As global temperatures warm, infection-causing bacteria that thrives in both saltwater and freshwater — like Vibrio vulnificus and Naegleria fowleri — are increasing too, and with it, so is the risk to humans, The New York Times reported Sept. 20.
V. vulnificus is a bacterium that exists in warm saltwater environments and can cause wound infections. They are not common, but if contracted, mortality rates are high. Similarly, N. fowleri, which exists in warm freshwater and causes brain eating amoeba infections, while rare also has a high mortality rate.
In March, a report published in Nature, found that between 1988 and 2018, incidents of V. vulnificus wound infections rose eight times. Annual cases used to sit at 10 and since then have trended around 80 each year, according to the study.
Along with the increase in these infections, researchers also found that individuals with V. vulnificus infections continued to be identified about 30 miles further north every year as temperatures in the water also increased.
The changing distribution of bacterial infections from water-thriving bacteria like V. vulnificus and N. fowleri has been linked to climate changes, experts say.
"Our projections indicate that climate change will have a major effect on V. vulnificus infection distribution and number in Eastern USA, likely due to warming coastal waters favouring the presence of bacteria and elevated temperatures leading to more coastal recreation," researchers wrote of their findings. "This shift increases the population at risk into the densely populated coastal regions of New Jersey and New York. Alongside population growth and an increasingly elderly population, this translates into a doubling of cases by 2041–2060."
A separate study released in May, published in the Ohio Journal of Public Health, determined that the "Increased incidence of N. fowleri in northern climates is but one of many ways climate change threatens human health and merits novel education of health care providers," suggesting that clinicians across Ohio, Indiana, Iowa and Minnesota prepare to see and treat increased cases.