Campylobacter prevalence in Danish finisher pigs from mixed production herds

Abstract

these media are not appropriate for detection of non-motile or less motile Salmonella bacteria. Therefore, a combination of a semi-solid medium with a liquid medium, such as RV, is recommended. Several factors were significantly associated with the presence of Salmonella spp. The increased risk associated with natural ventilation might be related to biosecurity, which is likely to be lower in naturally ventilated barns. The decreased risk associated with an age of 2-3 months compared to an age of 3-4 months might be related to one or more causes, i.e. (i) maternal immunity preventing Salmonella colonisation at a younger age, (ii) a preventive effect of medication administered at an early stage of life, or (iii) enhanced exposure to Salmonella after transportation to a finishing barn (usually around 10 weeks of age). The protective effect found for the use of fermented liquid feed is hypothetically related to the presence of organic acids in this type of feed which may inhibit the presence of Salmonella in the feed and enhance the acid barrier of the stomach (van der Wolf et al., 2001). The preventive effect found for the presence of cats on the premise might be related to the expelling of rodents, which are considered important vectors for Salmonella infection (Lo Fo Wong et al., 2002). For the other associations determined, no hypotheses could be generated.

Evaluation of diagnostic methods used in zoonosis-surveillance programs

“…Samples were analyzed according to the same bacteriological procedures as in the DANMAP surveys. The results of the screening are summarized in Table 1 (see also Boes et al, 2003, in this issue). All 247 herds were positive for Campylobacter species (herd prevalence = 100 %), and 92 % of pigs were Campylobacter positive.…”

“…Latent-class methods have been used for validation of the mix-ELISA for detection of Salmonellaspecific antibodies in meat juice (En_e et al, 2001). Crude estimates of apparent prevalences can be highly biased when compared to estimated true prevalences, potentially leading to serious underreporting (En_e et al, 2003). In the monitoring of Campylobacter in DANMAP the importance of common criteria for data collection becomes evident when prevalences of culture positive samples are compared with the results from the DBMC study.…”