Ohio has confirmed 45 measles cases so far this year, a total that took all of 2025 to accumulate, according to figures the Ohio Department of Health reported. Wayne and Trumbull counties recorded their first infections of the year as part of the state's third and still growing outbreak.
The trajectory is steep. A week before that count was published, the state health department had reported 15 cases for the year. Ten Ohio counties now have confirmed cases, with the largest burdens in Geauga County, Tuscarawas, Ashtabula, and Cuyahoga. Geauga has 13 cases, Tuscarawas eight, and Ashtabula and Cuyahoga seven each.
For families in northeast Ohio, the practical meaning is narrower than the statewide number suggests. Measles spreads through the air and can linger for up to two hours in a space an infected person has left. That makes county-level and exposure-site information more useful for household decisions than the state total, and it makes vaccination status the single variable that most determines individual risk.
The Numbers Behind Ohio's Third Outbreak
The state's year-over-year comparison shows how sharply the pattern has shifted. Ohio recorded one measles case in 2023, seven in 2024, and 45 in 2025. It matched that 2025 figure in early August of this year. The state's largest recent year was 2022, with 90 cases, most of them tied to an outbreak in central Ohio.
Five of the 45 infected people have required hospitalization, according to the state's infectious disease dashboard. Cases have ranged in age from an infant to a 32-year-old.
Ohio's third outbreak of the year was declared in late July, when the state reported four confirmed cases, three in Ashtabula County and one in Tuscarawas County. All four were unvaccinated. Earlier outbreaks were declared in Cuyahoga County in January and Franklin County in February. Health officials have linked the recent increase to exposure events in Sugarcreek and North Bloomfield, where infected people attended a horse sale on July 18.
An outbreak is defined as three or more related cases, which is why a state can have several concurrent outbreaks alongside unlinked individual cases.
Ohio in the National Picture
The state total sits inside a national count that has already passed last year's. In its most recent weekly update, the CDC put the national total at 2,465 measles cases for the year, compared with 2,289 for all of 2025. That is the highest annual total since 1991. All but 16 of this year's cases have been locally acquired, with the rest tied to international travel, and the agency is tracking 38 outbreaks, compared with 48 last year.
The demographic breakdown is consistent with what state-level data show. Twenty percent of 2026 cases involve children age 5 and under, and 68% involve children and young adults up to age 19. Seven percent of patients have been hospitalized nationally, down from 11% in 2025. Among all measles patients this year, 93% are unvaccinated or have unknown vaccination status. No measles deaths have been reported nationally in 2026, after three in 2025.
Pennsylvania, which borders Ohio, reported 57 new cases in a single week and 226 for the year.
The Vaccination Math That Drives Transmission
Measles is among the most contagious diseases known. Ohio health officials state that nine out of 10 unvaccinated people exposed to the virus will become infected.
Two doses of the MMR vaccine are approximately 97% effective against measles, and the state health department describes the vaccine as safe and effective. The CDC recommends a first dose at 12 to 15 months and a second at 4 to 6 years. In outbreak settings, a first dose can be given as early as 6 months, though that early dose does not replace the routine two-dose series.
That effectiveness figure explains why outbreak spread concentrates in specific communities rather than distributing evenly. Preventing sustained transmission requires roughly 95% community coverage, and clusters below that threshold can sustain chains of infection even when statewide coverage looks adequate.
Infants under 12 months, who are too young for routine vaccination, depend entirely on the immunity of people around them. That group carries elevated complication risk alongside adults over 20, pregnant people, and immunocompromised individuals.
Recognizing Exposure and Acting on It
Symptoms typically appear seven to 14 days after exposure. The illness begins with high fever, cough, runny nose, and red watery eyes. Koplik spots, tiny white spots inside the cheeks, may appear before the rash. The characteristic blotchy red rash usually starts at the hairline, moves to the face and upper neck, and spreads down the body, lasting five to six days.
An infected person can spread measles from four days before the rash appears through four days after, which is why exposure notification often reaches people days after the fact.
The most important practical instruction concerns how to seek care. Anyone who suspects measles should call the clinic or emergency department before arriving, because a waiting room can become an exposure site. Diarrhea and ear infections are common complications. The state health department notes that as many as one in every 20 children with measles develops pneumonia, the most common cause of measles death in young children, and that brain swelling and neurological damage can occur.
Families can verify MMR status through their pediatrician, primary care provider, or state immunization records. Uninsured and underinsured children qualify for free MMR vaccination through the Vaccines for Children program, and most insurance plans and Medicaid cover the vaccine at no cost. Adults with uncertain histories can safely receive a dose. MedicalDaily has published a guide to finding free and low-cost MMR vaccination across the country, and has tracked this year's record national total.
The Ohio Department of Health updates its dashboard regularly, and the CDC publishes national counts weekly. A CDC committee is reviewing U.S. measles elimination status this month and will forward its findings to the Pan American Health Organization, which is expected to announce a decision in November.
Key Questions Answered
How many measles cases has Ohio confirmed this year? Forty-five, matching the state's total for all of 2025. Ohio had seven cases in 2024 and one in 2023.
Which counties are affected? Ten counties have confirmed cases. Geauga has the most with 13, followed by Tuscarawas with eight and Ashtabula and Cuyahoga with seven each. Wayne and Trumbull counties reported their first cases of the year.
How many people have been hospitalized? Five of the 45 confirmed cases in Ohio have required hospitalization. Cases have ranged in age from an infant to a 32-year-old.
How contagious is measles? Ohio health officials say nine out of 10 unvaccinated people exposed will become infected. The virus can remain in the air for up to two hours after an infected person leaves a space.
How well does the vaccine work? Two doses of MMR are approximately 97% effective. Nationally, 93% of 2026 measles patients are unvaccinated or have unknown vaccination status.
What should someone do if they think they have measles? Call the clinic or emergency department before going in. Arriving unannounced can expose others in a waiting room. Early symptoms include high fever, cough, runny nose, and red watery eyes, followed by a rash.
Where can families get the MMR vaccine? Through a pediatrician, primary care provider, pharmacy, or local health department. Uninsured and underinsured children qualify through the Vaccines for Children program, and most insurance plans and Medicaid cover it without cost sharing.
