Infectious Diseases 2022

Infectious Diseases 2022

The Norwegian Zoonoses Report 2020

10 January, 2022

Salmonellosis: The number of reported cases of salmonellosis in humans (440) decreased in 2020 compared to the previous four years. The surveillance programme for Salmonella includes testing of live animals (pigs, poultry and cattle) and fresh meat (pigs and cattle). From altogether 8,882 faecal samples in 1,342 poultry holdings one broiler flock was positive for Salmonella, giving an estimated Salmonella prevalence of 0.02% in poultry flocks for slaughter. The number of salmonellosis cases in humans has decreased over the past 10 years. The number of cases infected in Norway has remained relatively stable with an incidence of 3.6 to 6.1 in the last 5 years (2015- 2019) but decreased to 3.2 in 2020, probably due to measurements against COVID-19 in Norway. The reduced prevalence of Salmonella in European poultry is presumed to contribute to the observed reduction.
Campylobacteriosis: 2,422 human cases of campylobacteriosis were reported in 2020. Surveillance in poultry in 2020 showed that a total of 115 flocks (6.1%) tested positive for Campylobacter spp. when all broiler flocks slaughtered before 51 days of age during the period May – October were tested. In total 1,893 flocks from 490 farms were sampled. Of all farms sampled, 86 (17.6%) had positive flocks and of these, 24 (4.9% of all farms) had two or more positive flocks. This means that almost 50% of the positive flocks originated from less than 5% of the farms. The carcasses from the positive flocks were either heat treated or frozen for a minimum of three weeks before being marketed. Caecal samples from 117 turkey flocks were examined. C. jejuni isolates were obtained from five flocks (4.3%) and C. coli from one flock (0.8%).
The prevalence of Campylobacter in broilers is low in Norway (3-7% of slaughtered flocks) compared to other countries. The measures implemented in Norway to reduce Campylobacter in chicken meat are considered to have had a positive effect on public health. A few farms seem to deliver a high proportion of the positive flocks.