26 March 2016
Salmonella: Two serotypes - S. Enteritidis and S. Typhimurium - generally account for about two thirds of all salmonella infections in Denmark. The number of zoonotic salmonella cases registered in 2014 was 1,124 (19.7 per 100,000), which is nearly the same as the previous two years. In 2015, the number decreased to 925 cases, 18% less than in 2014 (16.2 per 100,000). As in previous years, patients below 5 years of age accounted for a relatively high number of diagnosed salmonella infections. This also reflects that relatively more in this age group are tested for salmonella.S. Enteritidis and S. Typhimurium and the S.T monophasic variant accounted for the majority of infections: a total of 62% of all infections in 2014 and 54% in 2015. Both in 2014 and in 2015, the monophasic variant of S. Typhimurium, including isolates with the antigen formula ”1,4,[5],12:i:-” was more frequently observed than S. Typhimurium.
In 2014, a series of clusters of infections with the same types were detected and tested. Among these clusters, 12 were considered outbreaks.The autumn of 2014 saw an outbreak counting 18 registered patients. This outbreak was caused by S. Enteritidis with a specific MLVA profile. In this latter outbreak, investigation was initiated after serious illness was established in a Danish egg-laying farm. Eggs from this farm were immediately recalled from the market and the flock culled. Nevertheless, a total of 13 persons had already fallen ill from eating eggs, while another 5 patients who fell ill had not ingested eggs from the same producer. Three of these had eaten eggs from other farms close by.
Campylobacter: In 2014, a total of 3,797 (67 per 100,000) Campylobacter spp infections were reported; nearly the same number as that recorded for the preceding year. In contrast, an increase in the number was seen in 2015, as the total registered was 4,348 (77 per 100,000) cases, corresponding to a 12% increase. The age-specific incidence shows how the disease burden is rather equally distributed across the age groups with a small excess rate among persons in their twenties, which is quite typical for campylobacter. Among the strains whose species were determined, the overall result was that approx. 93% of the strains belonged to C. jejuni and around 6% to C. coli. Campylobacter outbreaks are relatively rare. In the 2014-15 period, no water-borne outbreaks were described. In 2015, two food-borne campylobacter outbreaks were registered. One occurred in May among the employees of companies in the Copenhagen area who used a specific catering company as lunch provider. A total of 110 persons fell ill and the source of infection was not identified. The second outbreak occurred in connection with a scout camp in Jutland where 25 persons fell ill, and the investigation indicated that the source might be insufficiently roasted chickens, made over camp fires.