One of the biggest threats to global health may become far worse in the coming decades for those countries without access to clean water and wastewater infrastructure.

According to an article recently published in Nature Microbiology, environmental transmission of antimicrobial-resistant bacteria may be a significant driver to antimicrobial resistance in impoverished communities in low- and middle-income countries.

If not addressed, that resistance could lead to increased mortality as more antibiotics become ineffective in the future.

“Unless we put in place systems to disrupt environmental transmission of antimicrobial-resistant organisms, these antibiotics will continue to be ineffective when people in these areas need them most,” said Mohammad Aminul (Amin) Islam, assistant professor at WSU’s Paul G. Allen School for Global Animal Health.

Islam is one of more than a dozen global health researchers on the paper proposing that water and wastewater infrastructure improvements in these settings should be evaluated for their effectiveness in limiting transmission of antimicrobial-resistant bacteria into the environment.

As antibiotics are consumed by animals and humans, and waste is not properly disposed of, the environment becomes contaminated with organisms that become resistant to antibiotics.

People exposed to these environments are subject to colonization by these bacteria.

In developed countries, antibiotic misuse in humans and animals is the most significant driver for antimicrobial resistance and has often been at the center of research on the issue.

However, recent studies, including one led by Islam, show a high level of colonization with antimicrobial-resistant organisms among healthy people living in these communities.

“We can cut down on antibiotic use but unless people have access to clean water and wastewater infrastructure is put in place, it will be challenging to reduce colonization and infections with antimicrobial pathogens among people in these settings,” Islam said.

Islam’s recent research is one of several studies referenced in support of the publication in Nature Microbiology calling for more studies on the environmental transmission of antimicrobial-resistant bacteria.

Islam said the link between antibiotic use and infections caused by resistant organisms works in a cycle among residents living in overcrowded and poor housing conditions.

“People living in these conditions are more susceptible to infectious diseases and therefore use antibiotics more frequently. If one antibiotic doesn’t work, they will go back and try a different antibiotic often prescribed by unqualified drug sellers,” he said. It ends up putting more people at risk because those antibiotics will make their way into the environment.

Islam said the COVID-19 pandemic likely makes matters worse.

While viruses cannot be treated with antibiotics, in the developing world, antibiotics are sold over the counter and can be purchased regularly by people who may believe they can treat their symptoms with antibiotics.

“Antimicrobial resistance is a global problem,” Islam said. “It’s different in developed nations but in these low-income countries the problem cannot be solved until we put in place sustainable systems to curb enteric pathogen transmission, and, thereby, environmental transmission of antimicrobial resistance.”