Prevalence of exposure to Salmonella spp in finishing swine marketed in Iowa.
OBJECTIVE
To describe the prevalence of antibodies against Salmonella spp in swine marketed in Iowa.


METHODS
Swine marketed by 1,044 low-volume producers and 45 high-volume producers.


METHODS
Samples of diaphragm muscle collected from swine carcasses were tested by an indirect ELISA based on lipopolysaccharides from Salmonella spp, in particular Salmonella serovar Typhimurium. Prevalence of positive results for antibodies against Salmonella spp for carcasses, lots, and swine for each producer was determined. Producer-level seroprevalence was used to classify swine from producers as having negligible, low, moderate, or widespread evidence of previous or historical exposure to Salmonella spp.


RESULTS
From low-volume producers, 23,609 of 25,478 (92.7%; 95% confidence interval [CI], 92.4% to 92.9%) samples had negative results, and 1,863 (7.3%; 95% CI, 7.05% to 7.56%) had antibodies against Salmonella spp. Of the 6,299 lots of swine tested, 1,191 (18.9%) contained at least 1 sample with positive results. From high-volume producers, 203 of 2,486 (8.1%; 95% CI, 6.8% to 9.3%) samples had antibodies against Salmonella spp, and 124 of 629 lots had at least 1 sample with positive results for antibodies against Salmonella spp.


CONCLUSIONS
Less than 10% of pigs marketed in Iowa are apparently exposed to Salmonella spp. Most swine marketed by low-volume producers had negligible or little evidence of exposure to Salmonella spp, whereas a higher percentage of swine marketed by high-volume producers had positive results when tested to detect antibodies against Salmonella spp.
O'Connor
Annette M
AM
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
McKean
James D
JD
Beary
John H
JH
Brockus
Susan L
SL
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D005516:Food Microbiology; D007484:Iowa / Q000453:epidemiology; D008460:Meat; D015995:Prevalence; D012475:Salmonella / Q000145:classification / Q000276:immunology*; D012481:Salmonella Infections, Animal / Q000453:epidemiology* / Q000276:immunology*; D013552:Swine / Q000276:immunology*; D013553:Swine Diseases / Q000453:epidemiology* / Q000276:immunology* / Q000382:microbiology
D000907:Antibodies, Bacterial