NY children's hospital measles exposure triggers alerts. What parents should know

A measles exposure at a children's hospital last week on Long Island triggered public health alerts as New Yorkers braced for further spread of the highly contagious virus during the spring holiday season.

News that an unvaccinated child infected with measles visited the Cohens Children’s Medical Center underscored concerns that the ongoing global surge in measles posed a unique risk in New York, which has several religious groups with low vaccination rates.

As families gathered for religious holidays this spring, health officials urged anyone with symptoms of measles —fever, rash, cough, conjunctivitis or runny nose — to contact a health provider before seeking care, which can help prevent the virus' further spread.

What are Koplik spots?

Tiny white spots, called Koplik, spots may appear inside the mouth two to three days after initial measles' symptoms begin, CDC says.

Three to five days after symptoms begin, a rash breaks out. It usually begins as flat red spots that appear on the face at the hairline and spread downward to the neck, trunk, arms, legs, and feet. At this point, the fever may spike to more than 104 degrees.

Public health: Will 2024 measles outbreak hit Finger Lakes, Hudson Valley? What we know now in NY

How does measles spread?

The measles virus is transmitted via the misty droplets that come when an infected person coughs, sneezes and even breathes. The virus can live up to two hours in the air and on surfaces in a room where an infected person has been.

Someone infected can transmit the disease from four days before to four days after a flat, itchy, red rash shows up. Measles symptoms may not appear for a week to three weeks after exposure.

How dangerous is measles?

Complications from measles include pneumonia, brain damage, deafness, and death.

It can be especially dangerous for babies, young children and pregnant women who haven't had the virus. People with immune system problems are also at heightened risk.

How effective is the measles vaccine?

Very effective. One dose of measles vaccine is about 93 percent effective at preventing measles if exposed to the virus. Two doses are about 97 percent effective.

Could someone fully vaccinated still get measles?

Very few people, about three out of 100, who get two doses of measles vaccine will still get measles if exposed to the virus.

Experts aren’t sure why. It could be that their immune systems didn’t respond as well as they should have to the vaccine.

Still, fully vaccinated people who get measles are much more likely to have a milder illness.

Fully vaccinated people are also less likely to spread the disease to other people, including people who can’t get vaccinated because they are too young or have weakened immune systems.

Do people need a booster vaccine?

No. CDC considers people who received two doses of measles vaccine as children according to the U.S. vaccination schedule protected for life, and they do not ever need a booster dose.

Still, as life expectancy continues to increase, should people entering their 80s and 90s be concerned about the effectiveness of a vaccine that they may have gotten almost a century before? A doctor can test for immunity through a blood test.

"If a patient feels like they really need it, they should speak with their doctor first, but for most people, getting another dose is very safe," Dr. Ashwin Jathavedam, an infectious disease specialist at Englewood Health, told USA TODAY Network.

How many measles cases in NY?

As of March 21, 2024, a total of 64 measles cases were reported in the U.S. so far this year, including two in New York City and one on Long Island.

Concerns about the 2024 measles outbreak, in part, stemmed from the fact the U.S. case count already surpassed the annual total for 2023. The worst outbreak in the past two decades came in 2019, when nearly 1,300 cases hit the nation with New York as the disease epicenter.

What is roseola rash?

Roseloa, also known as sixth disease, is unaffiliated with measles, but it causes rashes most commonly in infants and children, 1 to 5 years.

This illness is caused by a virus and results in some symptoms that overlap with measles, such as fever and cough. It usually isn't serious, and it goes away on its own in a week or so. Treatment includes cool cloths and medications to reduce fever, and patients suffering from a high fever over 103 degrees should call a health provider, according to CDC and the Mayo Clinic.

Scott Fallon of USA TODAY Network contributed to this report.

This article originally appeared on Rockland/Westchester Journal News: NY measles exposure at children's hospital: What parents should know