– Three lifeguards sat atop an observation platform Wednesday looking over an empty beach and no swimmers in Lake Minnewaska, a sign of unease over the news that a 14-year-old swimmer was fighting for his life because of a rare but frightening parasitic infection in the lake.

Swim lessons for 5- and 6-year-olds were moved to a local hotel pool and the usual handful of lunch-hour swimmers were nowhere to be found. “It’s sad to see it labeled, but it will make people aware of the situation,” said Mike Anderson, a Glenwood resident who has fished and swum in the central Minnesota lake since he was a boy.

Hunter Boutain, of Alexandria, Minn., remained in critical condition Wednesday night at the University of Minnesota Medical Center, after apparently inhaling the Naegleria fowleri amoeba while swimming in Minnewaska. The parasite, which has historically been found in warmer, southern U.S. lakes has now been confirmed in three cases involving Minnesota swimmers since 2010 and may have been involved in at least three other unconfirmed cases.

Boutain, who just finished eighth grade at Discovery Middle School, was largely unresponsive and breathing with a respirator, according to posts from his uncle on a family CaringBridge website.

“We are praying for a miracle for this rascal,” his uncle wrote.

Boutain’s infection occurred in a relatively large body of water — compared to the state’s prior two confirmed cases, which occurred in the much smaller Lily Lake in Stillwater — meaning that precautions should be taken when swimming in any freshwater lake, said Trisha Robinson, supervisor of the Minnesota Department of Health’s waterborne diseases unit.

“Prior to our 2010 case, the northernmost case was 550 miles south of us,” Robinson said. “It should be assumed that it can be anywhere. While the occurrence of the amoeba is common, infections fortunately are rare. That’s not to take anything away from the families that this has affected, because rare is not rare when it’s you.”

The surefire remedy is staying out of lake water entirely, but health officials viewed that as unlikely in a Land of 10,000 Lakes where swimming and boating is ingrained in the culture and economy. The infection has been confirmed only 129 times in the U.S. since 1962. But the severity of the infections does give pause. The prior cases in Minnesota resulted in the deaths of 7-year-old Annie Bahneman in 2010 and 9-year-old Jack Ariola Erenberg in 2012.

Two Minnesota parents are hoping to at least raise awareness to the amoeba and to the precautions, which include keeping your head above water or plugging your nose when you dive in. Chad and Heidi LaMeyer lost their 11-year-old daughter, Hailee, to a brain infection in 2008 that authorities later said was likely caused by exposure to N. fowleri while swimming in a lake near their old home in Stacy, Minn. They have since formed a nonprofit group, Swim Above Water, to alert families to the risks.

“You can drink water that has the amoeba in it and it does not affect you,” Chad LaMeyer said. “The only way you get this is to get water in your nose that has the amoeba and from there it gets into the brain.”

Symptoms develop rapidly, and typically involve severe swelling in the brain. Almost all of the known infections have resulted in deaths within days, though a 12-year-old Arkansas girl survived her infection in 2013. LaMeyer believes hospital and health officials hadn’t been looking closely for this infection in northern states until recently, which is why it wasn’t confirmed at the time his daughter died. His nonprofit website also references two other unconfirmed deaths, including of a 7-year-old from Iowa who died after swimming in the Detroit Lakes area.

Infections are considered more likely in shallow, warmer waters. The amoeba survives underground and then emerges to lake levels when temperatures warm up. Another prevention tip consequently is to refrain from churning up sediment on the lake bed, which can stir the amoeba into the water.

But LaMeyer said there have been cases nationally involving wakeboarders skimming over deep waters, and children on slip-and-slides using water from household garden hoses.

Adults are as susceptible to infection, but are less likely than children to submerge in lake water, Robinson said. “Children are more adventurous and more likely to participate in activities that would get water up their noses.”

The beach at Lily Lake remains closed years after the infections were discovered there. The U.S. Centers for Disease Control and Prevention conducted testing at that and nine other lakes in Washington County between 2010 and 2014. Six tested positive for the amoeba in 2010, but no trace was found in any of the water samples from the lakes in 2013 or 2014.

Robinson said the mere presence of the amoeba doesn’t make a lake unsafe, nor does the absence mean swimmers should ignore precautions.

She added that Minnewaska, an 8,000-acre lake along the communities of Glenwood and Starbuck, is no more of a risk than others. Glenwood leaders on Wednesday discussed whether to cancel any lake activities in the upcoming Waterama celebration, but opted to continue.

“It’s a shock,” said Kristina Kostelecky, the owner of Hunt’s Resort, one of at least three resorts on popular Lake Minnewaska. “I don’t know what to think about it.”

She said she was thinking about the boy’s family.

Tests wouldn’t help

Water quality tests are common on many lakes. Cities often check for E.coli bacteria, and Pope County officials test Minnewaska for algae levels and phosphorus, which usually comes from fertilizer and farm runoff, said Gary Maurstad, treasurer of the Pope County Coalition of Lakes.

Robinson said more testing for N. fowleri wouldn’t be effective, and is only conducted right now by the Centers for Disease Control and Prevention. LaMeyer agreed, noting that a negative test in one corner of a lake isn’t conclusive for the entire body of water.

LaMeyer recalled growing up in Anoka and going with a dozen friends to a nearby lake in the summers, when they would then dare one another to dive to the bottom and come up with a handful of muck. He doubts the recent infections will deter people from swimming in lakes. He watched his own nieces over the holiday weekend diving out of a canoe at a lake where the family has a cabin. But he hopes the precautions will sink in.

“This is a pain that we don’t want any other parent to go through,” he said.

Prayers and support poured into the CaringBridge site for Boutain, who played in his school orchestra and jazz band and helped produce a student-led video news program.

Some came from family and friends, others from people unnerved by the incident.

“I don’t know the family,” wrote a Sauk Centre woman, “but saw that a child was critically ill from a lake. And I think, as does many, this could’ve been my child. I will continue to say prayers.”