al, 2005) and cage systems (EFSA, 2007b;Namata et al, 2008;Gast et al, 2013) were found to increase the risk of colonization of flocks by Salmonella or of egg contamination by these or other bacteria (De Reu et al, 2009;Jones et al, 2012), including Campylobacter (Messelhäusser et al, 2011), in different studies, or to have no influence in others. These contrasting findings are likely to relate to national variations in housing systems, management and sources of birds, but, in general, cage production has been found to be associated with an increased risk of flock infections by Salmonella, and non-cage systems result in dirtier eggs, which are more likely to be contaminated by pathogens if the flock is infected (Holt et al, 2010).…”

“…Other factors were the occurrence of Salmonella in the previous flock in floor-housed flocks (HuneauSalaun et al, 2009), the absence of cleaning and disinfection of the poultry house between subsequent production cycles (Garber et al, 2003) and entry of delivery trucks near the poultry house entrance ). In addition, it appeared that seasonality was associated with serotypes other than S. Enteritidis and S. Typhimurium (EFSA, 2006).…”