Hunter Boutain, who died last month after swimming in a Pope County lake, did not die from a suspected brain infection caused by an amoeba as initially reported.
The Minnesota Department of Health said in a news release Monday that testing done by the CDC shows the 14-year-old died from streptococcal meningoencephalitis, not Primary Amebic Meningoencephalitis (PAM) as initially suspected.
Boutain, from Alexandria, had gone swimming in Lake Minnewaska and became “critically ill” shortly afterward of a suspected PAM infection, which the MDH describes as “very rare and severe.” It's caused by a microscopic amoeba called Naegleria fowleri, found in fresh water and soil around the world. Infection only occurs when the organism enters a person’s body through the nose – usually when people get water in their nose while swimming or diving – and then travels to the brain, according to the health department.
Boutain died a few days later.
On Monday, the department said initial clinical findings – including preliminary laboratory testing from the health care facility and his recent swimming exposure – led them to suspect PAM was the cause of death.
As a "standard confirmation step," the health department said, the CDC then did its own testing – the results did not support the initial finding, and instead pointed to streptococcus meningoencephalitis.
Streptococcus meningoencephalitis is the most common cause of bacterial meningitis in children and adults in the United States, the Mayo Clinic says. From 2003-2007, there were roughly 4,100 cases of bacterial meningitis each year, including 500 deaths, the Centers for Disease Control and Prevention reports.
The CDC notes signs and symptoms of PAM are similar to bacterial meningitis.
"The laboratory results help bring clarity to the situation, but do not lessen the tragic nature of this case," the Minnesota Department of Health says, but notes the risk of Naegleria fowleri in waters is still present, but very low.
Naegleria thrive in warm water, so infections are more common in southern states. The number of people who become ill is relatively low, with 35 cases reported across the country between 2005-2014, the health department notes.
Two children in Minnesota died of PAM in recent years – a 7-year-old girl in 2010 and a 9-year-old boy in 2012. Both of them became infected while swimming at Lily Lake near Stillwater.
PAM is also suspected, but unconfirmed, as the cause of death for two other children, the Pioneer Press reported.