NEW YORK — The 3-year-old girl wandered away from her grandmother’s home in Wareham, Mass., in mid-April. A frantic search began almost immediately, and within an hour little Alyvia Navarro was found unresponsive in a nearby pond. She was pronounced dead the next day.
A month later, across the continent, a larger search unfolded over three days as hundreds of emergency service personnel and volunteers fanned out around Clearlake, Calif., looking for 9-year-old Mikaela Lynch after she vanished from her backyard. The outcome grimly echoed the Wareham search: Mikaela’s body was found in a muddy creek.
The two girls were the first of at least 14 children with autism known to have died this year after slipping away from their caregivers. All but one of them drowned, evidence of a fascination that many autistic children have with water. The body of the latest victim, 11-year-old Anthony Kuznia, was found Thursday in the Red River after a 24-hour search near his home in East Grand Forks, Minn.
The tragic phenomenon goes by various names — wandering, elopement, bolting — and about half of autistic children are prone to it, according to research published last year in the journal Pediatrics.
That would be a huge number. The Centers for Disease Control and Prevention estimated last year that 1 in 88 children are affected by autism, and a federal survey this year pegged the prevalence rate at one of every 50 schoolchildren — more than 1 million in all.
Wandering has led to the deaths of more than 60 children in the past four years, and the fear of it can make daily life a harrowing, never-let-your-guard-down challenge for parents.
‘‘We take steps at home — locks on every door, gates, alarms,’’ said writer Jo Ashline of Orange, Calif., whose 11-year-old son has autism. ‘‘But there’s always, in the forefront of our minds, the thought that one tiny mistake could prove fatal.’’
Groups that advocate for autism-affected families, including the National Autism Association and Autism Speaks, are now making it a priority to increase awareness of wandering — among parents, professionals who deal with autistic children, and first-responder agencies that handle missing-children cases.
The study in Pediatrics found that half of parents with autistic children had never received advice or guidance from a professional on how to cope with wandering.
Among those trying to change that is Sheila Medlam of Colwich, Kan., whose 5-year old son, Mason, drowned in a pond in July 2010 after squirming out of the family home through a window that had been raised about 8 inches.
Medlam was at work; her adult daughter was at home but didn’t see Mason’s getaway.
‘‘It only takes a second of inattention and they’re gone,’’ Medlam said in a telephone interview. ‘‘They’re fast, they’re quiet. They can disappear in an instant.’’
Medlam now works with autistic children, operates a website that keeps track of wandering-related deaths, and lobbies for a national alert system that would improve emergency responses.
On her website, she has written a wrenching account of the day Mason died — blaming herself for leaving the window open and for omitting potentially helpful details when she called 911, and blaming the first responders for lack of knowledge about how to search for autistic children.
‘‘If only I could redo that day and just change one thing. But I can’t,’’ Medlam wrote.