A measles outbreak in Kansas has rapidly expanded, reaching 23 cases in under a week, according to information released by the state health department on Wednesday. The outbreak is suspected to have connections to similar cases in Texas and New Mexico, where more than 370 cases have been reported. Separately, in Ohio, a single case in Ashtabula County has now spread to nine additional people. Prior to these two significant clusters, the U.S. had already exceeded its measles case count for the entire year of 2024, as per the U.S. Centers for Disease Control and Prevention.
Kansas health officials alerted physicians on Monday to be vigilant and advised early measles vaccination for infants aged 6 to 11 months living in or near the affected counties. This recommendation deviates from the usual practice of administering the measles, mumps, and rubella (MMR) vaccine when children turn one year old. In the context of outbreaks, early vaccination serves as a preventive measure.
Previously, as of Friday, Kansas had documented 10 cases across three southwestern counties: Grant, Morton, and Stevens. The outbreak has since reached Haskell, Gray, and Kiowa counties. Data indicates that the majority of cases involve individuals under the age of 18. The first case in this current outbreak was recorded on March 13 in Stevens County.
In Ohio, there are currently 10 cases in Ashtabula County. Additionally, a visitor to Knox County has potentially exposed individuals in that area and several neighboring counties, according to the state health department. Ohio had experienced a significant measles outbreak in 2022, which resulted in 85 cases.
Ohio Department of Health Director Dr. Bruce Vanderhoff expressed regret over the spread, attributing the increase to ongoing measles activity in Texas, New Mexico, and other states. He emphasized the seriousness of the disease, describing it as potentially deadly, while noting that vaccination can largely prevent it. New Mexico reported 43 cases linked to the outbreak on Tuesday, while Texas had 327 cases. Oklahoma, reporting cases associated with Texas and New Mexico, has documented 9 cases so far.
Public health experts warn that the outbreak, which originated in Texas in late January, may persist for several months. Should it reach other unvaccinated communities across the U.S., the outbreak could last a year, jeopardizing the country’s status regarding the eradication of local transmission of measles—a vaccine-preventable disease. Communities are generally considered shielded from measles outbreaks if their MMR vaccination rate is 95% or higher. The MMR vaccine is a two-dose series, mandated for entry into public kindergarten, with a 97% effectiveness rate in protecting against measles.
In some Kansas counties experiencing the outbreak, vaccination rates are markedly lower than the suggested threshold. For instance, Morton County has an 82% vaccination rate, Stevens County 83%, Haskell County 58%, and Gray County 66%, based on data available for the 2023-2024 school year. Across Ohio, 89% of kindergartners were vaccinated against measles during the 2023-24 school year, data from the CDC reveals.
Jill Bronaugh, spokesperson for the Kansas state health department, highlighted the highly contagious nature of measles, indicating that further cases are likely to arise within the outbreak area and beyond, particularly among unvaccinated individuals.