Climate change could increase risk of brain-eating amoeba, flesh-eating bacteria

More than 97 percent of reported cases of Naegleria fowleri are fatal.
More than 97 percent of reported cases of Naegleria fowleri are fatal. Photo credit: Getty Images

Climate change could contribute to a rise in flesh-eating bacteria which thrive in warmer waters, experts warn.

Scientists are becoming increasingly worried climate change can contribute to dangerous pathogens such as brain-eating amoeba Naegleria fowleri and Vibrio vulnificus, a flesh-eating bacteria growing more rapidly.

More than 97 percent of reported cases of Naegleria fowleri are fatal, with only four survivors of 148 known infections between 1962 and 2019, according to the CDC.

The amoebas enter the brain and cause a rare form of meningitis which is very difficult to treat. As soon as people begin to show symptoms it's very unlikely they will survive.

Vibrio vulnificus causes necrotizing fasciitis, a severe infection in which the flesh surrounding an open wound dies.

Not only are temperatures hotter, but they are hotter for longer periods of time, which allows the pathogens to grow in the water.

"It's intensifying the opportunity, and creating more opportunity, for these harmful things to cross our paths," Melissa Baldwin, director of Florida Clinicians for Climate Action, told ABC News.

But it's not just rising temperatures which can contribute to the faster growth of these dangerous infections.

Overflow water from extreme flooding can help the pathogens transmission, and strong hurricanes mean more salt water mixes with fresh to create brackish conditions in which Vibrio vulnificus thrives. 

According to the Ministry of Health website, nine people in New Zealand have contracted meningoencephalitis and died from Naegleria fowleri.

"It was first recognised in New Zealand in 1968 among people who had been swimming in untreated thermal pools in the central North Island.

There were eight fatal cases between 1968 and 1978 and a further death was reported in 2000.

Cases of Vibrio vulnificus infection in New Zealand are "extremely rare".