Milwaukee COVID case burden, positivity up; delta variant dominant By FOX6 News Digital Team Published Milwaukee officials recommend masks indoors City of Milwaukee leaders are advising residents to mask up indoors even if they're vaccinated against the coronavirus. This, on the heels of new CDC guidance with the dominant presence of the delta variant causing an increase in positive COVID-19 cases. MILWAUKEE - The Milwaukee Health Department (MHD) on Friday, July 30 reported worsening COVID-19 case burden trends for the preceding week. According to MHD, the city saw 95.4 cases per 100,000 people, up from the previous week's 50.7 cases per 100,000. The gating criteria remains in the "substantial transmission" category.