Swedish public health officials have reported an increase in the number of people infected with Campylobacter in recent weeks.

Folkhälsomyndigheten (the Public Health Agency of Sweden) said the rise is expected and is at similar levels compared to the previous year.

From the beginning of June, the number of cases increased from 30 to 70 in the week starting June 23. People have fallen sick across the country.

According to Folkhälsomyndigheten, during the summer, the risk of becoming infected with Campylobacter goes up in Sweden. Finding Campylobacter in chicken flocks is more common and there is a correlation between the prevalence in flocks and the number of people who become sick.

Improperly handled or eating undercooked chicken is a known cause of infection. Advice from Livsmedelsverket (the Swedish Food Agency) to avoid getting sick includes always washing hands with soap and water, separating raw chicken meat from other foods and always cooking chicken thoroughly. Other causes of infection are direct contact with animals, drinking unpasteurized milk or unclean water.

Similar situation in 2024
Incidence was slightly higher during the peak season of July to September 2024 plus there was a small increase in November, which Svensk Fågel attributed to a later and warmer winter than normal. Svensk Fågel is the national industry organization for poultry production. 

In 2024, 4,715 tests involving birds raised by members of Svensk Fågel were sampled at slaughter as part of the Campylobacter monitoring program. Campylobacter was detected in 6.4 percent of the flocks, which was slightly higher than 2023 levels.

A total of 70 samples were also analyzed from chickens raised and killed at slaughterhouses that are not members or affiliated with Svensk Fågel. Campylobacter was detected in 34 flocks which gave a positive rate of 48.6 percent, which was also higher than in 2023.

In 2024, there were 5,440 Campylobacter infections reported, a decrease compared to 5,675 in 2023. The incidence of cases infected in Sweden was the same as the previous year, while the proportion of people infected abroad decreased. 

Incidence was highest in the age groups 60 to 69 and 50 to 59 and was higher among men than women in most age groups. Most cases occurred in July to August. The increase in summer came after a rise in the proportion of positive findings of Campylobacter in broiler flocks.