Rising Temperatures Could Help Brain Eating Amoeba

Naegleria fowleri is a brain eating amoeba that earns itself national attention at least once a year after infecting an unsuspecting swimmer during the summer season. Now researchers are saying that with rising global temperatures, the prevalence of these heat-loving microbes could go up.

The Naegleria fowleri-related death of a 9-year-old Kansas girl is serving as a harsh reminder about the dangers of infections of the brain called primary amebic meningoencephalitis (PAM).

"We are very saddened to learn of this unfortunate circumstance, and our thoughts and prayers are with the family and friends during this difficult time," Robert Moser, Secretary and State Health Officer for the Kansas Department of Health said in a statement.

"It is important for the public to know that infections like these are extremely rare and there are precautions one can take to lower their risk - such as nose plugs," he added.

Infections causing PAM may be rare - with only 34 cases occurring in the US over the last decade - but Armand Kuris, a scientists at UC Santa Barbara studying infectious disease transmission, says that organisms like Naegleria fowleri, called sapronoses, need to be more closely watched as the world heats up.

 "Sapronoses do not follow the rules of infectious diseases that are transmitted from host to host," Kuris said in a recent release. "They are categorically distinct from the way we think infectious diseases should operate."

In the case of many infectious diseases, their prevalence is dependent on how many people can be infected. This is why vaccinations are so efficient against diseases like measles, where if there is no new host to jump to, it quickly dies out.

Sapronoses like Naegleria fowleri however do no use their host as an adequate environment. The amoeba flourishes in sun-warmed water even if no humans are around, and can build in population until an unsuspecting swimmer accidentally takes water down their nose. Then disaster strikes.

According to a study authored by Kuris, among of 150 randomly selected human pathogens examined, one-third turned out to function in this manner - an alarming finding.

Co-author Kevin Lafferty added that to prevent future infection, medical professionals are going to need to think outside of the box.

"To combat sapronoses, we need new theories and approaches," he said. "Our paper is a start in that direction."

The study was published in the August issue of Trends in Parasitology.