Indiana has confirmed 15 measles cases this year across three counties, an increase from the state’s first two cases reported in early August. The Indiana Department of Health’s September 17 update lists six cases each in Switzerland and Wayne counties and three in Parke County. The totals are provisional and may change as investigations continue.
The geographic spread is the practical development for residents and clinicians. Indiana’s August 5 health alert identified the first two laboratory-confirmed cases in Parke County adults and said those patients had been isolated while infectious. Since then, the state count has grown by 13 cases and expanded to two additional counties.
Indiana requires health-care providers, hospitals and laboratories to report suspected measles immediately. The state alert says testing should be considered when a patient has a generalized rash, fever of at least 101 degrees and cough, runny nose or conjunctivitis, along with a relevant exposure risk during the previous 21 days. Providers are instructed to contact the state before using the Indiana public-health laboratory.
Why early notice matters
Measles spreads through the air and can remain airborne for up to two hours after an infected person leaves a space. The Centers for Disease Control and Prevention says as many as nine in 10 unprotected people who have close contact with an infected person may become infected. Symptoms typically include high fever, cough, runny nose, red or watery eyes and a rash.
People with measles can transmit the virus from about four days before the rash appears through four days afterward. Indiana advises anyone who develops compatible symptoms after an exposure to call a health-care facility before arriving, allowing staff to prepare airborne-infection precautions and reduce exposure to other patients. Suspected patients should remain home except when medical care is necessary.
Vaccination remains the principal preventive measure. The CDC recommends two MMR doses for children, ordinarily at 12 to 15 months and again at ages 4 to 6. Adults generally need at least one documented dose, while some higher-risk adults need two. The vaccine is about 93% effective after one dose and 97% effective after two, according to CDC.
For an unprotected person with a known exposure, Indiana’s clinical guidance says an MMR dose within 72 hours or immune globulin within six days may prevent illness or reduce its severity, depending on age and health status. Public-health officials should guide those decisions.
The increase comes during a national measles resurgence. The CDC’s September 18 national update reports 3,471 confirmed cases in 2026 across 47 jurisdictions, with 39 outbreaks and 95% of cases linked to outbreaks. State and federal counts can differ because they are updated on different schedules.
Indiana residents can check the state measles page for updated county counts and use MyVaxIndiana to review immunization records. The immediate steps are to verify vaccination status, monitor for symptoms for 21 days after a known exposure and call ahead before seeking in-person care if measles is suspected.
