Lowest number of salmonella cases in 30 years, but campylobacter remains high

Salmonella Enteritidis, which was previously the most common salmonella type, is now rare in Denmark. Previously, this type was found in Danish eggs and chickens, but it has now been nearly eradicated from Danish food production. Nevertheless, the other common salmonella type, Salmonella Typhimurium, and its monophasic variant are still seen frequently in Danish food products. Unusually, we only recorded few outbreaks of salmonella in 2014 and nearly none in 2015.

In contrast hereto, many Danes still fall victim to campylobacter infections. Last year, more than 4,300 cases were recorded; this constitutes an increase with respect to previous years. The increase should, however, be seen on the basis of the facts that new methods for the detection of campylobacter have been introduced and that the information can now be drawn automatically from the laboratories – both of which have contributed to registration of more patients; and the real infection pressure is probably largely unchanged.

For a number of years, the campylobacter bacterium has caused more intestinal infections than any other bacteria – a situation that is seen also in the remaining European countries. In Denmark, approx. 4 times as many fall ill due to campylobacter as to salmonella. About a third of these patients are infected abroad. It is still not fully established how many sources of infection there are, or how we may put a stop to campylobacter infections. Several research project to enhance our understanding of this issue are currently ongoing in Denmark. However, there is consensus that the primary source of infection is chicken meat, and observing the classic kitchen hygiene precautions has considerable effect in the individual kitchens. In particular, caution is warranted when handling raw chicken meat – a few drops of raw meat juice that accidentally end up in a green salad, for example, may be sufficient to cause a campylobacter infection.

For further information, please see this week’s issue of EPI-NEWS 11/2016 which also includes reports on last year’s infections with the intestinal bacteria Yersinia enterocolitica.