Kansas health officials have confirmed 23 measles cases, marking an outbreak for the state as infections in at least 17 states have led to the most cases in the U.S. in a single year since 2019. The Kansas outbreak is spread across 6 southwest counties, the state's Department of Health and Environment said Wednesday.

The Kansas Department of Health and Environment, which reported one new measles case in the past week, now has a possible link to the Texas outbreak.

State health officials worry that declining vaccination rates have left many communities vulnerable nationwide.