A Pennsylvania toddler is recovering after a tick bite led to a harrowing 4-day stint in the intensive care unit of a children’s hospital, where doctors struggled to determine the cause of his life-threatening illness. Three-year-old Jonny Simoson was ultimately diagnosed with a rare tick-borne disease called Powassan virus. 

According to the Centers for Disease Control, many people who contract Powassan virus experience no symptoms, but the virus can cause severe disease, including infection of the brain and the membranes around the brain and spinal cord. Symptoms include confusion, loss of coordination, difficulty speaking, and seizure. One in 10 people with the severe form of the disease die. 

Although rare—only 178 cases have been reported in the U.S. since 2011, according to the CDC—the number of cases has increased in recent years. Most cases in the United States occur in the northeast and Great Lakes regions from late spring through mid-fall, when ticks are most active. There are no vaccines to prevent or medicines to treat Powassan virus.

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Jamie Simoson told the New York Post that she spotted a tiny speck on her son’s back while he was swimming on June 15. It turned out to be a tick smaller than a pen point. “It was not embedded. It was not engorged. I easily removed it with a pair of tweezers, and it was still alive,” Simoson told the Post. “He didn’t necessarily have any marks on his back shoulder until a few days later; there was just a tiny red bump. That was it.” 

Two weeks later, Jonny came home sick from daycare and his symptoms worsened over the next couple of days. After two trips to his pediatrician and a fever that spiked above 104 degrees, Jonny was taken to the ER, beginning a long stay in the hospital that would ultimately stretch to 12 days of testing and treatments, including four days in a pediatric intensive care unit. An MRI eventually found that Jonny exhibited signs of meningoencephalitis, an infection of the brain and the tissue that surrounds it. He responded well to intravenous immunoglobulin, a blood-product used to treat patients with antibody deficiencies. The diagnosis of Powassan virus came after he returned home from the hospital. 

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The once typically rambunctious toddler is now undergoing physical therapy to recover his full “ninja” mobility, but he’s progressing in his recovery, according to a Facebook page Jamie Simoson started to keep people posted on her son’s condition and to raise awareness about the dangers of tick bites and the importance of blood donation. 

“We are so lucky to be able to share Jonny’s story and advocate for awareness,” she wrote on Facebook. “Please, please do what you can to prevent tick bites, pay attention to and take possible symptoms seriously and speak up when you feel uncomfortable! And most importantly, please donate blood.”