8% of Finnish chicken contaminated with Campylobacter - study
In Finland, 4,000-5,000 cases of campylobacteriosis are reported annually, the majority of which are contracted abroad.
It is considerably more common in Finnish poultry meat towards the end of summer than any other time of the year.
Three enumeration results were above 10 CFU/g. The highest observed concentration was 38 CFU/g in chicken meat and 0.5 CFU/g in turkey meat.
Prevalence in meat
No Campylobacter was detected in pork and beef collected from retail stores.
“During the one year that we analysed, approximately 8% of Finnish broiler meat and approximately 3% of turkey meat tested positive for Campylobacter. The prevalence in pork and beef was estimated as very low, as no Campylobacter was detected in the almost 800 samples that we analysed,” said Antti Mikkelä, researcher from Evira’s Risk Assessment Research Unit.
Based on retail samples, the average annual prevalence of Campylobacter spp. was estimated at 5.5–11.7% (95% CI) in Finnish chicken meat and 1.8–5.9% (95% CI) in turkey meat.
“The mean concentration of Campylobacter spp. in contaminated poultry meat was estimated to be low, and the probability of illness per one serving was thus also relatively small,” according to the risk assessment.
“Even so, the assessment implies that thousands of human cases can occur due to meat consumption annually in Finland, with the biggest proportion related to chicken meat.
“However, the predicted number of cases is affected by many factors with uncertainty, such as the level of cross-contamination, size of serving and total consumption.”
The study focused on fresh Finnish meat and included almost 2,000 samples. All samples collected between 2012 and 2014 were from shops in Helsinki but represented more than 90% of all fresh Finnish meat sold across the country.
“Despite the generally relatively low levels of Campylobacter in Finnish meat, the number of bacteria thus remaining in the food can be high enough to cause food poisoning. Using pre-packaged, precut meat reduces the need to handle the meat in the kitchen, which lowers the risk of contamination,” said Marjaana Hakkinen, senior researcher from Evira’s Food and Feed Microbiology Research Unit.
Statistical model to estimate Campylobacter
The joint project of the Finnish Food Safety Authority (Evira) and the University of Helsinki also developed a statistical model.
It was used to estimate the prevalence and concentrations of Campylobacter in poultry, pork, and beef sold to consumers at retail level.
The number of living bacteria in a 150g portion of meat was estimated at 300 on average in contaminated chicken and at just 45 in turkey.
Concentrations were below the limit of determination of the microbiological method for most contaminated samples but the statistical model allowed the low concentrations to be taken into account.
“It takes account of concentrations below the limit of determination of the microbiological method, temporal variation, as well as within-batch and between-batch variations in prevalence and concentrations. Ignoring these factors leads to incorrect prevalence and concentration estimates,” said Jukka Ranta, senior researcher from the Risk Assessment Research Unit.
New Zealand testing
Meanwhile, a Consumer NZ test of 40 fresh chicken found Campylobacter in 26 samples.
Campylobacter is the leading cause of notified gastrointestinal infections in New Zealand with rates peaking over summer.
Last year, 6,218 cases were notified and rates were 135.3 per 100,000, down from 150.4 in 2014.
Sue Chetwin, Consumer NZ chief executive, said the bug’s presence in tested products doesn’t mean consumers will get sick from the chicken but it does increase the chances.
She said the research supports the case for regular testing by regulators of chicken sold in retail stores.
“Experience in the UK, where retail testing is carried out, indicates it raises public awareness of the problem and can also prompt retailers and manufacturers to reduce contamination in the supply chain.”
The Ministry for Primary Industries (MPI) has a target of reducing Campylobacter cases by 10% by 2020.
Data between January 2013 and October 2014 found there were 130 occasions where processing plants exceeded contamination limits.
