Carry-over risks in fattening units for Campylobacter spp.

There is a lack of information about the prevalence of the important zoonotic pathogens Campylobacter spp. and Yersinia spp. at different stages in the pig production chain. The aim of this study was to determine these prevalence in a total of 1 040 faecal samples and to gather further information about the sources of infection with Campylobacter spp. and their qualitative and quantitative importance in the pig production. During the slaughtering process, 122 pigs and their carcasses respectively, were sampled three times. Campylobacler spp. were isolated in sows (33.8%), piglets (80.9%), growing (89.2%) and finishing (64.7%) pigs. Yersinia spp. were detected in growing (15.2%) and finishing (13.3%) pigs only. For statistical analysis, bacteriological results for Campylobacter spp. were evaluated with questionnaire facts from four farrowing and twelve fattening units. In the production stage farrowing, a significant influence for the factors number of sows and forage store cleaning was detected by a generalized linear model. In the production stage fattening, following factors had a significant effect on the Campylobacler spp. prevalence: number of fattening places , mixed farm , sampling time , bottom , forage , antibacterial and anthelmintic prophylaxis

Practical experiences with the reduction of prevalence of Salmonella infections in pig herds

Salmonella reduction is an issue with still increasing importance for the swine production. PIC in Germany has already started with specific interventions to reduce Salmonella prevalence in their breeding herds in 2001 – just one year before the “QS Qualität und Sicherheit GmbH” began to set up the serological Salmonella monitoring in German finishing pigs

Practical experiences with the reduction of prevalence of Salmonella infections in pig herds

Salmonella reduction is an issue with still increasing importance for the swine production. PIC in Germany has already started with specific interventions to reduce Salmonella prevalence in their breeding herds in 2001 – just one year before the “QS Qualität und Sicherheit GmbH” began to set up the serological Salmonella monitoring in German finishing pigs.</p

Carry-over risks in fattening units for Campylobacter spp.

There is a lack of information about the prevalence of the important zoonotic pathogens Campylobacter spp. and Yersinia spp. at different stages in the pig production chain. The aim of this study was to determine these prevalence in a total of 1 040 faecal samples and to gather further information about the sources of infection with Campylobacter spp. and their qualitative and quantitative importance in the pig production. During the slaughtering process, 122 pigs and their carcasses respectively, were sampled three times. Campylobacler spp. were isolated in sows (33.8%), piglets (80.9%), growing (89.2%) and finishing (64.7%) pigs. Yersinia spp. were detected in growing (15.2%) and finishing (13.3%) pigs only. For statistical analysis, bacteriological results for Campylobacter spp. were evaluated with questionnaire facts from four farrowing and twelve fattening units. In the production stage farrowing, a significant influence for the factors number of sows" and "forage store cleaning" was detected by a generalized linear model. In the production stage fattening, following factors had a significant effect on the Campylobacler spp. prevalence: "number of fattening places", "mixed farm", "sampling time", "bottom", "forage", "antibacterial" and "anthelmintic prophylaxis".</p

Individual risk factors for Mycoplasma hyopneumoniae infections in suckling pigs at the age of weaning

BACKGROUND: In recent years, the occurrence and the relevance of Mycoplasma hyopneumoniae infections in suckling pigs has been examined in several studies. Whereas most of these studies were focused on sole prevalence estimation within different age groups, follow-up of infected piglets or assessment of pathological findings, none of the studies included a detailed analysis of individual and environmental risk factors. Therefore, the aim of the present study was to investigate the frequency of M. hyopneumoniae infections in suckling pigs of endemically infected herds and to identify individual risk factors potentially influencing the infection status of suckling pigs at the age of weaning. RESULTS: The animal level prevalence of M. hyopneumoniae infections in suckling pigs examined in three conventional pig breeding herds was 3.6% (41/1127) at the time of weaning. A prevalence of 1.2% was found in the same pigs at the end of their nursery period. In a multivariable Poisson regression model it was found that incidence rate ratios (IRR) for suckling pigs are significantly lower than 1 when teeth grinding was conducted (IRR: 0.10). Moreover, high temperatures in the piglet nest during the first two weeks of life (occasionally >40°C) were associated with a decrease of the probability of an infection (IRR: 0.23-0.40). Contrary, the application of PCV2 vaccines to piglets was associated with an increased infection risk (IRR: 9.72). CONCLUSIONS: Since single infected piglets are supposed to act as initiators for the transmission of this pathogen in nursery and fattening pigs, the elimination of the risk factors described in this study should help to reduce the incidence rate of M. hyopneumoniae infections and thereby might contribute to a reduced probability of high prevalences in older pigs

Estimating Diagnostic Test Accuracies for Brachyspira hyodysenteriae Accounting for the Complexities of Population Structure in Food Animals

For swine dysentery, which is caused by Brachyspira hyodysenteriae infection and is an economically important disease in intensive pig production systems worldwide, a perfect or error-free diagnostic test ("gold standard") is not available. In the absence of a gold standard, Bayesian latent class modelling is a well-established methodology for robust diagnostic test evaluation. In contrast to risk factor studies in food animals, where adjustment for within group correlations is both usual and required for good statistical practice, diagnostic test evaluation studies rarely take such clustering aspects into account, which can result in misleading results. The aim of the present study was to estimate test accuracies of a PCR originally designed for use as a confirmatory test, displaying a high diagnostic specificity, and cultural examination for B. hyodysenteriae. This estimation was conducted based on results of 239 samples from 103 herds originating from routine diagnostic sampling. Using Bayesian latent class modelling comprising of a hierarchical beta-binomial approach (which allowed prevalence across individual herds to vary as herd level random effect), robust estimates for the sensitivities of PCR and culture, as well as for the specificity of PCR, were obtained. The estimated diagnostic sensitivity of PCR (95% CI) and culture were 73.2% (62.3; 82.9) and 88.6% (74.9; 99.3), respectively. The estimated specificity of the PCR was 96.2% (90.9; 99.8). For test evaluation studies, a Bayesian latent class approach is well suited for addressing the considerable complexities of population structure in food animals