The Measles cases in the USA are increasing rapidly, with 15 confirmed cases and six probable cases now linked to a measles outbreak in Wisconsin. According to state health officials, the latest Wisconsin measles cases are concentrated in Iowa and Lafayette County residents. Testing at the Wisconsin State Laboratory of Hygiene confirmed the initial cases, and health officials subsequently identified additional infections.
DHS is investigating the measles outbreak in Wisconsin and identifying people who may have been exposed. Officials have not identified public exposure locations connected to the Wisconsin measles cases at this time.
The latest measles cases in Southwest Wisconsin are unrelated to two earlier Wisconsin cases reported in Dane and Waukesha counties. Those infections were associated with international travel.
The Symptoms of Measles Infection
Measles is one of the most contagious viral diseases. It spreads through the air when an infected person coughs or sneezes and can remain infectious in the air for an extended period.
Symptoms of Measles generally include:
- High fever
- Cough
- Runny nose
- Red or watery eyes
- A widespread skin rash
Wisconsin health officials say symptoms typically appear about 10 to 21 days after exposure. The disease can also lead to serious complications. DHS has reported that about one in four people with measles require hospitalization.
MMR Vaccine Remains the Best Protection Against Measles
The most effective way to prevent infection and limit further transmission is the measles vaccination. Two doses of the MMR vaccine (measles, mumps and rubella) provide about 97% protection against measles, according to state health officials.
Residents should check their vaccination records and speak with a healthcare professional if they are unsure whether they have received the recommended doses of MMR vaccine.
Wisconsin Cases Add to 2026 U.S. Measles Outbreak
The measles outbreak in Wisconsin comes as measles activity remains elevated across the United States. Wisconsin Public Radio reported that more than 2,400 measles cases had been confirmed nationally by early August, making 2026 a particularly significant year for measles transmission in the U.S.
The Wisconsin situation also follows measles activity in other states. Delaware has recently confirmed its first measles case in more than a decade in a Kent County resident and began contact tracing after identifying an unvaccinated adult with the infection.
Next Step In Measles Outbreak in Wisconsin
Wisconsin health officials will continue testing, investigating potential exposures, and monitoring for additional infections. Because measles spreads easily, identifying cases quickly will help interrupt the measles outbreak in Wisconsin.
Residents who develop measles symptoms after a possible exposure should contact a healthcare provider before visiting a clinic or hospital. Calling ahead allows healthcare teams to take infection-control precautions and protect other patients and staff.
The Wisconsin DHS measles dashboard is updated weekly, but officials note that case counts remain provisional and can change as investigations continue.
