Wisconsin DHS Health Alert #66: Nine Cases of Measles Confirmed in Wisconsin 

Bureau of Communicable Diseases

August 4, 2025 

Background

Measles is a highly contagious infectious disease that can be transmitted by direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes. On August 2, 2025, the Wisconsin Department of Health services issued a news release about confirmed measles cases in nine Wisconsin residents.  

At this time no additional exposed individuals or any public points of exposure have been identified. The risk to the community is low. 

DHS is working closely with CDC, the Oconto County Health Department, and other agencies to investigate cases of measles and prevent spread to the Wisconsin community. To accomplish this, it is important for health care facilities in Wisconsin to be vigilant for patients with suspected measles, take appropriate infection control precautions, and report any suspected cases to their local health department. 

For more details on health care facility preparedness and infection control precautions see the Measles Reporting and Infection and Prevention Control Measures message from March 27, 2025. 

For health care providers 

Only those health care providers who have documented immunity to measles should care for a suspected measles case. Documentation of immunity for staff should be collected in advance.  

Be prepared to care for a patient with suspect measles to help reduce the risk of transmission to others:

• Review policy and procedures regarding intake of a suspect measles case. Educate staff on infection prevention and control best practices, including the use of standard and airborne precautions.
• Contact your local and Tribal health department (LTHD) to facilitate testing. The LTHD will work with the DHS Immunization Program for approval of fee-exempt testing and to arrange logistics for transportation of the specimens to the Wisconsin State Laboratory of Hygiene (WSLH).
• Immediately report by telephone any suspected or confirmed case to the LTHD in which the patient resides.
• Ensure your facility is familiar with managing contacts of measles cases, including appropriate signage and triage processes.

For more details on managing measles cases, reporting, testing, and infection prevention and control see the Measles Reporting and Infection and Prevention Control Measures sent on March 27, 2025.

Recommendations for the public 

As of July 29, 2025, there have been a total of 1,333 confirmed cases of measles in the United States.  

The best way to prevent measles is to get vaccinated with the Measles, Mumps, Rubella (MMR) vaccine. Two doses of MMR vaccine are about 97% effective at preventing measles; one dose is about 93% effective. Prior to 1971, when MMR became widely available, millions of children in the United States were infected each year and 400-500 deaths occurred annually from measles.  

DHS recommends all children receive two doses of the MMR vaccine before age 4. Anyone born in or after 1957 who may have been exposed to measles should confirm their vaccination history and notify their health care provider or local health department if they are not certain that they have immunity. Those who were born before 1957 are considered immune to measles.   

Wisconsin residents can check their vaccination status in the Wisconsin Immunization Registry (WIR) or contact their health care provider or local health department. Most local health departments can provide MMR vaccine to uninsured children and adults based on vaccine availability and capacity. 

Thank you for your collaboration.

Sincerely,

Ryan Westergaard, MD, PhD, MPH
Chief Medical Officer and State Epidemiologist
Bureau of Communicable Diseases
Division of Public Health
Wisconsin Department of Health Services