Naegleria Fowleri And The Hot Spring

For many people, hot springs conjure up thoughts of cleansing and purity. For centuries, humans have visited hot springs to relax and recover. But as with any natural water body, hot springs can also exhibit biota that can infect and in severe cases kill.

“hot spring” Andy Blackledge © 2016

As reported by the LA Times, the Federal Centers for Disease Control and Prevention (CDCP) assigned a team of scientists and physicians in 2008 to study a spike in deaths caused by Naegleria fowleri, an amoeba found naturally in bodies of warm fresh water, such as lakes and hot springs. The free-living amoeba causes primary amebic meningoencephalitis (PAM), a disease of the central nervous system. Although rare, PAM is almost always fatal. Between 1962 and 2016, there have been 143 PAM infections in the U.S. with only four survivors.

According to the Times, the group was formed in response to six deaths in 2007 in Arizona, Florida and Texas, all attributed to the amoeba, which typically enters the body through the nasal passages and then attacks brain tissue. The six deaths in 2007 represented the sixth-highest annual number of cases since the 1940s. As reported by Water Online in other cases of infection, the brain-eating amoeba thrives in warm bodies of water.

The CDCP researchers were unable to determine why certain people get infected and what concentration of amoeba in the water poses a significant risk. Millions of swimmers enter warm freshwater pools each year without getting sick. The group recommended public health agencies disseminate more information on the risk of infection to potential swimmers.

Fast forward to September 2017 and a recent study of Yellowstone’s Boiling River. As reported in Wired, scientists from the Monterey Bay Aquarium Research Institute (MBARI) and the United States Geological Survey (USGS) continue to collect river samples for the CDCP to analyze for Naegleria fowleri.

According to Wired, the MBARI researchers are testing a new device that might be capable of detecting Naegleria fowleri in real time. First the CDCP will detect the amoeba with their lab methods. This includes using both molecular techniques to hunt for microbe DNA in the sample and culturing the parasite in a dish. Then if MBARI’s equipment can trap amoebas in its filters, the hope is that the machine will be capable of doing genetic testing in the field to identify the parasites. The work might help give USGS sensors the ability to alert authorities to amoeba outbreaks.

Until then, reading posted health notices and keeping your head above water when visiting the hot spring is a good rule of thumb.