Tiffany Sisco, who declined to be interviewed by ABC News, told Boston ABC station WCVB that she found a tick on her 5-week-old daughter Lily Belle Sisco during an outdoor walk, and despite removing it, she noticed Lily developed symptoms a week later.

A Massachusetts newborn is suspected of having Powassan virus, a rare but serious tick-borne illness likely transmitted by a tick bite during a family walk.