Chickens from live poultry markets in Nigeria could be bad for your health – scientists explain why

Many breeders treat their animals with antimicrobial drugs. These are drugs that target bacteria, viruses, fungi, and parasites. But using them the wrong way can have undesirable results. Animals are known to develop drug resistance. This resistance has repercussions on animal and human health.

We wanted to know if this might be a problem in Nigeria’s poultry markets, where live birds are sold.

Multidrug resistance in live chickens is a major public health concern worldwide. When resistance develops, drugs become less effective against the disease they are meant to kill. Resistance can also spread and develop in people who eat foods that carry multidrug-resistant bacteria. The consequence could be that the treatment of a disease fails or that an infection reappears. The result could be a longer hospital stay and higher treatment costs.

The World Health Organization (WHO) has warned that antimicrobial resistance could be the next pandemic. Each year, more than 700,000 people die from antimicrobial resistance, slightly more than the global death toll from HIV-related deaths in 2021 or malaria in 2020. Antimicrobial resistance is estimated to cause more than 27 .3 deaths per 100,000 population in sub-Saharan Africa.

Our research focused on how poultry sellers used antimicrobials and what hygiene measures they took to prevent disease in their chickens. The research took place in the poultry markets of South West Nigeria. We also undertook to establish the presence of multiresistant Escherichia coli (E.coli) in live market chickens. E.coli is a common bacterium found in chickens and their environment.

Five of the markets we visited were registered and three were unregistered. They all worked pretty much the same way.

We found that antimicrobial use and hygiene practices were poor among chicken vendors in the markets we studied. Vendors gave sick and healthy chickens antimicrobials without a prescription from vets. The vendors also treated the chickens with human drugs – particularly antibiotics such as tetracycline and chloramphenicol – which they bought from pharmacies. These practices can have a detrimental effect on the effectiveness of antibiotics for the treatment of bacterial infections in humans.

Our analysis revealed that 56.3% of fecal samples taken from chickens contained E.coli who were multidrug resistant. We also found that extremely high levels of bacteria were resistant, especially to ceftazidime and imipenem. The WHO classifies these drugs as drugs of last resort. These are critically important antimicrobials in human medicine, as there are few other options to try if they no longer work. Without options, more lives could be lost to antimicrobial resistance.

Antibiotic resistance: a public health risk

Antimicrobial resistance is a global problem. But low- and middle-income countries, including Nigeria, are particularly at risk. Their national health systems are often ill-prepared to deal with the complex causes and complications associated with antimicrobial resistant infections. The treatment of livestock is poorly managed and may be contributing to the antimicrobial resistance crisis in animals and humans in the country.

To reduce overuse of antimicrobials in poultry and other livestock, sellers and other stakeholders in the poultry value chain will need better training. Interventions such as educational programs are needed. The aim would be to encourage responsible use of antimicrobials to protect animal and human health.

In addition, animal health professionals should contribute to the development of good policies for the use of antimicrobials. Livestock owners should ideally consult veterinarians to develop an animal health plan and should obtain prescriptions before treating their animals. More trained vets will be needed if this is to be achieved.

The government should establish national systems and centers for routine monitoring of antimicrobial use and resistance.

Finally, the national antimicrobial action plan should consider improving integrated surveillance and diagnostic capabilities. Previous surveys in Nigeria have already made recommendations on controlling drug use; their orientations can be considered.

The poultry sellers in our study want the government to shut down unregistered live bird markets. After the first outbreak of bird flu in 2006, the government made it compulsory to register poultry farms and live chicken markets. This was to ensure effective surveillance and early detection of poultry diseases, as well as accessibility to government interventions. If sellers can consult veterinarians more easily, they are likely to use drugs in a more discriminating way. And registered markets get rapid responses and veterinary services in the event of an outbreak.

Vendors also want live chicken markets to be better organized and have access to standardized and documented guidelines for hygiene and operation. They want satisfactory processing facilities and basic amenities to help them produce quality chicken products. Amenities such as electricity, clean water, good drainage and roads are lacking in most live chicken markets in Nigeria.