African countries, including South Africa, have limited waste infrastructure and uneven water treatment systems, which exacerbates the problem of antibiotic resistance. Photo: Sustainable Seas Trust
While antimicrobial resistance (AMR) is commonly linked to the overuse of antibiotics in hospitals and animal farming, an environmental contributor is increasingly coming into focus: microplastics.
These small plastic particles, typically less than 5mm in diameter, are increasingly recognised not only as environmental pollutants but also as active vectors in the evolution and dissemination of antimicrobial-resistant bacteria. Although the crisis is unfolding worldwide, low- and middle-income countries are especially vulnerable because of limited infrastructure and inadequate waste management systems.
A perfect storm for AMR
Microplastics are now widespread in rivers, lakes, oceans, soils and even in the air we breathe. They originate from the degradation of consumer plastics, cosmetics, textiles and packaging, and persist for decades as they accumulate across ecosystems. Their danger lies not only in their persistence, but in their capacity to act as “rafts” for bacteria, viruses and genetic material, including genes that confer AMR.
These plastic surfaces create ideal conditions for the formation of microbial communities known as biofilms. Within these clusters, bacteria can exchange genetic material more efficiently, including antimicrobial resistance genes. Moreover, microplastics tend to adsorb antibiotics and heavy metals from their surroundings, increasing the selective pressure that favors resistant bacteria.
As a result, microplastics are transforming natural ecosystems into incubators of resistance. And these resistant bacteria do not remain confined. They can spread through water, air, food, and even within the human body.
A global crisis with local vulnerabilities
According to recent estimates, sub-Saharan Africa alone generates about 17 million tonnes of plastic waste annually, yet more than 90% of it is not recycled. Rapid urbanisation, population growth, and inadequate waste management systems contribute to the accumulation of plastics in waterways and open dumpsites.
One illustrative example is the Nile River Basin, where microplastics have been detected at concerning levels. In cities such as Cairo and Khartoum, untreated wastewater and discarded plastic waste frequently end up in the river, creating environmental hotspots for antimicrobial resistance. Similar patterns have been documented around Lake Victoria, one of Africa’s largest freshwater bodies, which supports the livelihoods of more than 40 million people.
Further south, South Africa presents a particularly telling case. Despite being one of the continent’s most developed countries, its waste management infrastructure continues to face serious problems. A 2024 study conducted in Cape Town’s Diep River and adjacent coastal waters revealed alarming levels of microplastic contamination.
Health systems on the front line
The African continent bears a high burden of infectious diseases, many of which are still treated with older, widely available antibiotics. If AMR continues to spread unchecked, the consequences will be severe. This includes not only loss of human life but also increased pressure on already fragile healthcare systems.
Microplastics are complicating efforts to control resistant infections in ways that are not yet fully understood or reflected in current policies. Environmental reservoirs of resistance are rarely included in surveillance systems, and when they are, microplastics are often overlooked as a contributing factor.
Wastewater treatment plants, for instance, are critical points where microplastics and antimicrobial resistance genes converge. In many African cities, these facilities are either inadequate or entirely lacking. As a result, untreated waste containing plastic debris, antibiotics, and resistant bacteria is discharged into rivers and soils, reinforcing a dangerous cycle of contamination and AMR.
Towards sustainable solutions
Addressing this complex and interconnected crisis requires action on multiple fronts. First, it is essential to reduce plastic production and improve waste management, especially in urban areas. Policies such as bans on single-use plastics and incentives for recycling can make a meaningful difference, provided they are properly implemented and enforced.
Second, environmental monitoring systems should begin to include both microplastics and antimicrobial resistance genes as indicators of ecosystem health. This would allow policymakers to detect hotspots and take action before resistance spreads further.
Third, the scientific community must broaden its focus. Although most research on AMR has concentrated on clinical and agricultural settings, the environment must now be recognised as a critical front. This shift requires interdisciplinary collaboration among microbiologists, environmental scientists, engineers, and public health professionals.
Encouragingly, several promising innovations are emerging. Nature-based solutions such as constructed wetlands, which use plants and microorganisms to clean wastewater, have shown potential to reduce both microplastic pollution and the prevalence of antimicrobial resistance genes. These systems are cost-effective, adaptable, and well suited to the needs of many African regions.
The role of public awareness
Perhaps most importantly, we must acknowledge that this is not solely a scientific matter. It is also a social and political issue. People need to be involved in and empowered to reduce plastic consumption, demand improved sanitation, and understand the connections between environmental pollution and human health.
Educational campaigns, particularly those aimed at young people and urban populations, can help shift behaviours and build public momentum for change. Public interest media play a vital role in making these connections visible and accessible to the broader public.
Dr Jose L Balcazar is Senior microbiologist at the Catalan Institute for Water Research (ICRA-CERCA), Spain. His research explores the mechanisms and factors that promote antimicrobial resistance.