Eating meat fondues and raclette grill meals contributes to the annual seasonal peak of Campylobacter cases in Germany, according to a study.

During such meals, raw meat is typically handled directly at the table and touched with bare hands and often includes chicken meat, which can be contaminated with Campylobacter.

Germany recorded 46,500 cases in 2020 with the most in June to September. However, there is a recurring increase showing one peak with disease onset several days after Christmas and another peak during the New Year holidays. It is not related to travel abroad or reporting delays, according to the research.

A similar increase of Campylobacter in winter has also been seen in Switzerland and other European countries linked to meat fondue or tabletop grill meals wher meat is heated at the table.

Raw meat risks
Researchers from the Robert Koch Institute (RKI) analyzed cases notified in Germany between 2013-2014 to 2019-2020. An online survey was done among Campylobacter patients reported to local health authorities in early 2019. Reported cases served as cases or controls in the case control study, depending on date of disease onset.

Survey data from more than 400 participants who had a Campylobacter infection were evaluated. Of these people, about 180 fell ill in the seven days following the holidays. This group of case patients was compared with a group of 260 control patients who were sick at another time, according to the study published in the journal Scientific Reports.

A large proportion of participants of meat fondue meals reported they had touched the raw meat with their bare fingers, 30 percent said raw and cooked meat had been placed on the same plate, and most reported that uncooked food items, such as salads, were offered.

Less than half of people at raclette grill meals reported touching raw meat with their hands, and 15 percent said raw and cooked meat had been on the same plate. Eighty-five percent reported that foods that were uncooked, such as salads, had been available.

The association of winter peak Campylobacter with meat fondue involving chicken was slightly stronger than with raclette grill meals with chicken. One explanation may be that during fondue meals chicken is handled more than during raclette grill meals, found the study.

Researchers did not detect any trends between risk behavior, such as touching meat with bare fingers or placing raw and cooked meat on the same plate, and illness.

A sharp increase of notified Campylobacter cases with disease onset after the Christmas holidays on Dec. 27 or 28 with 70 to 136 cases per day and after the New Year’s holidays from Jan. 3 to 5 with 81 to 238 cases per day were observed each year.

The total notified cases with disease onset between Dec. 1 and Feb. 28 decreased from 7,946 in the winter season 2013/14 to 5,412 in 2018/19.

Chicken Campylobacter link and public advice
Results of the case control study confirmed the hypothesis that meat fondue or raclette grill meals consumed in the Christmas or New Year’s holidays are risk factors for Campylobacter with disease onset in late December or early January. Chicken meat was positively associated with illness after the holidays.

links were detected between fondue meals with beef or pork and Campylobacter with disease onset after the holidays. One explanation was that during these meals more than one type of meat was offered, with pork, beef and chicken as a popular combination.

Meat fondues or raclette grill meals wher turkey meat was offered were not positively associated with Campylobacter and disease after the holidays. One reason may be that turkey was the least popular meat at these meals. Also, in comparison to chicken, it is not as highly contaminated with Campylobacter, according to the study.

The Federal Institute for Risk Assessment (BfR) has published consumer tips to prevent foodborne infections with these types of meals that increase in popularity during winter.

Recommendations include good kitchen hygiene, such as separating raw meat and other items that are consumed uncooked; and thoroughly washing hands, kitchen utensils and surfaces after they have come into contact with items of animal origin and before preparation of other foods.

“To prevent Campylobacter infections after the holidays in the future, consumers should be made aware each year before the Christmas and New Year holidays about these recommendations and the infection risks they may encounter when participating in meat fondue or raclette grill meals, especially if chicken meat is offered at these meals,” said researchers.