Always use sterile or boiled water for nasal washing abroad if you are uncertain of the tap water quality, particularly when travelling to subtropical and tropical countries. Only use bottled water if you are sure it is distilled or sterile, unless the bottled water has been boiled.
About Naegleria fowleri
Naegleria fowleri is a free-living amoeba that can attack the brain via the nasal mucosa and the olfactory nerve. It is also known as the "the brain-eating amoeba." The amoeba lives in freshwater and can reach the brain when contaminated water enters the nose.
The amoeba is usually transmitted when water enters the nose while swimming in lakes, rivers and unchlorinated swimming pools, but nasal washing with contaminated water is also a known risk factor.
Nasal washing is popular in yoga environments and is part of religious washing practices in many countries.
Symptoms appear within 1-7 days. The disease particularly affects young, healthy people causing severe meningoencephalitis, and it has a very high mortality. The disease is not transmitted by drinking contaminated water or spread by human to human contact. Boiling or chlorination of water kills the amoeba.
Naegleria infection is extremely rare, with just over 300 cases documented worldwide.
The amoeba thrives at high temperatures, especially between 25°C and 40°C and can survive for shorter periods at even higher temperatures.
The Thai health authorities have been made aware of the case and the assumed mode of transmission.