Milwaukee’s COVID-19 Cases, Transmission Rate Dropping

The number of new cases of COVID-19 reported daily in Milwaukee County appear to be trending down after peaking in early July.

By the end of June, new cases in the county were beginning to sharply increase. And by early July, daily new cases of COVID-19 were peaking higher than the previous spike in May. The county’s suburbs became a hotspot for disease, with cases and transmission rates skyrocketing.

A weekly report compiled by epidemiologists from the Medical College of Wisconsin (MCW) shows new cases are going down, even in the suburbs. However, Darren Rausch, director of the Greenfield Health Department who’s been working with the MCW team, said, “what’s concerning to us in the suburban communities is our rates continue to be… higher than they have been throughout the outbreak.”

While the number of new cases does appear to be going down, there is a lag in testing data that puts the latest numbers a few days behind. And testing in the county is also going down. Meanwhile, the 14-day positive case rate (the percentage of tests that confirm new cases) remains stable, around eight percent. This past week’s positive case rate, 7.4 percent, was down from the week prior, 7.7 percent.

The dropping daily case numbers are a reflection of the county’s transmission rate (R-value) dropping below 1.0. This means for every confirmed case of COVID-19, that person, on average, is likely to give it to less than one other person. This means the county is suppressing the disease.

“The data today is promising,” Rausch said. “The data today indicates we’re moving in the right direction, but we can’t take our foot off the gas pedal, yet.”

In recent days, the county’s transmission rate has started inching back up, largely driven by rates in the suburbs. “The suburbs are certainly inching up closer to one than the city is,” Rausch said of the R-value.

Dr. Ben Weston, director of emergency medical services for Milwaukee County, said with three weeks of the mask order under the City of Milwaukee’s belt, it’s possible we are seeing positive outcomes already. Weston also said it’s important to persevere in social distancing measures and mask wearing to continue the positive gains made in recent weeks.

Among population subgroups, Hispanic residents still have a rate of COVID-19 about two times higher than other populations. However, starting in the early part of July, there has been a sharp increase among white residents.

Looking at a map of disease incidence, the south side of the City of Milwaukee and the southern suburbs currently are hotspots for COVID-19. In the last week, Oak Creek has some of the highest rates of the disease in the county. Greendale, Greenfield and Hales Corners are also showing up as hotspots with high rates of COVID-19.

Young people aged 18-39 continue to drive the disease’s spread, as they have the highest number of new cases and the highest transmission.

With school districts gear-up for reopening, a new report from the MCW team on COVID-19 among school-aged children aged 5-17 shows that disease trends among children “are very similar to what we see in the general population,” Rausch said.

While the number of new cases have been at a lower magnitude, there have been significant cases among school-age children, and cases have been growing since the beginning of July said Rausch.

“We’ve seen quite a rise in cases in the 10-19-year-old age group,” said Weston. “For confirmed cases of COVID-19 in the less than 18-year-old age group, we’re seeing for every 100 cases one to two of those individuals is getting hospitalized.”