The amoeba Naegleria Fowleri is normally harmless.
But if it gets into the human body through the nose, the infection is usually fatal.
US authorities have now detected the pathogen in the public drinking water supply in the state of Texas.
Eight municipalities were initially affected.
Residents were asked to use tap water only to flush the toilet.
Authorities announced that the public water system would be disinfected, flushed and then re-examined for the pathogen.
The examination was ordered after a six-year-old boy died of an infection with the protozoa.
It is unclear whether the child was actually infected through tap water.
Not transferable from person to person
The warning now only applies to the city of Lake Jackson with a population of just under 27,000.
You could use the tap water again, but you should boil it before drinking it and be careful not to get water up your nose while bathing or showering.
Naegleria Fowleri only survives in warm fresh water.
According to the Robert Koch Institute, the amoeba is particularly widespread in waters and soils of the subtropics and tropics, but also in naturally or artificially heated freshwater in temperate climates.
According to the US health authority CDC, those affected usually become infected if contaminated water gets into the nose while bathing or diving.
If the amoeba migrates to the brain, it can trigger life-threatening inflammation.
So far not a single case is known in Germany
Because tissue is destroyed in the process, Naegleria Fowleri is also known as the "brain-eating" amoeba.
Experts rule out infections by swallowing or drinking.
The pathogen cannot be transmitted from person to person either.
Although the amoeba is relatively common, infections are rare.
In the USA, only 34 cases were documented between 2009 and 2018; others are known from Australia and France.
Researchers also assume that many cases in developing and emerging countries are not recognized as such and are therefore not reported.
In Germany, not a single infection with the amoeba has been documented.
After the amoebas attack the brain, it usually takes one to nine days for the disease to show up.
The first symptoms include severe pain in the front of the head, fever, and nausea.
This can lead to confusion, hallucinations, a stiff neck, and imbalance until people lose consciousness.
According to a specialist article from 2014, more than 95 percent of known infections are fatal.
On average, death occurs within five days of the first symptoms.
In the meantime, however, some cases have been documented in which sick people survived the infection after receiving the active ingredient miltefosine, which is actually used against leishmaniasis.
Because Naegleria Fowleri infection is so rare, the disease is usually recognized too late.
In 2018, a 29-year-old died as a result of the infection in the state of New Jersey.
His relatives then announced annual benefit events to draw attention to the disease.
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