A recent case of Powassan virus, a serious but uncommon tick-borne illness, has been identified in one of the youngest residents of Martha’s Vineyard, according to the family of the infant.
Lily Belle Sisco entered the world on June 30, weighing in at 7 pounds and 1.6 ounces. Her 6-year-old sister, Rose Sisco, was thrilled to welcome a little sister.
However, just a few weeks later, on July 24, Lily was rushed to Massachusetts General Hospital with a concerning and persistent fever of 102 degrees, which left doctors puzzled. Soon after, she started experiencing seizures and was diagnosed with viral encephalitis.
This past weekend, Lily’s mother, Tiffany Sisco, 32, discovered that a tick bite was behind her daughter’s sickness. Medical experts at Mass General and the U.S. Centers for Disease Control and Prevention confirmed that Lily has contracted Powassan, which is transmitted via bites from infected ticks, as Ms. Sisco shared in an interview.
Local public health officials announced the case was a preliminary finding and marked the second occurrence of Powassan on the Island in two decades. At just over a month old, the Sisco family believes Lily to be the youngest patient ever to contract the virus, and they are eager to spread awareness to prevent similar incidents.
“Please, check yourselves, your children, and your pets,” Ms. Sisco urged in a social media post to the community. “It was the tiniest nymph tick, barely the size of a needle tip. There were no rashes or noticeable bullseyes. If you experience fever, nausea, headache, confusion, or seizures after a tick bite, seek medical attention immediately.”
In a recent phone call from the hospital, Ms. Sisco recounted taking Lily and Rose for a brief walk on the West Tisbury bike path a week after Lily was born. Upon returning home, she noticed a tiny tick clinging to Lily’s ankle, which prompted a conversation with her husband, Marcus. They monitored Lily’s condition closely.
Within a week, Lily developed a fever and was taken to Boston for treatment. This was almost two weeks ago, and since then, she has been in a constant battle.
The infant has suffered brain injury from the infection and experienced more than 20 seizures in a single day, as per Ms. Sisco. She mentioned that Lily has been given strong sedatives to manage the seizures and is currently in stable condition. “She continues to amaze the doctors with her progress at MGH,” Ms. Sisco noted in her online updates.
The extent of her brain damage is still unclear, and further MRI scans will be necessary.
Lily’s case is quite rare for both Martha’s Vineyard and Massachusetts. There have only been three confirmed instances of Powassan this year in the state, and the last case on the Vineyard dates back to 2021.
No cure, vaccine, or specific treatment exists for Powassan. In severe instances, it can lead to brain swelling, seizures, and neurological issues. Unlike many tick-borne diseases, which often require several hours of attachment for transmission, Powassan can spread within just 15 minutes of a bite.
The Island has gained a reputation as a hotspot for ticks, with Martha’s Vineyard reporting the highest incidence of Lyme disease in the country. Additionally, cases of alpha-gal syndrome linked to lone star ticks have surged recently.
Yet Powassan remains relatively uncommon. According to tests from Tufts University and the Martha’s Vineyard Tick Program, only 1 to 2 percent of local nymph ticks are infected, which aligns with rates found in other areas of New England.
“Given that Powassan can be transmitted so swiftly—and the fact that there’s no treatment—preventing tick bites is essential,” stated Lea Hamner, an epidemiologist for Dukes County.
Tiffany Sisco emphasized the need for caution when spending time outdoors.
“Please check yourselves, your kids, and your pets,” she reiterated when sharing Lily’s situation. “This is a horrific experience, and no family should endure this because of a tick bite.”
The community has rallied around the Sisco family since Lily’s diagnosis. Relatives have initiated a fundraiser to assist with medical expenses, and they’ve already raised over $20,000.
“With medical costs and the loss of work, any help will support the family during this difficult time,” shared Marcus’s sister, Ashlee Moreis, on a fundraising page.
The support from the Vineyard community has been invaluable, according to the Siscos.
“The love and encouragement we’ve received has been incredible,” Ms. Sisco expressed. “I am truly thankful for everyone who has reached out.”
