While the rolling 12-month average in England was stable through 2009 at approximately one in every two samples testing antibody positive or weak positive, the percentage in Scotland has shown a slow increase from 22% to 25%. VLA continued to support the programme by agreeing to visit eligible holdings to collect samples and assess the effectiveness of Salmonella control measures, producing a report for the producer and his/her veterinary surgeon. Sixteen visits were completed during 2009, with 1,497 samples taken for Salmonella testing at VLA. There is a concern that breeding herds may be a reservoir of Salmonella for finisher units, and a small number of visits were specifically directed at holdings higher up the production chain. Of particular interest was the isolation of Salmonella Panama from two herds. This group D serovar is currently rarely reported from UK farms, having previously been isolated once in the last six years, although it was more prominent previously.
There were 182 incidents of Salmonella in 2009, which is similar to 2008 (183 incidents), but there were subtle changes in the prominence of minor serovars. Salmonella Typhimurium remained the most commonly found serovar. It was detected in 129 incidents in 2009, the highest number since 2003. In terms of its animal and human health implications, Salmonella 4,5,12:i:- is considered to be an important variant of S. Typhimurium and was responsible for two significant outbreaks in humans in Luxembourg. Its relative contribution has risen steadily since 2005 and was the second most common serovar isolated in 2009 (12 incidents; 6.6% of the total). Salmonella Derby was the third most common serovar in 2009, though its relative contribution was less than a third of the level observed in 2005. Fewer than half as many incidents of S. Reading and S. London were detected in 2009 compared with 2008, while S. Rissen, a serovar of feed origin, absent from the tables before
2008, contributed seven incidents in 2009.