In the aftermath of a hurricane, the media’s initial focus is on property damage and search and rescue operations, but there are long-term effects that can linger for years, long after the media has lost interest in recovering areas. Hurricanes can have unforeseen impacts on cities’ water supplies, increasing the risk of contamination with harmful bacteria from local water sources and the soil. The southern United States, which offers warm weather almost year-round, is particularly vulnerable to heat-loving microorganisms like the brain-eating amoeba Naegleria fowleri.
Viruses and bacteria cause the vast majority of infections in humans, but Naegleria fowleri has an uncommon and disturbing appetite for human brain tissue. Infection is incredibly rare but has a dismal survival rate. (Four patients have survived out of 143 documented cases in the United States.) And experts are concerned that Hurricane Katrina may be partially to blame for the three documented cases in Louisiana since 2005. Damage to water systems can increase the risk of contamination with bacteria from the soil, and population drops after natural disasters can give water time to stagnate in pipes. As the water sits in aged pipes in the summer heat, the chlorine used to kill microorganisms in public water evaporates, and parasites like Naegleria fowleri can thrive.
Florida is already tied with Texas for the most Naegleria fowleri cases in the country, and damage from Hurricane Irma may put the public at even greater risk. Residents should be aware of the infection process and how to stay safe.
Naegleria fowleri thrives during the warmest months of the year, and can be found in lakes, rivers, and hot springs, as well as in soil. Tap water and pool water are less commonly contaminated but cause a large proportion of human infections. Water contaminated with Naegleria fowleri is actually perfectly safe to drink (as long as there’s nothing else in it that could make you sick), but you could become infected if the water enters your nasal passages. Children are particularly vulnerable to infection, and documented sources of infection include the use of neti pots and playing and/or swimming in contaminated water.
When the amoeba enters the nasal passage, it works its way up the olfactory nerve and into the brain. The body recognizes the invader once brain tissue is attacked and triggers an inflammatory response. This is called primary amebic meningoencephalitis (PAM). Symptoms are similar to those of bacterial meningitis and can be difficult to diagnose, but accurate diagnosis is key since antibiotics aren’t an effective treatment for PAM. The disease most commonly begins with symptoms like headache, fever, nausea, and vomiting and then progresses to seizures, hallucinations, and coma.
Better diagnostic procedures and aggressive new treatments offer some hope and have saved lives in the last few years, but the infection is still a dire diagnosis. Because of the PAM’s rarity and the difficulty in distinguishing it from other causes of meningitis, the CDC says that three out of four diagnoses are made only after an autopsy in which the patient’s brain tissue is tested for the presence of the amoeba.
If you’re not sure that your water is safe (or if you know it’s contaminated), especially after a natural disaster, there are steps you can take to avoid infection. First, use a nose clip if you need to swim in water that you’re not sure is safe. Remember that, as far as we know, Naegleria fowleri can only harm you if it gets inside your nasal passages. Also consider avoiding swimming in hot springs, lakes, or unchlorinated spas or swimming pools. (While contamination with Naegleria fowleri isn’t common, it’s also not the only thing out there that thrives in stagnant water and can make you sick.) And if you’re unsure of the safety of your tap water, especially if you’re returning to your home after an evacuation, run baths shower taps, and hoses for at least five to ten minutes to flush the pipes.