Why Doctors Still Worry About Measles

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The Checkup

My grandmothers had measles. Your grandmothers had measles. In medicine, it is taken for granted that all people born before 1957 had measles, whether they remember it or not.

Grandmothers invariably were invoked on questions of measles back when I was doing my residency in the 1980s in Boston. When there was a child in the emergency room with a truly striking and scary rash, a senior attending physician would stride in, look at the child, and announce something like, “Your grandmother could diagnose measles from across the room!”

Nowadays, pediatricians worry that we’ve lost our collective memory and therefore some of our healthy fear of the disease and its serious complications — at least until an exposure happens and people start to panic.

Indeed, measles is a disease with a very specific character, and it still infects and kills children across the world. And a study presented in October suggested that one of the most feared later complications of measles is actually more common than we knew, and while it’s still rare, it reminds us of the urgency of protecting young children.

Researchers reviewed all the cases in California from 1998 to 2016 of subacute sclerosing panencephalitis (SSPE), a degenerative brain disease which occurs years after measles infection, but is still clearly linked to the virus and the body’s reaction to it. They found that those children who had had measles at less than 12 months old had a much higher risk of developing this fatal complication than had previously been reported.

“To our surprise, it was higher than generally recognized,” said Dr. James D. Cherry, one of the authors of the study, and a distinguished research professor in pediatric infectious diseases at the University of California, Los Angeles.

We learned about SSPE in medical school as a serious but very rare development that occurred after 1 in 100,000 cases of measles. In the California study, they found 17 such cases, and then traced those that they could back to the measles cases reported during the relevant years, many of them in an outbreak in 1989-90.

When they extrapolated out from the relationship between the cases of measles and the cases of SSPE, they found that for children under a year, the rate was 1 in 600. To doctors, that no longer seems like a rare event — you would get one such case for every 600 young children who got measles. Though thanks to vaccines, in most years there are far fewer than 600 measles cases in the United States. This year, the Centers for Disease Control and Prevention recorded only 62 as of Nov. 5.

But it is still something to worry about for a disease which, without vaccination, infects whole populations. The complications start an average of eight years after the infection. “Nobody would connect it with measles,” Dr. Cherry said.

SSPE begins with symptoms like poor performance in school and subtle behavioral changes, Dr. Cherry said, and then progresses over the course of months to seizures. And then the children deteriorate further: “They lose a lot of other functions, and then they end up needing tube feeding and in a vegetative state.”

Measles also causes a form of encephalitis in some children right at the time of infection, and it can harm and kill children in other ways.

Measles encephalitis is what killed Olivia, the 7-year-old daughter of the writer Roald Dahl, in 1962, before the vaccine was available; he wrote a passionate letter to other parents two decades later, imploring them to get their children immunized.

Those children who do die from measles are often killed by other infections, especially pneumonia. Measles was “the first immunosuppressive virus described, long before H.I.V.,” said Dr. William J. Moss, the deputy director of the International Vaccine Access Center and a professor of epidemiology at Johns Hopkins Bloomberg School of Public Health. Epidemiologists have attributed any nontraumatic death in the first 30 days after measles to the disease, he said, but more recent evidence suggests that the risk period may be longer than that.

The virus is so contagious because it can spread through airborne transmission, but also because the viral particles stay in the air or on surfaces for a long time. If you are not immunized (as children under a year are not) or if you only had one dose and you are in the 5 percent of people who don’t respond to that first dose, you can get infected by being on the bus, or in the pediatrician’s waiting room, even after the sick person has left.

“Two of the most contagious viral infections are smallpox and measles,” said Dr. Anne Gershon, the director of the division of pediatric infectious diseases at Columbia. Before they develop that characteristic measles rash, children have high fever and respiratory symptoms, and they are therefore at their most infectious before the disease has been identified. “In the early stages of the disease there’s a lot of coughing, runny eyes and nose, but you don’t think of isolating somebody till the rash comes out and after that they’re gradually less contagious,” she said.

Dr. Matt Zahn, the medical director for epidemiology for the Orange County Health Care Agency oversaw the public health response in Orange County to the Disneyland measles outbreak which began in December 2014. He also took care of kids who were sick in the hospital. “The fever is high, there’s a lot of nasal congestion and cough, these kids are miserable, they feel rotten,” he said. “A kid with measles is not a smiling child who has a mild rash.”

The anti-vaccine movement has been known to cite sitcom episodes as evidence that measles wasn’t a serious disease; sure, the Brady Bunch kids got red spots. In fact, the measles rash is quite startling, with red patches that tend to merge as they cover the skin.

The first dose of measles vaccine, which we currently give at 12 months, leaves 95 percent of children immune, but that’s not enough for effective herd immunity with a disease this contagious. That’s the reason for the second dose of vaccine, which is now given at 4 years old, but may be moved up.

We passed a kind of milestone last September when the Americas were declared officially free of endemic measles cases, an epidemiologic honor meaning that the only cases seen in this hemisphere since 2002 were from imported virus. But it’s a fragile victory, as everyone who works with infectious diseases continues to worry, since the disease is still around in many other parts of the world, and people travel back and forth, and there is a significant population of unprotected young children in this country, largely thanks to parental anxiety about vaccination. Even more worrisome, according to some experts, is the population of children whose parents refused the vaccine a couple of decades ago; measles can be a bad disease in children, but it can be even more dangerous in young adults.

Dr. Zahn said of the California outbreak: “What contained this virus in this event was that while we have relatively lower immunization rates in some pediatric populations in our community, our adult immunization rates were high, well over 95 percent,”

Unvaccinated children might get sick, but the virus had no place to go in their families because the adult population had grown up in an era when everyone got vaccinated. If there’s another outbreak some years down the line, we may have many more unvaccinated adults. “It won’t affect how you start the fire, but how long that fire burns in the community may be very different,” he said.