How is climate change effecting waterborne diseases?

A blog post by Nina Baskerville, Microbiologist for BlueAdapt

For this year’s World Water Day, the theme “Water for Peace” has a tangible link to the work we are doing in BlueAdapt. Findings and tools developed by our research will provide resources for both high and lower-income countries facing increased water pressures all over the world. Our microbiology work will feed into a new One Health Framework that helps decision-makers understand the critical links between coastal waters, climate change, and human health.

Image caption for above: Here I’m testing the survival of E. coli and enterococci within treated and untreated sewage at different salinities.

So, what is microbiology and how does it link to protecting water?

Microbiology, the study of microorganisms, is at the heart of our research, in particular viruses and bacteria found in European coastal waters. These microbes, although invisible and often harmless, can significantly impact human health, and there is growing concern that this may worsen with climate change.

In BlueAdapt, we want to better understand the survival of harmful bacteria and viruses in rivers and coastal water, while creating methods to predict how this will be impacted by climate change. To explore this, we expose bacteria and viruses to various climate pressures, such as temperature fluctuations, UV radiation, salinity changes, pH shifts, and how clear the water is.

What is the difference between bacteria and viruses?

Bacteria, as single-celled organisms, have their own metabolism, conducting processes like respiration and reproduction. In contrast, viruses are not living organisms and must rely on hijacking the cellular processes of a host cell to reproduce. Understanding how viruses behave under different climate scenarios is paramount, given their persistence in the environment.

By studying how viruses respond to the climate stressors we are testing, we aim to predict and prevent potential health risks from coming into contact with viruses in coastal environments. Among the viruses we study are those commonly found in wastewater, including adenovirus, norovirus, enteroviruses, and hepatitis A virus.

These pathogens, capable of causing gastrointestinal and respiratory illnesses and liver disease, pose significant challenges, especially in regions with inadequate sanitation and water treatment facilities.

Why are antibiotics becoming ineffective at treating bacterial infections?

On the bacterial front, we are working to understand the links between coastal environments, pollution, climate change, and antimicrobial resistance (AMR). Bacteria can develop resistance mechanisms, allowing them to survive exposure to antibiotics that once killed them. This means antibiotics are becoming increasingly ineffective at treating bacterial infections.

We are interested in how aquatic environments like rivers, lakes and oceans shape the evolution of AMR in bacteria like E. coli and enterococci, particularly focusing on genes responsible for resistance to critically important antibiotics. One particular bacteria of interest is the extended-spectrum beta-lactamase (ESBL)- producing E. coli. ESBL-producing E. coli can cause urinary tract and bloodstream infections, sometimes leading to life-threatening sepsis. Infections are difficult to treat with conventional antibiotics, due to the production of the ESBL enzyme that breaks down the antibiotic, and are associated with increased mortality.

Water users like surfers three times more likely to have antibiotic resistant bacteria in their gut

So far, we know that resistant bacteria like ESBL-producing E. coli can be found in coastal waters and evidence suggests people who are frequent water users like surfers are three times more likely to carry an ESBL-producing E. coli in their gut. We are working to understand how these human-associated bacteria respond to aquatic environments and to ultimately predict how climate change might influence bacteria like ESBL-producing E. coli in the environment.

How can we protect waters in drought and flood-prone regions?

BlueAdapt explores the complex interplay between climate change, aquatic pollution, and the spread of waterborne pathogens. Extreme rainfall may trigger more sewage discharges and warmer water temperatures could prolong the survival of pathogens in aquatic environments, increasing the associated health risks. We’re developing a set of BlueAdapt tools and resources to help stakeholders and policymakers understand, predict and prevent the health risks of climate change, coastal pollution and antimicrobial resistance.

This year’s theme “Water for Peace” highlights the necessity for international cooperation to tackle the pressures created by climate change. Aquatic environments supply many ecosystem services like carbon capture, food security, recreation, and provide economic livelihoods for many people. While some regions face droughts and others face flooding, the need for protecting our waters becomes ever more important. By uncovering the mysteries of microbial behaviour in changing environments, our work can inform policies and interventions to build resilience and keep people safe.