Estimation of the Salmonella enterica prevalence in finishing swine.
The study objective was to evaluate three methods of Salmonella enterica prevalence estimation in swine herds (faecal culture, culture of abattoir-collected samples, and serum ELISA). From each of six swine herds, we necropsied approximately 100 finishing pigs (> 70 kg); one-half on farm and the other half at the abattoir, after transport and approximately 2.5 h holding. We collected the same samples for S. enterica culture at both locations (1 g faecal, 10 g caecal contents, ileocaecal lymph nodes, superficial inguinal lymph nodes, 25 g of gluteal muscle for serum ELISA). On farm, the 1 g faecal sample only detected 13.3% (2/15) of all positive pigs necropsied on farm. However, with abattoir and on-farm results combined, the faecal sample detected 57.4% (74/129) of positive pigs. Abattoir-collected samples provided prevalence estimates much higher than on-farm collected samples (39.9 vs. 5.3%; P < 0.001). This study shows that faecal samples have a low sensitivity for detecting infected pigs and that abattoir-collected samples overestimate the on-farm S. enterica prevalence. For most herds, serology overestimated the on-farm culture prevalence.
Hurd
H S
HS
Pre-Harvest Food Safety and Enteric Diseases Research Unit, USDA, Agricultural Research/2 Unit, Ames, IA 50010-0070, USA.
McKean
J D
JD
Griffith
R D
RD
Rostagno
M H
MH
D000003:Abattoirs; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001344:Autopsy; D015982:Bias; D002432:Cecum / Q000382:microbiology; D004797:Enzyme-Linked Immunosorbent Assay; D005243:Feces / Q000382:microbiology; D007082:Ileum / Q000382:microbiology; D008198:Lymph Nodes / Q000382:microbiology; D011159:Population Surveillance / Q000379:methods; D015995:Prevalence; D012307:Risk Factors; D012481:Salmonella Infections, Animal / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D019779:Salmonella enterica / Q000235:genetics / Q000276:immunology; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D012703:Serotyping; D013048:Specimen Handling / Q000379:methods / Q000592:standards; D013552:Swine; D013553:Swine Diseases / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology
D000907:Antibodies, Bacterial