A 12-year-old girl contracted a rare infection caused by a brain-eating amoeba in Arkansas, and it may be tied to summer heat and drought conditions, according to the Centers for Disease Control and Prevention (CDC).
The amoeba, or single-celled organism, that caused the infection is called Naegleria fowleri, which lives in warm freshwater, such as lakes, rivers and hot springs. These organisms can travel up the nose to the brain and spinal cord as people swim or dive and can cause a deadly infection called Primary Amebic Meningoencephalitis (PAM).
The Arkansas Department of Heath (ADH) said in a press release that the most likely source of the Arkansas infection is the Willow Springs Water Park, located south of Little Rock, Ark. Another case of PAM in 2010 is also believed to be connected to Willow Springs.
"Most of the cases occur in what we call the southern-tier states, and, in fact, about 50 percent of cases have occurred in Texas and Florida," Dr. Jennifer Cope, medical epidemiologist at the CDC, said.
The Arkansas case is the first confirmed one of 2013, Cope said. In the last decade from 2003 to 2012, 31 infections have been reported in the U.S.
Naegleria fowleri is thermophilic, or heat-loving. Most infections occur during July, August and September when there is prolonged heat and thus higher water temperatures and lower water levels.
This graph from the CDC shows the number of cases of PAM by state of exposure in the U.S. from 1962-2012.
"When we go back and look at where exposure may have occurred, we see the infections occur where water levels are low or where there are drought conditions or after a heat wave," Cope said.
More than half of Arkansas, about 52 percent, is being gripped by moderate drought conditions, according to the latest U.S. Drought Monitor report.
From July 5-24, high temperatures in Little Rock failed to reach the 90-degree mark or higher on only one day, on July 13. Overall, temperatures have been near normal in the Little Rock area this summer.
The Willow Springs Water Park closed on July 25, 2013, as a result of the recent infection, despite daily maintenance and a system to keep the water clean. In a Facebook post, Owners of Willow Springs Water Park David and Lou Ann Ratliff said, "We would never knowingly endanger your children and ours... We check and maintain our water daily with a sophisticated system that saturates our water with chlorine. We have added a water cannon, which drops the water temperature to a range inhospitable to bacteria growth, therefore we are not considered a warm body of water like all of our local lakes, rivers, and streams."
The initial symptoms are exactly the same as bacterial meningitis and typically start five days after the infection: headache, fever, nausea, vomiting and a stiff neck.
During the later stages of the infection, people develop seizures, become lethargic and can develop an altered mental state and eventually go into a coma.
There is only one known survivor of PAM in the U.S.
"It's very devastating and heart-breaking to the families impacted," Cope said.
Hold your nose shut, use nose clips or keep your head above water in warm bodies of freshwater.
Avoid digging in or stirring up the sediment while taking part in water-related activities in shallow, warm bodies of freshwater.
Avoid water-related activities in warm freshwater during periods of high water temperature and low water levels.
Do not put your head under water in hot springs.