Prevalence of subclinical Salmonella enterica infection in Danish finishing pig herds.

Our aim was to determine the Salmonella enterica prevalence in 96 randomly selected Danish pig herds, based on serological examination of blood samples and bacteriological examination of faecal samples (collected simultaneously from the same pens). For comparison, 39 high-seroprevalence herds were included in the study. The representativeness of the selected herds was assessed, based on descriptive statistics of herd size and type. Totals of 1330 pen samples and 6814 blood samples were examined.The results from the meat-juice screening in the Danish S. enterica Control Programme were available for 3372 meat-juice samples from 91 of the 96 randomly selected herds and 1195 meat-juice samples from 37 of the 39 high-seroprevalence herds. Of the 96 randomly selected herds, 23 herds had no positive pen samples (out of 10), no positive blood samples (out of 50) and no positive meat-juice samples (out of approximately 30-40 samples in 6 months). Ten herds had one or more positive meat-juice samples but were otherwise negative. S. Typhimurium was isolated from 30 of the 39 high-seroprevalence herds. Our conclusions were: (1) The within-herd seroprevalence among the 96 randomly selected Danish pig herds was low (average within-herd seroprevalence=2%, maximum=32%). (2) Among the 39 high-seroprevalence herds (recently assigned level 3 in the S. enterica Control Programme), S. enterica was isolated from 77% of the herds when 10 pen samples were examined bacteriologically. (3) Seropositivity tended to be related to the presence of S. Typhimurium.

[1]  M. Rudemo,et al.  Multiple change-point analysis applied to the monitoring of Salmonella prevalence in Danish pigs and pork. , 1998, Preventive veterinary medicine.

[2]  F. Bager,et al.  Use of Muscle Fluid as a Source of Antibodies for Serologic Detection of Salmonella Infection in Slaughter Pig Herds , 1998, Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc.

[3]  J. Nielsen,et al.  Nation-wide Salmonella enterica surveillance and control in Danish slaughter swine herds. , 1997, Preventive veterinary medicine.

[4]  P. R. Edwards.  SALMONELLA AND SALMONELLOSIS , 1956, Annals of the New York Academy of Sciences.

[5]  D. Baggesen,et al.  The serological response to Salmonella serovars typhimurium and infantis in experimentally infected pigs. The time course followed with an indirect anti-LPS ELISA and bacteriological examinations. , 1995, Veterinary microbiology.

[6]  Jette Christensen,et al.  Herd prevalence of Salmonella enterica infections in Danish slaughter pigs determined by microbiological testing , 1996 .

[7]  J. Christensen,et al.  Salmonella level of Danish swine herds based on serological examination of meat-juice samples and Salmonella occurrence measured by bacteriological follow-up. , 1999, Preventive veterinary medicine.

[8]  H C Wegener,et al.  Phage Types of Salmonella enterica ssp. enterica serovar Typhimurium Isolated from Production Animals and Humans i Denmark , 1994, Acta Veterinaria Scandinavica.

[9]  C. Blyth.  Approximate Binomial Confidence Limits , 1986 .

[10]  H. Morgenstern,et al.  Epidemiologic Research: Principles and Quantitative Methods. , 1983 .