A previously healthy 11-month-old baby living in Washington state suffered a stroke weeks after contracting a mild case of chickenpox, which he most likely caught from his older, unvaccinated siblings, according to a recent report in the Journal of Pediatrics.
Stroke is a rare but recognized complication of chickenpox. It occurs when the chickenpox virus — varicella zoster — triggers inflammation in the brain, which can lead to a restriction in the brain’s blood supply.
As background information in the report notes, research has found that children are at a fourfold increased risk of stroke for six months after they’ve had chickenpox. In fact, the median time between the onset of chickenpox and a related stroke is 16 weeks.
No increased risk of stroke has been observed in children who have been vaccinated against chickenpox.
At 11 months, the baby in the Journal of Pediatrics report had been too young to receive the varicella vaccine. The first shot is usually given to children soon after they turn a year old.
To avoid being exposed to the easily contagious viral infection, the boy had to therefore rely on “herd immunity” — the hope that most of the people living around him in his community had been vaccinated.
But he did not have that herd immunity, even in his own home, for his siblings had not been vaccinated.
This case study underscores the importance of getting every child vaccinated in a timely manner against childhood diseases.
A weakened right side
The authors of the case study — a team of doctors at Seattle Children’s Hospital at the University of Washington — write that the boy’s mother first became concerned when she woke her son from his afternoon nap and noticed his right arm and leg appeared weak. She took the boy to an urgent care center, where doctors observed that the boy had lost significant strength and movement along the entire right side of his body, including his face.
The child was then quickly transferred to Seattle Children’s Hospital, where brain imaging revealed that he had experienced a stroke. While asking the mother about the boy’s medical history, the doctors learned that both he and his older siblings had been ill with chickenpox two to three months earlier. The mother said the boy’s case had been mild — just a few scattered “spots,” or blisters. A blood test confirmed the diagnosis.
The boy spent 10 days in the hospital, receiving intravenous drugs and other treatment. His muscle weakness improved both at the hospital and later at home, but follow-up brain imaging revealed that he is likely to have some kind of permanent neurological damage.
Prevention is key
The varicella vaccine is 90 percent effective at preventing chickenpox, health officials stress. Even when people who are vaccinated get the disease, the symptoms — a blister-like rash, itching, tiredness, and fever — tend to be milder.
Before the varicella vaccine was developed, about 4 million Americans, mostly children, came down with chickenpox each year. Of those, more than 10,000 were hospitalized, and 100 to 150 died.
Two doses of the varicella vaccine are recommended for children, the first at the age of 12 to 15 months, and the second at the age of 4 to 6 years.
Adults should also make sure they have been fully immunized against the disease.
Minnesota had 432 confirmed cases of chickenpox in 2017, up from 336 the year before, according to the Minnesota Department of Health. As of Sept. 6 of this year, state health officials have identified 177 probable or confirmed cases, mostly in the Twin Cities Metropolitan Area.
FMI: You’ll find the case study report on the Journal of Pediatrics website.