Climate change and lack of sustainable policies may fuel rise in superbugs

Current climate change trajectories and failing to meet sustainable development strategies could contribute to an increase in the global burden of antimicrobial resistance (AMR) by 2050, according to a study published in Nature Medicine. The authors project that AMR could increase by up to 2.4% globally by 2050, and call for urgent action to address broader socioeconomic and environmental factors beyond simply reducing antibiotic use to mitigate the global AMR burden.

In 2021, bacterial AMR was responsible for an estimated 1.14 million deaths globally, disproportionately affecting low- and middle-income countries. This number is expected to increase to nearly 2 million deaths by 2050. Recognizing the severity of the AMR burden, world leaders of the 79th United Nations General Assembly issued a declaration committing to reducing the 4.95 million global bacterial AMR-related human deaths by 10% by 2030.

However, much of the AMR response has been focused on excessive antibiotic use, and less attention has been given to the context of climate change and socioeconomic conditions.

Researcher Lianping Yang and colleagues analyzed 4,502 records encompassing 32 million isolates of 6 key bacterial pathogens resistant to antimicrobials, obtained from 101 countries between 1999 and 2022. Using forecasting models, they investigated how socioeconomic and environmental factors and policies would influence global AMR trends.

Their findings suggest that under the worst-case climate change-adaptation scenario, in which global temperatures would increase by 4–5^o C by the end of the century (SSP5–8.5), AMR could increase by 2.4% by 2050, compared to the low-emission scenario (SSP1–2.6). This varied between 0.9% in high-income countries, and 4.1% and 3.3% in lower-middle-countries and lower-income countries, respectively.

Yang and colleagues also found that sustainable development efforts, such as lowering out-of-pocket health expenses, expanding immunization coverage, increasing health investments and ensuring universal access to water, sanitary and hygiene services, could reduce the future prevalence of AMR by 5.1% compared to the baseline. This would surpass the effect of reducing antimicrobial consumption, which is projected to lower AMR prevalence by 2.1%.

The authors acknowledge that causality cannot be drawn due to the ecological modeling approach, as well as limitations of the quality of AMR surveillance datasets. Additionally, the primary models did not account for certain factors that contribute to AMR, such as education, antimicrobial use in food production, and animal farming practices, owing to data unavailability.