Can brain-eating amoebas develop in untreated water that has been stored for several months?

　　The term "brain-eating amoeba" generally refers to Naegleria fowleri. Whether amoebas are present in untreated water stored for several months depends on whether the water source is contaminated and the storage conditions. If the water source is contaminated and the storage environment is favorable, amoebas may exist; if the water source is clean and the storage environment is unfavorable for the survival of the amoebas, they are unlikely to be present. The specific analysis is as follows:

　　If untreated water is drawn from natural water sources such as rivers or ponds contaminated by Naegleria fowleri and is stored in open containers, exposed to external contamination, and the storage temperature is suitable, the amoebas can multiply in the water. The cysts of Naegleria fowleri can survive in water for long periods, and the trophozoites can remain active under suitable temperatures, leading to the presence of amoebas in untreated water stored for several months.

　　When untreated water comes from disinfected tap water or has been boiled or filtered before storage, and if the container is sealed and stored in a cool, dry environment, Naegleria fowleri is unlikely to survive. Disinfection treatment can kill amoebas in the water, sealed storage prevents external contamination, and a cool environment inhibits the metabolism of the amoebas, or even causes their death. In such cases, it is unlikely for amoebas to be present in untreated water.

　　Avoid drinking untreated water stored for long periods, especially from unknown natural sources; use clean, sealed containers for storing water and keep them in a cool, dry place; if discomfort occurs after contact with untreated water stored for several months, seek medical attention promptly to check for possible Naegleria fowleri infection.