The deadly brain-eating amoeba lurking in some water faucets

CDC researchers say that the two Louisiana individuals who died last year from a brain-eating primary amoebic meningoencephalitis (PAM) contracted the infection after using neti-pots with tap water harboring the bacteria, according to a study in Clinical Infectious Diseases.

The victims' deaths, the first recorded PAM cases in the U.S., were linked to the presence of Naegleria fowleri in the tap water they used to regularly clear their sinuses with neti pots, the study says. The municipal tap water tested negative for the bacteria, but one victim's tankless water heater and the other's sink and faucet tested positive for the bacteria.

CDC recommends individuals who use a similar device for nasal irrigation distill, filter, or boil the water before use.

How does PAM manifest in a patient?

PAM symptoms, similar to viral or bacterial meningitis, set in one to seven days after exposure.

In the first case, a 28-year-old man abruptly developed a severe headache, neck stiffness, back pain, confusion, fever, and vomiting. According to the study, he was disoriented when admitted to the ED.

In the second case, a 51-year-old woman developed symptoms over three days, including: nausea, vomiting, loss of appetite, fatigue, fever, and neck stiffness.

CDC says climate change could play a role

Naegleria fowleri is usually found in warm freshwater such as lakes, but the deaths suggest that the bacteria can colonize in household plumbing and tap water, as well. CDC researchers say there has been a shift north in the geographic pattern of where PAM cases are reported, perhaps due to a climate change or localized heat waves.

"It is unclear whether the increased temperature and heat waves projected in climate change models will lead to further expansion of the [amoeba's] geographic range," the study says (Petrochko, MedPage Today, 8/23).