Hot-water decontamination is an effective way of reducing risk of Salmonella in pork.

Abstract

In Denmark, pigs from herds with unacceptably high levels of Salmonella spp. (level-3 herds) are obliged to undergo slaughter under special sanitary conditions to ensure safe production. Pilot plant studies had shown that hot-water decontamination (HWD) has a significant reducing effect on E. coli (>2 log units reduction) indicating a similar effect on Salmonella spp. HWD implies that each carcass is showered with hot water (temperature 80 °C/176 °F) for 12 to 15 seconds. HWD equipment was therefore installed in one plant belonging to the largest slaughterhouse company in Denmark. Since 2001, all carcasses from high-risk herds undergo HWD. On each day of HWD, swab samples are taken from the surface of five heat-treated carcasses. These samples are analysed qualitatively as a pooled sample for Salmonella. The HWD system and present surveillance data from mid-February 2004 to December 2008 are described. The total number of pigs dealt with by HWD on a single day varied from 11 to 5,290 (median = 1,936). Salmonella was found in 2.6% of the 341 pooled samples corresponding to an individual carcass prevalence of 0.9%. This prevalence is similar to the surveillance results from pork originating from all other pigs in Denmark. Data show that HWD is an effective risk-reducing way of slaughtering pigs from herds with higher risk of Salmonella not just in a pilot plant but also during normal commercial production.