The US is experiencing its largest measles outbreak in 25 years, with over 1,000 cases reported nationwide.

An unvaccinated adult in central Iowa has tested positive for measles, marking the first confirmed case of the highly contagious respiratory virus in the state since 2019, the state Department of Health and Human Services said.

Iowa HHS wrote in a release Friday, May 23, that the case tested positive through the State Hygienic Laboratory. The state hasn't released the identity of the person who tested positive nor where they are from. No widespread public exposure is expected through the case, and an investigation has been completed.

Iowa is among 31 states that have confirmed measles cases involved in a growing nationwide outbreak that has totaled 1,024 cases, including three deaths because of the illness this year.

State Medical Director Robert Kruse said in the May 23 release that the best time to prevent measles is before an exposure occurs and the best tool to prevent measles is the measles, mumps, and rubella (MMR) vaccine.

"Getting vaccinated not only protects you but also protects people in your community who can't get vaccinated, like infants too young to begin the series and those who are immunosuppressed," Kruse said. "We ask Iowans to review their vaccination records and medical records to ensure they are protected and to reach out to their healthcare provider if they have questions."