Health officials in Kansas today reported six more measles cases, bringing the total in the state's growing outbreak to 32 and adding to the national total.
The outbreak, which began on March 13, is centered in eight counties in the southwestern corner of the state, according to the update from Kansas Department of Health and Environment (KDHE). Of the 32 case-patients, 27 are unvaccinated, 2 are pending verification, and 1 has unknown vaccination status. Twenty-six cases are in children and adolescents under 17. One patient has been hospitalized.
KDHE officials say that because of the highly contagious nature of measles, additional cases in the outbreak area are likely.
Kansas is one of 21 US states that have reported measles cases in 2025, which has now seen more than twice as many cases as all of last year, when 285 cases were reported. It's only the third year since 2000, when measles was declared eliminated in the United States, with more than 500 cases. At the current rate, it appears that the number of US measles cases will likely surpass the 1,274 reported in 2019.
The vast majority of measles cases have occurred in Texas, where an outbreak that originated in an unvaccinated Mennonite community in the western part of the state has topped 500 cases, and resulted in two deaths in unvaccinated children.
Patients in Colorado, Hawaii unvaccinated
Yesterday officials in Colorado confirmed its third measles case this year, in an adult with unconfirmed vaccination status.
"This case does not appear to be linked to the other cases reported in Colorado and the individual did not travel outside of Colorado, which leaves open the possibility of community transmission," Rachel Herlihy, MD, MPH, state epidemiologist and deputy chief medical officer at the Colorado Department of Public Health and Environment, said in a press release. "We urge Coloradans to monitor for symptoms if they may have been exposed, and to make sure they are up to date on their MMR vaccinations."
In Hawaii, officials with the Hawaii Department of Health (DOH) confirmed a case of measles in an unvaccinated child under 5 years of age on Oahu that appears to be linked to recent international travel. A household member with similar symptoms is also being evaluated for a possible measles infection.
According to data from the Centers for Disease Control and Prevention (CDC), 97% of US measles cases in 2025 have been in individuals who are unvaccinated or have unknown vaccination status. While two doses of the MMR vaccine are 97% effective at preventing measles, growing vaccine hesitancy in the United States has resulted in a decline in uptake of the vaccine.
Data reported by the CDC last year show that during the 2023-2024 school year, MMR vaccine coverage among US kindergartners fell to 92.7%. But a new report from healthcare analytics company Truveta suggests that figure is even lower, finding that only 80.4% of US children had received both MMR doses by age 6 in 2024. Maintaining measles elimination status requires vaccination coverage of 95% or higher.
Outbreaks in Mexico, Canada
Meanwhile, US neighbors to the north and south are also dealing with growing measles outbreaks.
According to the most recent surveillance report from the Canadian government, 615 measles cases have been reported in six jurisdictions in Canada as of March 22. Of these cases, 538 are linked to an outbreak that began in New Brunswick in October 2024. Ninety-three percent of the case-patients are either unvaccinated or have unknown vaccination status.
From 1998 to 2024, Canada averaged 91 measles case a year, with spikes in 2011 (751 cases) and 2014 (418).
Officials with the Macomb County Health Department Michigan said last week that an adult county resident with a confirmed measles infection recently traveled to Ontario.
In Mexico, officials with the Ministry of Health have reported 126 confirmed and 934 probable measles cases, according to a post on ProMED Mail. Most of the confirmed cases (121) are in Chihuahua. One of the Colorado measles case-patients is an infant who recently traveled to the Chihuahua area with family.
