What happens when climate change and superbugs collide?

Climate change and antimicrobial resistance (AMR) represent two of the most urgent threats to our health. So, what happens when they collide? That’s the question ESR is exploring as part of a new project funded by the New Zealand Government’s Strategic Science Investment Fund (SSIF).

The research project From micro to macro scale: environmental AMR in the age of climate change will simulate rising temperatures, UV exposure and saltwater intrusion to study how climate-related factors could affect drug resistance in New Zealand’s natural environment. Additionally, planned field studies will compare AMR levels before and after extreme weather events to further understand the real-world impact.

Climate impacts

Many diseases are expected to exacerbate with changing climate conditions. Shifts in environmental factors, such as temperature and weather patterns, can increase the spread of bacterial, viral, parasitic and fungal diseases in humans, animals and plants. The increased risk of transmission may be coupled with an increased risk of resistance to antimicrobials. For example, WHO reports fungicide resistance in crops may be increasing with rising temperatures. And a US study found that an increase in local temperature was associated with increased resistance in harmful microbes in sick people.

Meanwhile, climate change can stimulate the ‘stress response’ in pathogens, accelerating mutation rates as bacteria figure out how to combat the drugs we have. Climate change could also lead to the emergence and spread of new and re-emerging threats. Candida auris, a fungal pathogen that is often multi-drug-resistant, has long existed in the environment, but evidence suggests the climate crisis may be responsible for it becoming more pathogenic in humans. This could all add up to a greater reliance on antimicrobials, further fuelling drug-resistant infections.

Extreme weather, extreme pathogens

An increase in extreme weather events and natural disasters, such as heatwaves, floods and forest fires are wreaking havoc here in New Zealand and around the world in ways that can increase the spread of antimicrobial resistant microbes.

For example, floodwaters may carry antimicrobial resistant microbes from wastewater systems into homes, businesses and fields. For example, when Hurricane Harvey hit the southern United States, there was an increase in the predicted presence of antimicrobial resistance genes in samples of soils, surface and groundwaters.

What about New Zealand—how could climate change influence drug resistance in our unique environment? That’s what ESR’s research aims to find out. The project will be the first study here to explore the impact of climate change on AMR in the natural environment. It will also be the first in New Zealand to explore this issue from a One Health perspective, an integrated approach that recognizes the interconnectedness of human, animal, plant and environmental health.

Addressing the dual challenges of climate change and AMR through this lens is crucial, as both threats affect multiple ecosystems and require coordinated solutions to protect global health.