4 things you should know about measles amid an uptick in cases

(WGN Radio/Nexstar) — The U.S. is seeing a rash of measles cases, with more than three dozen cases reported across 17 states already this year, according to the Centers for Disease Control and Prevention. This comes two months after the agency warned clinicians to remain alert for measles cases.

So far this year, 45 cases have been reported in Arizona, California, Florida, Georgia, Illinois, Indiana, Louisiana, Maryland, Michigan, Minnesota, Missouri, New Jersey, New York City, Ohio, Pennsylvania, Virginia, and Washington, CDC data shows.

Among the most notable cases are those reported in Chicago, where the CDC said it’s “sending a team of experts to support the local response.”

As of Monday, the Chicago Department of Public Health (CDPH) has confirmed five measles cases in the city, with four at a migrant shelter in the Pilsen neighborhood. The two most recent cases were confirmed in adults at the shelter who are in stable condition.

“If a measles outbreak continues for a year or more, the United States could lose its measles elimination status,” the agency notes on its website.

The U.S. previously eliminated measles thanks to widespread vaccination against the disease in 2000. But, in the years since, “we’ve had certain years where we’ve had increasing cases,” Dr. Bessey Geevarghese, a pediatric infectious disease specialist at Northwestern Medicine Central DuPage Hospital, told Lisa Dent of WGN Radio.

Young children are especially at risk since the Centers for Disease Control and Prevention recommends waiting for the first vaccine dose until 12 to 15 months of age.

This may leave you wondering — should you be concerned about the virus?

“I think we’re going to continue to see increased cases,” Geevarghese said. “So I think we really need to be vigilant to make sure that children and even adults are up to date with their vaccine.”

You can listen to the full interview below.

What to know about the measles vaccine

“I think, since the pandemic, there’s been a lapse in keeping up to date with vaccines,” she explained. “There’s also been a big movement from the anti-vaccine groups into choosing whether you decide or not to have vaccines. So I think there’s a lot of different contributors to the lapse in vaccination rates in our kids.”

Geevarghese said schools have allowed more exemptions when it comes to the measles vaccine.

Measles vaccines have been available since the 1960s, and states have largely required children to have them before attending school. That means there’s a good chance you’ve already been vaccinated against measles, and because those vaccines are more than 90% effective at preventing the disease — 97% if you got two doses of an MMR (measles-mumps-rubella) vaccine, 93% if you got one, according to the CDC — you are, most likely, safe from it.

You may also be considered “protected” if you’ve already had measles, a laboratory has confirmed you’re immune or you were born before 1957. Geevarghese explained that antibody testing can determine if you have “evidence of protective immunity” against the virus, and if you don’t, you can get vaccinated.

Those who are not immune have a 90% chance of becoming infected if they are in a room with someone diagnosed with measles, Geevarghese said. Droplets that can spread measles can remain in the air for up to two hours, she adds.

“The other hard thing with measles is that the incubation time is pretty long,” she continued. “So on average, it’s about 12 to 14 days before you’re presented with symptoms after being exposed.”

What are the symptoms of measles?

Measles is well-known for causing a rash, but there are several other symptoms to be on the lookout for in case you or your child are exposed. According to the CDC, that includes a high fever that may spike to more than 104°F, a cough, a runny nose, and red, watery eyes. In the days after symptoms begin, you may notice tiny white spots appear inside your mouth. These are known as Koplik spots.

Three to five days after symptoms begin, the CDC says a rash breaks out. This usually looks like flat, red spots on the face that spread down to the neck, arms, legs, trunk, and feet.

If you believe you or your child has contracted measles, you should contact a healthcare provider immediately.

What are the complications of measles?

“Measles can be dangerous to young kids,” Dr. Jim Adams, Chief Medical Officer of Northwestern Medicine, previously told WGN Radio. “It’s miserable for everybody, it’s really preventable, and it’s hyper infectious.”

One in five people who get the virus are hospitalized, CDC data shows. Some children with measles suffer from encephalitis, or a swelling of the brain, that can cause deafness or an intellectual disability. Pregnant women who have not been vaccinated may give birth prematurely or have a low-birth-weight baby.

As many as 1 in 20 children who contract measles develop pneumonia, the most common cause of death from the disease, according to the CDC. Out of 1,000 children who get measles, nearly one to three on average will die from respiratory or neurologic complications.

There have been no reported deaths caused by measles, according to Geevarghese.

Is there a measles outbreak in the U.S.?

Despite the number of cases so far reported this year — only 13 fewer than we saw in all of 2023 — the CDC has not yet declared a measles outbreak in the U.S. The agency says outbreaks are declared “when the number of cases reported in an area is higher than the expected number of cases.”

The last reported measles outbreak in the U.S. was in 2019 when 1,274 cases were confirmed in 31 states, the most since 1992. According to the CDC, the majority of those cases were among people who had not been vaccinated.

The Hill’s Joseph Choi contributed to this report.