Deaths due to infectious disease in the developed world have declined significantly since the 1940s, largely due to the development and widespread use of vaccines and antibiotics.
Antibiotics are used in humans and animals to target and kill bacteria (pathogens that cause infection and disease), stopping their spread. An unintended consequence of the frequent use of these medicines has been that infectious organisms have genetically adapted to them and have therefore become more difficult or impossible to kill. Treatment of patients infected with antibiotic-resistant bacteria fails, potentially causing death, and the infection is more likely to spread to others.
In developing or resource-limited countries, infectious diseases are more prevalent than in industrialized nations and also more likely to lead to death due to inadequate health systems. In urban environments, antibiotics are often distributed in pharmacies without requiring a prescription. This has caused increased levels of antibiotic resistance, especially in crowded urban and peri-urban slums where the pathogens are most likely to spread among the crowded population.
People in rural areas of these countries have less access to health care in general, and may take antibiotics when they aren’t needed (antibiotics do not kill infections caused by a virus). Also, inadequate sanitation practices and infrastructure contribute to the distribution of microbes and antibiotic-resistant genes. In general, antibiotic resistance in developing countries has been understudied by researchers and feasible approaches to combatting it are scant.
The Dantas Lab at Washington University (led by Institute scholar Gautam Dantas) has invested its resources into better understanding the distribution and dissemination of antibiotic-resistant genes in resource-poor settings in Latin America. The project is supported by the Edward Mallinckrodt Jr. Foundation Scholar Award.
Erica Pehrsson and Pablo Tsukayama of the Center for Genome Sciences and Systems Biology have been spearheading the project, which includes contributions from five universities in the US, Peru, and El Salvador, and blends ecological, microbiological, medical, and public health expertise in its approach. In some cases, medical students took time off from their studies to collect samples (and procure dry ice to protect them) so they could be shipped to the US for analysis. Researchers found higher amounts of antibiotic resistance in the crowded slums than in rural areas, noting that wastewater treatment did not filter out antibiotic-resistant genes.
“This project has huge public health implications,” Pehrsson said. “Certain waste disposal techniques we would recommend in these settings have unintended consequences. We need to be investing in waste management and health infrastructure.”
The research team hopes their work will lead to more studies on antibiotic resistance in resource-limited countries and will inform useful interventions to improve health outcomes and, ultimately, save lives.