PHILADELPHIA (KYW Newsradio) — The city's Department of Public Health on Monday announced that a cluster of measles cases has grown to eight people, including at least five children. One of the country's leading virology experts explains why an outbreak in Philadelphia causes him serious concern.
"It's a shame that it's the most vulnerable among us — the children — who invariably have to suffer our ignorance," says Children's Hospital of Philadelphia pediatrician Dr. Paul Offit.
Measles is easily preventable through vaccination, but according to the health department, all eight cases are in people who had no immunity to the virus.
"We eliminated measles in the United States by the year 2000," said Offit said. "It's coming back, and I think the reason that it's coming back is we let our guard down."
All 50 states require specific vaccinations for kids before they can enroll in public schools. Every state also allows for exemptions for medical reasons. Some 45 states grant religious exemptions. Pennsylvania is one of 15 states that allow exemptions because of philosophical or strong moral or ethical convictions.
According to the CDC, exemptions for those required vaccines has hit a record high for American kindergartners.
A skepticism of vaccine science emerged during the COVID-19 pandemic — a time fueled by misinformation, says Offit. "Because I think that when we eliminated measles, sadly, we also eliminated the memory of measles. We don't remember how sick this virus can make us."
Since then, the immunization rate has dropped from 95% to 93%, according to the CDC. And that is why the highly contagious virus is able to make a resurgence, said Offit.
The health department is tracking the progress of the outbreak and posting regular updates online. They say someone, while outside of the United States, picked up the disease. In early December, that person went to CHOP, exposing three people, who later tested positive for measles. One of those three people attended a Philadelphia day care. Two days later, two kids from that day care were hospitalized with measles.
"When measles would come into this country from other countries, it wouldn't spread from one American child to another," said Offit. "That's not true now."
In all, the health department has reported eight cases: the first patient, four people at the day care and three people exposed at the hospital.
"When you're talking about that percentage of kids immunized for a highly contagious disease like measles, which is the most contagious of the vaccine-preventable disease, you really need to be at about the 95% range to stop spread."
Measles has a "contagiousness index" of 18, Offit said — "meaning, if I have measles and I go about my normal day, I will infect 18 people, assuming they're all susceptible to disease. COVID and flu are sort of in the 2 to 4 range — so, it's much more contagious than those diseases."
According to the health department:
—About 90% of people with close contact to an infected person will get measles if they're not vaccinated.
—About 1 in 5 unvaccinated people who gets measles in the United States is hospitalized.
—The most common cause of death in young children with measles is pneumonia. About 1 in 20 kids with measles will get pneumonia.
Offit says he expects to see more cases to emerge — "and we'll get to the point where children in this country will once again start dying from measles. And when that happens, I think then maybe we'll finally wake up."
