Measles Cases On The Rise Across The U.S.: What To Know In PA

PENNSYLVANIA — U.S. measles cases are nearly triple what they were last year, including up to 9 cases in Pennsylvania, according to data released Friday by the Centers for Disease Control and Prevention.

With five months left to go in the year, 26 states and the District of Columbia have reported 188 cases of measles, about half of which (49 percent, or 93) were severe enough to require hospitalization, mostly among people under the age of 5.

Last year, the nation saw 58 measles cases in four outbreaks. This year, there have been 13 outbreaks, the largest of them traced to a migrant shelter in Chicago in March in which 60 illnesses have been linked.

Seven states — Massachusetts, Michigan, Minnesota, New Hampshire, New York, Oregon and Vermont — joined the growing list of states with measles outbreaks in the past month, according to the CDC. In Massachusetts, the case was the first in three years.

Earlier this year, Pennsylvania health officials confirmed seven cases of measles diagnosed in the state between Dec. 6, 2023, and Jan. 5, 2024. Six of these cases were reported in southeastern Pennsylvania and were epidemiologically linked. An additional unlinked case was reported in north-central Pennsylvania, state health officials said.

Since then, at least two outbreaks were reported in Montgomery County, though it’s unclear how many people were sickened.

The CDC said the current uptick in cases is due to an increase in vaccine hesitancy since the COVID-19 pandemic, as well as a global uptick in measles cases.

About 85 percent of U.S. measles cases this year were among people who haven’t been vaccinated or had an unknown vaccination status, and 10 percent were among people who had taken only one dose of MMR (measles, mumps and rubella) vaccine.

In some U.S. communities, the number of people protected against measles by the vaccine has fallen below the 95 percent coverage level needed to prevent measles outbreaks.

In Pennsylvania, 94 percent of kindergarteners in the 2022-23 school year were up-to-date on their MMR vaccinations, according to CDC data. Nationwide, 93 percent of kindergartners that year had received two doses of MMR vaccine, compared to 93 percent in the 2019-20 school year, the data shows.

Children in Pennsylvania are required to receive two doses of the MMR vaccine before they enter kindergarten, according to the state Department of Health. The only exemptions are for children with religious reasons.

Measles was declared eradicated from the United States in 2000, a status threatened by a large measles outbreak in 2019, which resulted in 1,200 cases, mostly associated with outbreaks in Orthodox Jewish communities in New York. The 2024 measles outbreak is the highest since then.

Before the vaccine became available in 1963, between 3 million and 4 million people were infected every year, with about 400 to 500 of them dying.

Measles is highly contagious. A sick person can spread it to 90 percent of the people in close contact if they are not immune, and the virus can remain in the air for up to two hours after an infected person leaves.

Common symptoms include a high fever, cough, pink eye (conjunctivitis), runny nose, white spots in the mouth, and a rash that typically starts on the face and spreads downward to the feet.

Between one and three of every 1,000 children infected with measles die from complications of measles, which can include pneumonia and swelling of the brain.