Climate-Induced Heat, Floods Worsen Drug Resistance in Poorer Nations

Climate change is a major driver of antimicrobial resistance, especially in poorer countries, and stronger public health systems are critical to fighting back, says a new study in the journal Nature Medicine.

Rising temperatures fuel drug resistance to deadly bacteria, while floods destroy sanitation infrastructure. And as infectious diseases spread more easily, more antibiotics are used—which makes resistance more prevalent. So climate impacts are deeply intertwined with the growing threat of antimicrobial resistance (AMR).

That means sustainable development strategies that mitigate the impact of climate change on public health will be key to slowing AMR, especially in low- and middle-income countries (LMICs), finds a team of public health experts from China and around the world. The team was among the first to measure how such strategies could cut antibiotic resistance. They found that while efforts to reduce antimicrobial consumption by addressing the overuse and misuse of medications should continue, sustainable development strategies—like reducing pollution and improving access to health care services and clean water—stand to reduce AMR prevalence by more than twice as much.

They analyzed over 4,500 reports from 101 countries, covering more than 32 million samples of six major bacteria—including two drug-resistant E. coli strains and a bacterium known to cause hospital-acquired and ventilator-associated pneumonia. They found that simply cutting antibiotic use would reduce resistance by about 2%, but improving health systems and sanitation could lower it by more than 5%.

The team also measured the impact of global climate policy failure on AMR. Under the worst-case climate scenario, which would see global temperatures rise by 4° to 5°C from pre-industrial levels by 2100, AMR could increase globally by 2.4% by 2050, compared to the best case scenario.

LIMCs would suffer most, with AMR projected to rise 4.1% by 2050. This is because public health systems in these countries are already stretched thin, Lianping Yang, lead author and associate professor at Sun Yat-sen University in China, told SciDev.Net.

“When climate-related stresses occur in places with limited clean water, sanitation, and medical services, the risk of infections rises—and so does the reliance on antibiotics, which can accelerate resistance,” Yang said, identifying LIMCs in South Asia, Southeast Asia, and Sub-Saharan Africa as particularly vulnerable to AMR.

“In short, climate change acts as a multiplier of existing vulnerabilities, making the AMR problem more severe in parts of the world that are already struggling with basic health and environmental protections.”

Antibiotic-resistant bacteria caused more than 1.1 million deaths worldwide in 2021 alone. At the United Nations General Assembly’s second high-level meeting on AMR last September, global leaders pledged to cut deaths from antibiotic resistance by 10% by 2030.