By Nathaniel Ratnasamy, MD, Infectious Disease Specialist and Gina Bailey, BSN, RN, Infection Preventionist
Blanchard Valley Health System

There has been concern about measles cases in various parts of the country and a significant uptick worldwide. In the last few weeks, a total of 607 confirmed measles cases were reported by 22 states, including 11 cases in Ohio. Of the 607 confirmed US cases, 74 have been hospitalized, and three have died. According to the CDC, 2025 is already the third-most active year for measles since 2000.

Measles is among the most contagious infectious diseases; up to 9 out of 10 susceptible persons with close contact with a measles patient will develop measles. The virus is transmitted by direct contact with infectious droplets when an infected person breathes, coughs, or sneezes. The measles virus can remain infectious in the air for two hours after an infected person leaves an area.

The time from when a person is exposed to the measles virus and when symptoms start is typically 11–12 days. These symptoms may include fever, cough, stuffy nose, and red eyes. Then, there may be tiny white spots on the inside of the mouth known as Koplik spots - three to five days after initial symptoms, a rash of both flat and raised skin lesions begins on the head and face and then spreads downward to the neck trunk, arms, legs, and feet. Fevers may spike to more than 104◦ F.

Measles can cause severe health complications, including pneumonia, encephalitis, and death. One in five people with measles is hospitalized, one in 20 develops pneumonia, and one in 1,000 develops encephalitis. Measles, mumps, and rubella (MMR) vaccination remains the best way to protect against measles and its complications.

Measles was officially eliminated from the United States in 2000, meaning no measles were spreading within the country. This was accomplished by a very high percentage of people receiving the safe and effective MMR vaccine, introduced in 1963. The risk of measles remains low for most of the United States due to high immunization coverage and rapid case identification. 

The increase in U.S. cases is due to people returning from international trips with measles and an expanding outbreak among communities with low vaccination coverage. Among the 607 cases reported in 2025, 436 were among unvaccinated or under-vaccinated children under 19. The remaining cases were adults who were unvaccinated or had unknown vaccine status.

The Centers for Disease Control (CDC) recommends two doses of measles-containing vaccine: the first at age 12 - 15 months and the second at age 4- 6 years before school entry. Adults should also have received 1 or 2 doses (depending on risk factors), unless they have other presumptive evidence of immunity to measles. Note, a small number of adults who received the inactivated measles vaccine during childhood from 1963 through 1967 are considered unvaccinated and should receive at least one dose of MMR vaccine. For more information about MMR vaccination, talk to your health care provider or your local health department.