Clinicians there performed tests, including a brain MRI that showed clear signs of a serious infection. The testing showed that the baby didn’t have meningitis, an infection in the tissues surrounding the brain. But he did have an unusual pattern of inflammation in the very deep parts of his brain.
Doctors didn’t know what was causing the inflammation. But the parents said that two weeks earlier, they had pulled a tick off the baby’s knee, and that the tick had been there for two to three hours. The parents told doctors that the tick was probably carried in on someone's clothing who was out hunting, who then held the baby before changing clothes.
Nicholas Bennett was the infectious disease specialist who treated the boy when he was brought to the hospital in early November. It was too late in the year for the infant to have been exposed to mosquitoes, which can transmit viruses that cause encephalitis, or inflammation of the brain.
Instead, the clues suggested a rare tick-borne illness known as Powassan virus disease. Bennett had trained in Upstate New York, where doctors had seen cases of the illness, which can be fatal in up to 10 percent of cases. He also had read studies saying that the disease had been found in ticks in Connecticut.