A recent field experiment that took place in Yellowstone Park sounds more like the plotline to a B-movie than the subject of serious scientific research.
Scientists from the Monterey Bay Aquarium Research Institute (MBARI) have been on the hunt for a "brain-eating amoeba" that kills 97% of those infected. Amoebae are tiny, single-celled organisms with no fixed shape.
The experiment was conducted in collaboration with the US Geological Survey (USGS) to study the deadly amoeba known as Naegleria fowleri using the Environmental Sample Processor (ESP) – an advanced biological sensing system that automatically analyses water samples on site.
If water or dust containing Naegleria gets into the nose, given the right conditions, the amoeba will move up the sinus nerve and into the brain, where it will begin eating the brain's nerve cells in the absence of its usual meal of bacteria.
The first symptoms, which appear between one and five days later, include headaches, fever and nausea. Subsequent symptoms include a stiff neck, lack of attention, confusion, loss of balance, seizures and hallucinations. The first onset of symptoms usually means death will occur within two weeks.
Even when the main antimicrobial treatment is administered, the death rate still exceeds 95%, although new treatments are being investigated. Luckily, the infection is not contagious and drinking water containing it will not harm you. Furthermore, it is not able to spread through water vapour or mist.
The amoeba is usually found in freshwater environments around the world, such as ponds, lakes, rivers, and hot springs and usually where temperatures exceed 30 °C. It has also been detected in sediment near the effluence from industrial plants or in unchlorinated swimming pools.
Fortunately, even though millions of people are exposed to Naegleria every year, infections are extremely rare. There have only been three confirmed cases in the UK, with the last occurring in the 1970s.
Most reported cases are in India and the southern United States, but even in the US only 40 people were infected between 2007 and 2016. Nevertheless, the new research will hopefully be able to contribute to minimising the risks of infection even further.
According to the Centers for Disease Control and Prevention: "There are no rapid, standardised testing methods to detect and quantitate Naegleria fowleri in water. It can take weeks to identify the amoeba, but new detection tests are under development."