Add South Dakota to the list of states reporting at least one case of measles this year (2025).

The state Department of Health says an adult in Meade County developed a measles infection after traveling internationally. The person visited several public locations, so community members may have been exposed to measles during the following times and locations:

Persons who were in those locations during that time are asked to self-monitor for measles symptoms for 21 days. The symptoms appear in two stages.

State Epidemiologist Dr. Joshua Clayton says measles is a highly contagious viral disease that spreads through the air from an infected person. He says individuals who lack immunity from vaccination or past infection have a high risk of contracting measles if they have contact with an infected person.

Clayton says the measles vaccine offers the best protection against infection and the risks that come with contracting measles. The first measles vaccine (MMR) is typically given at 12-15 months of age and the second dose is given at 4-6 years of age. He says the vaccine is highly effective at preventing measles, and two MMR doses usually produce lifelong immunity.

Clayton says if you are planning to travel internationally with children, MMR vaccines can be given to children starting at six months of age.

The following people are considered immune to measles:

Learn more about measles on the Department of Health website where information can be found in the form of fact sheets, frequently asked questions, and a webinar for healthcare providers.