Rare fatal infection caused by 'brain-eating amoeba' confirmed in Florida, experts issue warning
A rare and devastating infection of the brain, which is caused by an amoeba that destroys the brain tissue and is usually fatal, has been confirmed in Florida's Hillsborough County. The Florida Department of Health (DOH) has not disclosed any further details about the patient.
"The Florida Department of Health has confirmed one Florida case infected with Naegleria fowleri in Hillsborough County. Naegleria fowleri is a microscopic single-celled living amoeba. The amoeba can cause a rare infection of the brain called primary amebic meningoencephalitis (PAM) that destroys brain tissue. The amoeba is commonly found in warm freshwaters such as lakes, rivers, ponds and canals," warned the department.
Naegleria fowleri is usually referred to as the "brain-eating amoeba" or "brain-eating ameba". Infection with Naegleria fowleri is most common in the US during the summer months of July, August and September. The disease has public health importance because of its high fatality. Only four out of 143 known infected individuals in the US from 1962 to 2016 have survived, says the DOH.
In Florida, there have been 37 reported cases with exposure to the amoeba since 1962. Before 2008, primary amebic meningoencephalitis was not a reportable disease in Florida. "From 1962 through 2017, 35 cases have been documented with Florida exposures. Of these, 22 were exposed in Central Florida. Reported cases described exposures in the following counties: Baker, Brevard, Broward, Citrus, Hendry, Lee, Madison, Orange, Pasco, Pinellas, Polk, Putnam, Palm Beach, Seminole, Volusia and three unknown counties. One additional case was a Florida resident who acquired the disease at a natural hot springs recreational water venue in a Central American country. All Florida cases died from the disease except for a 2016 case. All but three cases were residents of Florida," says the department.
How does it spread?
Naegleria fowleri infection cannot be spread from person to person contact and will not occur as a result of drinking contaminated water. Generally, exposure to the ameba occurs when people use warm freshwater for activities like swimming, diving or other rigorous activities. "Two cases of PAM in the US have been linked to the use of household tap water for the irrigation of sinuses. Infections usually occur when temperatures increase for prolonged periods, which results in higher water temperature and lower water levels," say researchers.
Infection can happen when contaminated water enters the body through the nose. Once the amoeba enters the body through the nose, it travels up the nose to the brain where it destroys brain tissue causing primary amebic meningoencephalitis.
Health experts do not know why certain people become infected with the amoeba while millions of others exposed to warm recreational fresh waters do not, including those who were swimming with people who became infected. "The low number of infections makes it difficult to know why a few people have been infected compared to the millions of other people that used the same water or similar waters across the US," reads the statement.
What are the symptoms?
The initial symptoms of PAM start 1 to 14 days after infection. Initial signs and symptoms include headache, fever, nausea, vomiting, and stiff neck. As the ameba causes more extensive destruction of brain tissue, this leads to confusion, lack of attention to people and surroundings, loss of balance and bodily control, seizures and hallucinations. The disease progresses rapidly and infection usually results in death within 3 to 7 days. "While prompt diagnosis and medical treatment may influence successful outcomes, it is unclear what specific treatment regimen is effective," say experts.
What precautions can be taken?
According to experts, the only known way to prevent Naegleria fowleri infections is to refrain from water-related activities. The Department of Health has cautioned those who swim and dive frequently in Florida’s lakes, rivers and ponds during warm temperatures about the possible presence of Naegleria fowleri. "Adverse health effects on humans can be prevented by avoiding nasal contact with the waters since the amoeba enters through nasal passages," it warns.
Some simple measures can also be taken that might reduce risk by limiting the chance of contaminated water going up the nose, say experts, This includes avoiding water-related activities in bodies of warm freshwater, hot springs, and thermally-polluted water such as water around power plants, as well as avoiding water-related activities in warm freshwater during periods of high water temperature and low water levels. "Hold the nose shut or use nose clips when taking part in water-related activities in bodies of warm freshwater such as lakes, rivers or hot springs. Avoid digging in or stirring up the sediment while taking part in water-related activities in shallow, warm freshwater areas," says the health department.
The DOH noted that it is possible to be exposed to the amoeba through a neti pot when rinsing congested sinuses or conducting religious rituals with tap water. "Use only boiled and cooled, distilled, or sterile water for making sinus rinse solutions for neti pots or performing ritual ablutions," recommend experts.