Wisconsin health officials have detected measles virus in municipal wastewater in two of the three counties at the center of the state's southwestern outbreak. Samples collected from treatment facilities in Lafayette County and Iowa County during the week of August 24 tested positive for measles virus.
The case count rose with that finding. As of September 4, the outbreak in Grant, Iowa, and Lafayette counties stood at 136 laboratory-confirmed and six probable cases, for a three-county total of 142. Wisconsin has recorded 144 measles cases statewide so far in 2026, which leaves two cases outside the outbreak counties. The three-county figure is roughly triple the 48-case total MedicalDaily reported earlier in this outbreak.
