An ongoing measles outbreak in central Ohio has sickened 74 children since mid-October, resulting in 26 hospitalizations so far, Columbus Public Health reported (opens in new tab). There have been no reported deaths linked to the outbreak.
Between Jan. 1 and Dec. 8, 2022, the Centers for Disease Control and Prevention (CDC) (opens in new tab) received reports of 88 measles cases across the nation, meaning most can be attributed to the Ohio outbreak. By comparison, a total of 62 U.S. measles cases were reported to the CDC in 2020 and 2021 combined.
Of the children sickened in the Ohio outbreak, 69 out of 74 hadn't received any doses of the measles, mumps and rubella (MMR) vaccine, according to Columbus Public Health. Four children had received one dose of the vaccine out of the two recommended doses, although notably, "some cases may not have been eligible yet for the second dose due to age," the health department noted. The remaining child's vaccination status is unknown.
The CDC recommends (opens in new tab) that children receive their first MMR dose between 12 months and 15 months old and their second dose between 4 and 6 years old. Alternatively, the MMRV vaccine, which also guards against varicella (chickenpox), may be given following the same vaccination schedule. (If traveling overseas, however, a child may need to get vaccinated at a younger age than usual, the CDC notes.)
One dose of either vaccine is estimated to be 93% protective against measles, and two doses are 97% protective. That means there's a slim chance that vaccinated people can still become infected, but in these cases, they tend to have milder cases of the disease than unvaccinated people do, the CDC states.
In the current outbreak, 51 of the affected children, or 69%, are between 1 and 5 years old. Five of the children are between 6 and 17 years old, and 18 are younger than 1. In general, children younger than 5 face a high risk of complications from measles, according to the CDC (opens in new tab). These complications include ear infections, diarrhea and dehydration, as well as more-severe, potentially life-threatening conditions, such as pneumonia and brain swelling (encephalitis), the latter of which can lead to convulsions and changes in hearing ability and cognitive function.
Measles spreads through an infected person's coughs and sneezes, which release viral particles that can be inhaled or picked up from contaminated surfaces by other people. The incredibly infectious virus infects an estimated 90% of unvaccinated people who spend time near an infected person, and the virus can remain infectious and suspended in the air for up to two hours after the infected person exits the room, according to the CDC.
In general, measles symptoms begin one to two weeks after exposure; initial symptoms can include cough, runny nose, watery eyes and a fever higher than 104 degrees Fahrenheit (40 degrees Celsius). Then, white dots known as "Koplik spots" appear in the mouth, and a red, splotchy skin rash emerges on the face and then spreads to the neck, trunk, arms, legs and feet.
"There's no way of knowing which children will become so sick they have to be hospitalized," Columbus Public Health spokesperson Kelli Newman told CNN (opens in new tab). "The safest way to protect children from measles is to make sure they are vaccinated with MMR."
Adults without "presumptive evidence of immunity" — meaning a record of MMR vaccination or blood test results showing that they're immune to measles — are also recommended to get at least one dose of the vaccine, the CDC states (opens in new tab). Certain adults in this group should get two doses, including students at post-high-school educational institutions, health care personnel, international travelers and those who will be in other settings that pose a high risk for measles transmission.