The Vineyard’s newest case of Powassan virus, a serious but rare tick-borne illness, was found in one of its youngest residents, according to the infant’s family. 

Lily Belle Sisco was born on June 30, weighing 7 pounds and 1.6 ounces. Rose Sisco, age 6, was over the moon about having a little sister. 

Tiffany Sisco is now urging people to take precautions after her daughter's diagnosis.

Courtesy of Tiffany Sisco

Tiffany Sisco is now urging people to take precautions after her daughter's diagnosis.

Courtesy of Tiffany Sisco

Less than a month later, on July 24, Lily was flown to Massachusetts General Hospital with a persistent 102-degree fever that initially baffled doctors. She later began to have seizures and it was determined she had viral encephalitis. 

Over the weekend, Lily’s mother Tiffany Sisco, 32, learned the culprit behind the maladies: a tick bite. 

Medical professionals with Mass General and the U.S. Centers for Disease Control and Prevention determined Lily has Powassan, a rare viral infection transmitted by the bite of an infected tick, Ms. Sisco said in an interview with the Gazette this week.

Island public health officials announced the preliminary case on Monday, and said it was the second on the Island in 20 years. Lily is just over one month old, and the Sisco family said she is the youngest patient in the world to ever contract Powassan, and they are hoping to get the word out so a case like their daughter’s is never repeated. 

“Please, please check yourselves, your children and your pets,” Ms. Sisco wrote in a message to the Island community on social media. “It was the tiniest nymph tick the size of a needle tip. No rash or bullseye was detected. If you develop a fever, nausea, headache or confusion, loss of coordination, speech difficulties and or seizures after [a] tick bite, seek medical attention asap.” 

In a phone interview from the hospital on Monday, Ms. Sisco said she took Lily and Rose out for a 15-minute walk on the West Tisbury bike path near her home about a week after Lily was born. When Ms. Sisco noticed a tiny tick on Lily’s ankle when she got home, she called her husband Marcus concerned and they monitored Lily’s health.

About a week went by before her fever developed and she was brought to Boston for treatment. That was just under two weeks ago, Ms. Sisco said, and Lily has been fighting ever since. 

The infant has suffered brain damage caused by the infection and had more than 20 seizures in one day, according to Ms. Sisco. Lily was given heavy sedatives to deal with the seizures, and is in stable condition, Ms. Sisco said. 

“She is still fighting daily at MGH and continuing to leave the doctors speechless with her progress,” Ms. Sisco wrote in her online chronicles about Lily’s battles. 

Lily Sisco is believed to be the youngest person to contract Powassan.

Courtesy of Tiffany Sisco

Lily Sisco is believed to be the youngest person to contract Powassan.

Courtesy of Tiffany Sisco

The extent of brain damage is not known yet and further MRIs will be needed.

Lily’s case is a rarity on both Martha’s Vineyard and in the state. There have been three confirmed cases of Powassan in Massachusetts this year, and the last confirmed case on the Vineyard was 2021.

There is no cure, vaccine or specific treatment for Powassan, which in severe cases can cause brain swelling, seizures and neurological complications. Unlike other tick-borne illnesses where the arachanids may need to be attached to a victim for several hours for a disease to be transmitted, Powassan can be passed along within 15 minutes of a tick bite.

The Island has a reputation as a tick hotspot. The Vineyard claims the highest rate of Lyme disease in the country and has seen cases of alpha-gal syndrome connected with lone star ticks skyrocket in recent years. 

Powassan still remains relatively rare. During lab tests of more than 3,500 nymph ticks, Tufts University and the Martha’s Vineyard Tick Program found between 1 and 2 per cent of Vineyard ticks are infected, similar to other parts of New England.

“Because Powassan virus can be transmitted so quickly — and because there is no treatment — the most effective protection is to prevent tick bites in the first place,” said Lea Hamner, a contract epidemiologist for Dukes County. 

Ms. Sisco urged people to take precautions when going outside.

“Please check yourselves, your kids and your pets,” she wrote when sharing the news of her daughter’s case. “This is horrible and no family should ever have to go through this over a bug bite.” 

Since announcing Lily’s diagnosis, the Island community has rallied around the family. Relatives have started to raise money to help with the medical bills, already garnering more than $20,000 in donations. 

“Between medical costs and not working, anything will help to support [the family] on this tough journey,” Marcus’s sister Ashlee Moreis wrote on a gofundme page.

The support from Vineyarders means the world, according to the Siscos.

“The love and support of the community has been amazing,” Ms. Sisco said. “I’m really grateful to everybody who has reached out.”