Deadly “brain-eating amoeba” infections have historically occurred within the Southern us . But cases are appearing farther north in recent years, likely due to global climate change , a replacement study finds.
The study researchers, from the Centers for Disease Control and Prevention (CDC), examined cases of this brain-eating amoeba, referred to as Naegleria fowleri, over a four-decade period within the U.S. They found that, although the amount of cases that occur annually has remained about an equivalent , the geographic range of those cases has been shifting northward, with more cases shooting up in Midwestern states than before.
N. fowleri may be a single-celled organism that’s naturally found in warm freshwater, like lakes and rivers, consistent with the CDC. It causes a devastating brain infection referred to as primary amebic meningoencephalitis (PAM), which is nearly universally fatal. Infections occur when contaminated water goes up an individual’s nose, allowing the organism to enter the brain through the olfactory nerves (responsible for your sense of smell) and destroy brain tissue. Swallowing contaminated water won’t cause an infection, the CDC says.
Because N. fowleri thrives in warm waters, up to 113 degrees Fahrenheit (45 degrees Celsius), it’s possible that warming global temperatures may affect the organisms’ geographic range, the authors said.
In the new study, published Wednesday (Dec. 16) within the journal Emerging Infectious Diseases, the researchers analyzed U.S. cases of N. fowleri linked to recreational water exposure — like swimming in lakes, ponds, rivers or reservoirs — from 1978 to 2018. They identified a complete of 85 cases of N. fowleri that met their criteria for the study (i.e. cases that were tied to recreational water exposure and included location data.