Association between serological salmonella monitoring in breeding herds and meat-juice prevalence in sow herds with production of finishers

Several epidemiological studies have studied risk factors for salmonella infections in finisher pigs. Most of these studies have focused on the risk for having a high prevalence, measured either bacteriologically or serologically. Surveillance programs have been implemented in several European countries, measuring the salmonella prevalence in meat-juice samples. The rationale is that herds should decrease the salmonella prevalence by instituting salmonella reducing production and management strategies, including hygiene, all in-all out production and manipulating the gut flora by the use of organic acids, fermented liquid feed and coarse ground, non-pelleted feed

Human health implications of MRSA CC398 in Denmark

Methicillin-resistant Staphylococcus Aureus CC-398 (MRSA CC398) was first isolated from humans in Denmark in 2003 and from pigs in 2006 (anonymous, 2007-2015). Since then it has spread in the pig population, and a screening from 2016 found MRSA CC398 in 88 % of the screened slaughter pig herds, indicating that the majority of Danish pig herds are positive

Pork and the number of human multi-resistant Salmonella Typhimurium DT104 cases

As part of a revision of the Danish Salmonella policy, we estimated the impact of nationally produced pork compared to imported pork on the number of human sporadic domestic cases of multi-resistant Salmonella Typhimurium DT104 (MRDT104) in Denmark. We also estimated the number of deaths related to the presumed excess mortality associated with MRDT104. Data on exposure from domestic and imported pork were built into a simple simulation model in @Risk, and Monte Carlo simulations were used. Our results showed that imported pork resulted in 20 times as many human cases as domestic (2 human cases per year), and 1 extra death in 50 years. If the prevalence of MRDT104 in domestic pork increased 5 times, the absolute number of human cases (related to Danish pork) would be 8-11. The excess mortality due to this rise in human cases will be negligible compared to the mortality caused by other Salmonellae

A sudden increase in salmonella—how the surveillance system reacted: a Danish experience

Denmark has had a serological surveillance of finisher herds since January 1995, and the current surveillance of Salmonella on carcasses has been in place since 2001. Both surveillances are parts of the Danish Action Plan for Salmonella in pigs and pork. Variations in the Salmonella prevalence are evaluated, and if a variation is exceptional, much effort is done to try to find the reason for the variation, to correct it and to learn from it

Salmonella serotype distribution in Danish swine herds and pork 1998 - 2004

The serotype in the Danish swine population and in pork has been remarkable stable during the period 1998-2004. S. Typhimurium remains the predominant serotype in the entire swine population and in pork

Monitoring changes in association between salmonella-serology and microbiology over time

We found a strong correlation between seroprevalence in finishing herds and the number of positive pen samples in pig herds in level 2 or 3 in the Danish Salmonella Surveillance program. Several times during the period we observed, that the association, although always present, changed from one month to the following month. We found indications of a seasonality in the association, indicating, that late winter we would isolate more Salmonella for a given seroprevalence compared to late summer. Herds using home-mixed meal feed had less positive pen faecal samples for a given seroprevalence than herds using pelleted, purchased feed

Herd and pig-level risk factors for salmonella-seropositivity in pigs

This study reanalyses data using a new analytical approach, taking into account, that some risk-factors will increase the risk for a herd to be positive, whereas other risk factors tend to increase the risk of a high prevalence in positive herds. The zero-inflated model showed that use of pelleted feed increased the risk of being positive for the herd. In positive herds, use of pelleted feed, dry feed, increasing herd size and conventional (non-SPF) health status increased the prevalence

Sensitivity of cultivation of Salmonella enterica in pooled samples of pig faeces

We aimed investigate if the cost of bacteriological examination at herd level could be reduced by cutting down on the number of analyses without loss of sensitivity. Faeces samples sent to the lab for bacteriological examination were analysed by both the standard procedure (20 pen samples) and by mixing the same 20 samples into 10, 5 or 1 pooled sample(s), respectively. The relative sensitivity of the bacteriological analysis decreased to 94% following pooling from 20 into 10; to 92% by pooling from 20 into 5; and to 73% following pooling from 20 into 1. Percent agreement between the standard procedure and pooled samples was \u3e90% if only Salmonella-negative samples, or only Salmonella-positive samples, were pooled. Agreement was \u3e60% for pools of originally negative and positive samples. The suggested alternative pooling methods should be carried out in the laboratory

Risk-mitigation for antimicrobial resistance in Danish swine herds at a national level

In Denmark, actions to mitigate the risk related to antimicrobial resistance have been put in place continuously. Due to an increase in the consumption of antimicrobials in the Danish pig production further actions were implemented in July 2010. These were: a voluntary ban on use of cephalosporin in Danish swine herds for a 2-year period and a so-called “Yellow card” scheme from the Danish Veterinary and Food Administration (DVFA). Farmers with the highest use of antibiotics receive a Yellow Card. Approximately 10% of Danish herds are above the yellow card threshold value. The consumption in pigs is evaluated as animal daily doses (ADD) per 100 animals seen over the last 9 months (by age group)