Campylobacter infection is more often of domestic origin in Finland than previously thought, according to scientists.

To identify sources for domestic Campylobacter infections, researchers analyzed patient data from the Finnish Infectious Disease Register (FIDR) in 2004 to 2021 and outbreak data from the National Food- and Waterborne Outbreak Register (FWO Register) in 2010 to 2021. They also conducted a case-control study involving 256 patients and 756 controls with source attribution and patient sample analysis using whole-genome sequencing (WGS) in July and August 2022. 

To target control measures, more detailed information on the sources of Campylobacter infection in Finland is needed, according to the study published in the journal Microorganisms.

Sequencing could improve outbreak detection
In total, 71,716 campylobacteriosis cases were reported to the FIDR during 2004 to 2021, of which 17 percent were domestic, 42 percent were travel-related, and 41 percent were of an unknown origin. Campylobacter jejuni caused the most infections, followed by Campylobacter coli.

Of the domestic patients, 12 died within 30 days of being tested. They ranged in age from 22 to 94. Most travel-related infections originated in Thailand, Spain, and Turkey.

From 2010 to 2021, 31 foodborne and six waterborne outbreaks were reported. In the foodborne outbreaks, 276 people fell ill. Ten were caused by poultry meat such as chicken, duck breast, and pigeon and four by unpasteurized, raw milk.

In the case-control study, more than half of patients with an unknown travel history in the FIDR reported not going abroad. Scientists estimated that two-fifths of all patients could be domestically acquired, indicating that more cases than previously considered, are of domestic origin. They said to identify domestic cases, travel information should be included in the FIDR notification.

Researchers identified 22 clusters and three larger ones had seven to nine cases. None of these clusters were reported to the FWO Register, indicating that many smaller, widespread, or prolonged Campylobacter outbreaks go undetected.

“To improve outbreak detection, we recommend that all domestic Campylobacter patient isolates should be sequenced,” said scientists.

Poultry, especially broiler meat, is an important source of campylobacteriosis in Finland. More extensive sampling and comparison of patient, food, animal, and environmental isolates is needed to estimate the significance of other sources.

Situation in Colombia and Italy
Another study, published in the journal Heliyon, has looked at the prevalence and risk factors of Campylobacter in chicken in Colombia.

Ninety-one samples of fresh chicken carcasses were collected from farmers’ markets and small food stores at seven localities in Bogotá in 2021. Forty-two were positive for Campylobacter.

A higher recovery rate was obtained samples from small stores and Campylobacter jejuni was more predominant than Campylobacter coli among isolates from retail chicken.

Risk factors included poor cleanliness of scales, low frequency of disinfection of utensils, type of establishment, and direct contact of chickens with other food.

“It is important to highlight the need to carry out more studies to determine the general prevalence of Campylobacter spp. in chicken meat intended for human consumption in the country…which will allow the regulatory authorities to establish the necessary measures to reduce a possible impact of this pathogen on public health and also to generate education among consumers for the proper handling and preparation of this food at home,” said researchers.

A separate study provided epidemiological and microbiological data on Campylobacter infections in Italy during 2017 to 2021. Findings were published in the European Journal of Clinical Microbiology and Infectious Diseases.

Data was collected from 19 hospitals in 13 Italian regions. In total, 5,419 isolations of Campylobacter were performed. The most common species was Campylobacter jejuni.

Scientists tested 4,627 isolates for antimicrobial susceptibility. Over the study period, resistance to ciprofloxacin and tetracyclines decreased, while resistance to macrolides remained stable. Resistance to ciprofloxacin and tetracyclines was 75.5 percent and 54.8 percent, respectively. 50 percent of Campylobacter jejuni and coli were resistant to more than two antibiotics. 

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