brain-eating infection in rivers and lakes

7.24: news.health/brain-eating infection in rivers and lakes:
Naegleria fowleri are brain-eating amebae
that enter the brain through the nose.
. there is always a low level of risk whenever they enter
warm freshwater lakes, rivers, and hot springs
(for example, when swimming, diving, or waterskiing),
particularly in southern-tier states.
. drinking infected water is not a problem [cdc].

Free-living amebae belonging to the genera Acanthamoeba,
Balamuthia, Naegleria and Sappinia
are important causes of disease in humans and animals.
Naegleria fowleri produces an acute, and usually lethal,
central nervous system (CNS) disease called
primary amebic meningoencephalitis (PAM).
Acanthamoeba spp. and Balamuthia mandrillaris
are opportunistic free-living amebae
capable of causing granulomatous amebic encephalitis (GAE)
in individuals with compromised immune systems.
Sappinia pedata has been implicated in a case of amebic encephalitis
Immune response may be the real killer
after infection with Naegleria fowleri