Man in Florida killed by rare, brain-eating amoeba Naegleria fowleri

A man has died after being infected by a rare, brain-eating amoeba called Naegleria fowleri, health officials in Florida have said.

The unnamed man may have been infected with the amoeba after he rinsed his sinuses with tap water using a neti pot, according to the Florida Department of Health. A neti pot forces water up through the nose and into the nasal sinus area. On 23 February, officials in Florida said the man had been infected with the amoeba and they announced his death on 2 March.

N. fowleri is a particularly pernicious amoeba, says Sutherland Maciver at the University of Edinburgh, UK, and a co-author of a 2020 paper questioning whether the amoeba was an “emerging parasite”, meaning cases will become more common in future.

“It gets into the nostrils while we’re swimming and then the amoeba penetrates the cribriform plate into the brain,” says Maciver. “It’s called the brain-eating amoeba, which is a lurid, but fairly defendable, nickname.”

Maciver says that N. fowleri is a “devastating infection for those who get it”, with a 96 per cent fatality rate. The infection is treatable, but because the symptoms are so similar to those of meningitis and infection with the parasite is so rare – up to 2020, only around 430 cases have been reported worldwide – people are often only diagnosed during a post-mortem.

If a doctor is able to establish someone has an N. fowleri infection, they can attempt treatment with the drug miltefosine. “We’re not really sure how it works,” says Maciver. “It’s probably to do with the membranes.”

N. fowleri thrives in naturally occurring bodies of warm water. “The water has to be around 30°C almost permanently before the amoeba can compete with other things in the water,” says Maciver. Cases are concentrated in the US, he says, in part because of the high concentration of specialists in the country able to accurately diagnose the illness. This may overstate the country as a hotspot for infection.

“The other hotspot is Karachi, Pakistan,” says Maciver, “because Karachi has a very poor water-supply system. If you chlorinate adequately, you don’t have a problem – and also, importantly, that kills the bacteria on which the amoeba feeds.”

While infections are rare, Maciver suggests not swimming in warm, open water – and particularly recommends against flushing out your sinuses with water. “That’s a problem because the physical violence in the action can compromise the mucus membrane of the nose,” he says.