Prevalence and Multiplex PCR-Based Molecular Detection of Campylobacter jejuni and Campylobacter coli in Chickens and Hand Swabs of Handlers at Live Bird Markets in Maiduguri Metropolis, Nigeria
This study reveals a high prevalence of *Campylobacter jejuni* and *Campylobacter coli* in both local chickens and the hands of handlers at live bird markets in Maiduguri, Nigeria, highlighting significant zoonotic transmission risks and the need for targeted biosecurity and molecular surveillance.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of a preprint that has not been peer-reviewed. It is not medical advice. Do not make health decisions based on this content. Read full disclaimer
In the bustling corners of live bird markets across the world, a silent exchange of microscopic life occurs between birds and the people who tend to them. At the heart of this interaction are two specific types of bacteria, Campylobacter jejuni and Campylobacter coli. These are not merely harmless residents of the chicken gut; they are the leading causes of bacterial stomach infections in humans globally. While chickens often carry these germs without showing any signs of illness, they shed them constantly, creating a potential bridge for infection to jump to people who handle the birds or eat undercooked meat. Understanding how widespread these bacteria are in specific markets, and whether they are present on the hands of the workers, is crucial for protecting public health. It is a question of tracing the invisible path from the farm to the human hand.
In the arid, sun-drenched city of Maiduguri in northeastern Nigeria, researchers set out to map this invisible landscape within the local live bird markets. They focused on six major markets where chickens are traded, slaughtered, and prepared for sale. The team collected samples from two distinct sources: the cloacal swabs of 195 chickens, representing both commercial broilers and local free-range birds, and hand swabs from 17 handlers who work directly with the birds. By using a specialized culture method that encourages the growth of these specific bacteria, followed by advanced molecular testing to identify exactly which species were present, the scientists aimed to determine the true scale of the risk in this region.
The investigation revealed that these bacteria are indeed common in the markets. Out of every four samples taken, roughly one tested positive for the presence of Campylobacter. When looking specifically at the chickens, the bacteria were found in about 23 percent of the birds. However, a clear pattern emerged regarding the type of chicken. The local, free-range chickens, which roam more freely and interact with the environment, carried the bacteria at a significantly higher rate than the commercial broilers raised in more controlled settings. The local birds were nearly three times more likely to be infected than their commercial counterparts. This difference suggests that the way the birds are raised and their exposure to the outside world plays a major role in how many germs they carry.
The study also looked directly at the people working in these markets. Among the 17 handlers whose hands were swabbed, nearly 30 percent tested positive for the bacteria. While the number of people sampled was small, the finding is significant because it confirms that the workers are frequently coming into direct contact with the germs. This occupational exposure highlights a critical point of transmission where the bacteria move from the birds to the humans, potentially spreading further if hygiene measures are not strictly followed. The researchers noted that the hands of these workers act as a direct link in the chain of infection, carrying the bacteria from the live birds to other surfaces or food.
To understand exactly what kind of bacteria they were dealing with, the researchers used a molecular technique that acts like a genetic fingerprint. They found that when the bacteria were present, Campylobacter jejuni was the dominant species, appearing in the majority of the identified cases. A smaller portion of the samples contained Campylobacter coli. Interestingly, more than half of the bacteria found could not be identified as one of these two specific types using the tests available, suggesting that other, less common varieties of the bacteria might also be circulating in the markets. This mix of species adds complexity to the picture, indicating that the microbial environment in these markets is diverse.
The findings from Maiduguri paint a clear picture of a public health challenge rooted in the daily operations of the live bird markets. The study confirms that these markets are active hubs where bacteria thrive, particularly in local chickens and on the hands of those who handle them. The higher infection rates in free-range birds compared to commercial ones point to the importance of farming conditions in disease control. Furthermore, the presence of the bacteria on the hands of the workers underscores the need for better hygiene practices and protective measures for those working in these environments. By identifying the specific bacteria and their prevalence, this research provides a solid foundation for developing targeted strategies to reduce the risk of infection for both the workers and the wider community in northeastern Nigeria.
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