Wisconsin DHS Health Alert #71: Two Locally-Acquired Measles Cases Identified in Southwest Wisconsin
Bureau of Communicable Diseases
August 11, 2026
Key points
- Cases of measles have been confirmed in a resident of Lafayette County and in a resident of Iowa County. Both cases have been confirmed through laboratory testing. The Wisconsin Department of Health Services (DHS) is working with Lafayette County Health Department and Iowa County Health Department to investigate the cases and notify anyone who may have been exposed.
- The individuals were likely exposed to measles in Wisconsin, indicating there may be additional measles cases in the community that have not yet been identified.
- Vaccination should be recommended to prevent further cases of measles.
- Health care providers in Wisconsin should review protocols for managing patients who present with measles-like symptoms. All suspected measles cases should be reported to the local health department to coordinate testing and investigation.
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 11, 2026, DHS issued a news release confirming two measles cases in Wisconsin residents.
At this time, there have not been any public exposure locations identified. However, the investigation is ongoing and any public exposure locations identified will be listed on the DHS Outbreaks and Investigations webpage.
DHS is working closely with CDC (Centers for Disease Control and Prevention), Lafayette County Health Department, and Iowa County Health Department to investigate cases of measles and prevent further spread. 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.
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Immediately report by telephone any suspected or confirmed case to the LTHD in which the patient resides. PCR and serology samples for suspect cases should be sent to WSLH for fee-exempt testing.
- 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 30, 2026, CDC has confirmed 2,371 cases of measles cases occurring in the United States in 2026.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
Resources
For information on measles testing and case reporting, review the Measles Reporting and Infection Prevention and Control Recommendations March 27, 2025.
For details on measles testing see DPH Communicable Diseases Memo 2026-05 Measles Testing and Public Health Notification: Guidance for Wisconsin Clinicians (PDF)
For detailed guidance regarding measles case investigation and reporting see:
Questions regarding this health alert may be directed to the Wisconsin Immunization Program by email at DHSImmProgram@dhs.wisconsin.gov or by phone Monday through Friday from 8 a.m.–4 p.m. at 608-267-9959 or after hours at 800-943-0003 (option 4).
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