The small contamination rate of broiler meat in Latvia could partly explain the lower number of Campylobacter infections in the country, according to a study.

Researchers analyzed data of Campylobacter microbiological monitoring and antimicrobial resistance (AMR) in 2008 and from 2014 to 2016. Data from broilers, poultry, pigs, calves, and humans were used to determine prevalence.

Latvia has one of the lowest rates of campylobacteriosis in the European unio (EU) with 4.6 cases per 100,000 inhabitants in 2016, however, it is likely most infections are not reported. Prevalence of Campylobacter in other Baltic countries is 22.6 and 42.4 cases per 100,000 inhabitants in Estonia and Lithuania.

The main source of human infection is contaminated fresh meat, particularly poultry due to its high consumption and milk products.

Lower than the EU average

Campylobacter prevalence was 50.2 percent in broilers, with Campylobacter jejuni the predominant species. The proportion of positive cases in fresh broiler meat was lower than the EU average in 2016, based on data from 14 countries.

Researchers collected data from the same two broiler slaughterhouses in 2008, 2014 and 2016. They found the lowest prevalence in 2008 and highest in 2014, suggesting there is not an overall tendency but various factors can affect Campylobacter contamination in broiler flocks.

Data can serve as the starting point for deeper investigation of the broiler population to evaluate factors contributing to Campylobacter infection, according to the study published in the journal Eurosurveillance.

Campylobacter prevalence was 83.3 percent in pigs, 16.1 percent in calves and 5.3 percent in humans. In pigs, Campylobacter coli was the main species. Prevalence in livestock is high, especially in pigs and broilers but levels in poultry and humans were lower than other European countries.

Animal and food samples were collected and tested within the Latvian national monitoring program for Campylobacter.

Between 2008 and 2016, the presence of Campylobacter spp. was tested in 1,303 samples, with 434 found to be positive.

For samples from broilers, 255 (50.6 percent) were positive for the pathogen. Campylobacter jejuni was detected in 95.7 percent of all Campylobacter isolates while Campylobacter coli was found in some samples in 2008.

Use of WGS

Poultry samples from retail had lower prevalence versus broilers from slaughterhouses: 12.9 percent versus three years pooled prevalence of 50.6 percent and only Campylobacter jejuni was detected.

The highest prevalence was in pigs, 114 of 127 isolates contained Campylobacter coli and 11 Campylobacter lanienae.

Human fecal samples had the lowest prevalence at 5.3 percent. Of 23 positive cases, 22 contained Campylobacter jejuni.

Whole-genome sequencing data analysis was used to characterize the diversity of Campylobacter populations from various sources and to study the correlation between sources and genotype.

Evidence from WGS can be used to confirm that systematic contamination happened in the food production chain.

“Our findings demonstrate the importance of rigorous surveillance for Campylobacter contamination within the food manufacturing chains, using standardized analytical procedures and regular data sharing between at least the neighboring countries,” said researchers.