Measles Outbreak Escalates in Southwestern Wisconsin
A growing measles outbreak is causing concern in Wisconsin’s southwestern counties, underscoring the challenges posed by low vaccination rates. Health officials are mobilizing efforts to contain the virus, which has rapidly spread among unvaccinated populations.
According to the Wisconsin Department of Health Services, as of Friday, there have been 41 confirmed and 7 probable measles cases reported across Iowa, Lafayette, and Grant counties. The vast majority of those infected have not received vaccinations, with state data revealing that over half the cases involve children and teenagers, while 44 percent of cases are adults. More information is available on the state’s health website.
Efforts to halt the spread of this highly contagious disease are being hindered by vaccination hesitancy in certain communities. DHS spokesperson Jennifer Miller highlighted that the outbreak is primarily affecting areas with lower vaccination coverage. “Whenever there are pockets of lower immunization coverage — whether due to geographic location, health care access, or personal reasons — highly contagious viruses can spread quickly,” she stated.
The decline in childhood vaccination rates in Wisconsin mirrors national trends exacerbated by the COVID-19 pandemic. However, state data indicates that some southwestern communities have shown a decrease in the uptake of the measles, mumps, and rubella vaccine series even before the pandemic. For instance, only 60 percent of two-year-olds in Lafayette County had received at least one dose by 2025, with Grant County slightly higher at just under 64 percent.
In Iowa County, where the majority of recent measles cases have been detected, the vaccination rate is close to the state average at nearly 81 percent. However, this is still significantly below the 95 percent threshold needed to prevent outbreaks, as noted by the CDC.
Communities such as the Amish and Mennonites, known for their conservative lifestyle and selective use of technology, may be impacted by reduced vaccination rates. Wisconsin hosts the fourth-largest Amish population in the U.S., with over 3,000 Amish residents spread across Grant, Lafayette, and Iowa counties, according to Elizabethtown College data.
Mark Louden, a professor at the University of Wisconsin-Madison, noted the strong family ties between Plain communities in Wisconsin and Lancaster County, Pennsylvania, which is currently experiencing a major measles outbreak affecting over 300 people. While healthcare decisions in these communities are individualized, Louden described them as “vaccine cautious,” with families opting for certain vaccinations rather than following the standard schedule.
Louden also pointed out that skepticism towards vaccines is not solely rooted in cultural beliefs but is amplified by misinformation from non-Plain neighbors exploring “internet rabbit holes.” This sentiment echoes concerns raised by Jack Sauer, Lafayette County Board of Supervisors chair, who questioned the influence of national rhetoric on local vaccination rates.
Iowa County Health Officer Debbie Siegenthaler emphasized the importance of monitoring vaccination status, especially with children returning to school. Her department is actively working to identify potential exposures and ensure community access to vaccination and testing services.
Siegenthaler urged residents to verify their vaccination status through the Wisconsin Immunization Registry or healthcare providers, as the county prepares to host a community vaccination clinic at the Mineral Point Rescue Squad office on Monday, August 24, from 12 p.m. to 5 p.m.
