Curbing air pollution could help mitigate the impact of antibiotic resistance, say scientists from China and the UK after their modelling study found significant correlation between airborne particulate matter and aggregate antibiotic resistance levels.
In their paper, published in The Lancet Planetary Health, they wrote that the association is consistent across the globe and has grown stronger over time, reports CIDRAP.
In a scenario where countries implemented WHO-recommended policies to limit air pollution, they estimate that premature deaths attributable to resistant bacteria could be reduced by more than 20% by 2050.
Although they acknowledge more evidence is needed to verify the link, and that antibiotic overuse and misuse are still the main drivers of AMR, they say the findings provide more information on the role played by the environment in spreading resistant bacteria, and controlling air pollution could present a new pathway for fighting antibiotic resistance.
“Until now, we didn’t have a clear picture of the possible links between the two, but this work suggests the benefits of controlling air pollution could be two-fold: not only will it reduce the harmful effects of poor air quality, it could also play a major role in combating the rise and spread of antibiotic-resistant bacteria,” said lead study author Hong Chen, PhD, of Zhejiang University.
Antibiotic resistance genes in polluted air
The study, conducted by Chen and colleagues from Zhejiang University and the University of Cambridge, builds on previous research that has identified the presence of antibiotic-resistance genes in source-specific and ambient air.
Among the published research is a paper from 2018 that revealed the presence and abundance of 30 antibiotic-resistance gene subtypes in air samples from 19 cities in 13 countries. Other studies have found that the abundance of resistance genes in urban air is higher than resistance genes found in soil and river water.
Just as people can be exposed to resistant bacteria via food, water and soil, Chen and his colleagues say this research suggests people can also be exposed to resistant bacteria trapped in airborne fine particulate matter (PM2.5), the most dangerous airborne pollutant.
Inhalation of this bacteria could result in infections in the respiratory-tract system and other parts of the body, since PM2.5 can also penetrate the lung barrier and enter the blood system.
Although the underlying mechanism for how air pollution affects antibiotic resistance remains unclear, the study is the first to estimate the global associations between PM2.5 and clinical antibiotic resistance.
“Empirical evidence of the effects of PM2.5 on population-level antibiotic resistance that enable the global impact to be assessed is clearly needed,” the authors wrote. “The air environment can cross regional boundaries and spread antibiotic resistance over long distances and on a large scale, which could be a crucial link between the dissemination of environmental and human antibiotic resistance.”
For their analysis, the researchers used data collected from 116 countries from 2000 to 2018, including raw antibiotic resistance data on 11.5m tested isolates covering nine bacterial pathogens and 43 types of antibiotic agents. Apart from air pollution, they also evaluated data on other factors that have been linked to rising antibiotic resistance levels, including antibiotic use, sanitation services, economics, healthcare spending, population, education, and climate.
The analysis found that an increase in 1% of PM2.5 across regions was associated with increases in resistance ranging from of 0.5% to 1.9% in each of the nine pathogens. In addition, changes in PM2.5 concentration were linked to large increases in resistance since 2013.
It also showed that the magnitude of the contribution of PM2.5 to aggregate antibiotic resistance is greater than factors like drinking water and healthcare expenditures. The researchers estimated that antibiotic resistance derived from PM2.5 caused an estimated 480 000 premature deaths in and 18.3m years of life lost in 2018.
Limiting pollution could reduce resistance, attributable deaths
The researchers then modelled a set of scenarios to project how PM2.5 might affect antibiotic resistance and premature deaths in the future. If no policies to reduce air pollution were implemented and other factors were unchanged (the baseline scenario), they estimate that antibiotic resistance and premature deaths attributable to resistant pathogens would increase by 17% and 56.4%, respectively, by 2050, with the biggest impact seen in sub-Saharan Africa.
Several scenarios estimated that increasing healthcare spending, improving access to clean drinking water, and reducing antibiotic would significantly reduce levels of antibiotic resistance.
In a scenario where countries implemented policies to limit the annual PM2.5 concentration to 5 micrograms per cubic metre, the researchers estimated a 16.8% decrease in global antibiotic resistance and 23.4% reduction in attributable deaths compared with the baseline, with countries in North Africa and west Asia benefitting the most.
“Combined, these results suggest that although measures of other drivers of antibiotic resistance are still needed, controlling PM2.5 could be a promising way to reduce global antibiotic resistance,” they wrote.
Study details
Association between particulate matter (PM)2·5 air pollution and clinical antibiotic resistance: a global analysis
Zhenchao Zhou, Xinyi Shuai, Zejun Lin, Xi Yu, Xiaoliang Ba, Mark Holmes,
et al.
Published in The Lancet Planetary Health in August 2023
Summary
Background
Antibiotic resistance is an increasing global issue, causing millions of deaths worldwide every year. Particulate matter (PM)2·5 has diverse elements of antibiotic resistance that increase its spread after inhalation. However, understanding of the contribution of PM2·5 to global antibiotic resistance is poor. Through univariate and multivariable analysis, we aimed to present the first global estimates of antibiotic resistance and burden of premature deaths attributable to antibiotic resistance resulting from PM2·5 pollution.
Methods
For this global analysis, data on multiple potential predictors (ie, air pollution, antibiotic use, sanitation services, economics, health expenditure, population, education, climate, year, and region) were collected in 116 countries from 2000 to 2018 to estimate the effect of PM2·5 on antibiotic resistance via univariate and multivariable analysis. Data were obtained from ResistanceMap, European Centre for Disease Prevention and Control Surveillance Atlas (antimicrobial-resistance sources), and PLISA Health Information Platform for the Americas. Future global aggregate antibiotic resistance and premature mortality trends derived from PM2·5 in different scenarios (eg, 50% reduced antibiotic use or PM2·5 controlled to 5 μg/m3) were projected until 2050.
Findings
The final dataset included more than 11·5 million tested isolates. Raw antibiotic-resistance data included nine pathogens and 43 types of antibiotic agents. Significant correlations between PM2·5 and antibiotic resistance were consistent globally in most antibiotic-resistant bacteria (R2=0·42–0·76, p<0·0001), and correlations have strengthened over time. Antibiotic resistance derived from PM2·5 caused an estimated 0·48 (95% CI 0·34–0·60) million premature deaths and 18·2 (13·4–23·0) million years of life lost in 2018 worldwide, corresponding to an annual welfare loss of US$395 (290–500) billion due to premature deaths. The 5 μg/m3 target of concentration of PM2·5 in the air quality guidelines set by WHO, if reached in 2050, was estimated to reduce antibiotic resistance by 16·8% (95% CI 15·3–18·3) and avoid 23·4% (21·2–25·6) of premature deaths attributable to antibiotic resistance, equivalent to a saving of $640 (580–671) billion.
Interpretation
This analysis is the first to describe the association between PM2·5 and clinical antibiotic resistance globally. Results provide new pathways for antibiotic-resistance control from an environmental perspective.
CIDRAP article – Study links air pollution to rising antibiotic resistance levels (Open access)
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