KENYA/TANZANIA - A study published in the Emerging Infectious Diseases journal has revealed alarming rates of antimicrobial resistance (AMR) in Campylobacter isolates from human and poultry samples in East Africa. 

The study, one of the largest to use whole genome sequencing (WGS) to characterize Campylobacter in the region, found that 75 percent of human and poultry isolates from Kenya and Tanzania showed resistance to antibiotics.

Campylobacter, a leading cause of foodborne illness, is prevalent in sub-Saharan Africa, where consumption of chicken meat is a major contributor to campylobacteriosis. 

While WGS has become a valuable tool for understanding foodborne pathogens globally, its application in African studies has been limited. This new research bridges that gap, exploring the relationship between Campylobacter in poultry and its impact on human health, particularly in relation to AMR.

Widespread resistance and multidrug resistance

The study analyzed 178 Campylobacter isolates—81 from human clinical cases and 97 from poultry farms—collected from both Tanzania and Kenya. 

Antimicrobial susceptibility testing revealed a high prevalence of AMR, with multidrug resistance (MDR) being particularly pronounced in poultry isolates. 

Around 41 percent of poultry isolates exhibited MDR, defined as resistance to three or more antibiotic classes, compared to just 2.5 percent of human isolates. Common resistance was noted to tetracyclines, fluoroquinolones, and sulphonamides.

The research also uncovered a significant genetic similarity between human and poultry isolates, suggesting that poultry plays a considerable role in the transmission of AMR Campylobacter to humans. 

Among the findings, several previously unreported sequence types (STs) were identified, indicating a high level of genetic diversity.

Complex population structure

The study identified 78 distinct STs across all isolates, with some STs present in both human and poultry samples, highlighting cross-species transmission. 

Of the identified STs, 27 had been previously recorded in other African countries, while many were entirely new. ST353 was one of the most common among both human and poultry isolates, found on multiple farms, indicating its widespread nature.

In poultry samples, five isolates exhibited resistance to five of the six antibiotics tested, showcasing the increasing threat of MDR in food production systems. 

The research highlighted that poultry farms are a critical reservoir for AMR Campylobacter, highlighting the need for enhanced biosecurity measures and better governance of antibiotic use in the food industry.

Call for greater surveillance and better governance

The study's findings emphasize the urgent need for improved surveillance systems in East Africa to monitor and control the spread of AMR in both human and animal populations. 

The researchers called for the integration of genomic tools like WGS into formal surveillance systems, as well as a more comprehensive understanding of the drivers of resistance, including antimicrobial use and biosecurity protocols.

With Campylobacter increasingly exhibiting resistance to multiple antibiotics, the study warns of the potential consequences for public health. The researchers urged for better regulation of antimicrobial use in both food production and healthcare to curb the spread of AMR.