Health officials have lost track of how the coronavirus is spreading in Dane, Milwaukee and Kenosha counties, they announced Tuesday.

State health officials had announced Monday that community spread — which occurs when the origin of the virus can't be traced to travel history or previous contact with a confirmed case — was "likely" present in the state.

Tuesday brought confirmation, along with 25 new cases that brought the state's official total to 72. Later Tuesday, Milwaukee County announced 16 additional cases, and Fond du Lac and Sheboygan County announced one new case each.

Including those confirmed cases announced later Tuesday, there were 40 in Milwaukee County, 19 in Dane County, 12 in Fond du Lac County, four each in Kenosha and Waukesha counties, four in Sheboygan County, three in Winnebago County, and one each in Outagamie, Pierce, Racine and Wood counties. Only one patient, a Dane County resident, had recovered.

Department of Health Services chief medical officer Ryan Westergaard said local health departments will continue to investigate individual cases and perform contact tracing.

"Those are the ways we prevent onward spread," he said.

But community transmission brought more stringent statewide interventions that were announced Tuesday.

Gov. Tony Evers said the state will ban gatherings of 10 or more people, effective 5 p.m. Tuesday, to slow the spread, including closing bars and restaurants except for delivery and takeout.

Evers last week closed all public and private schools in the state until at least April 6. He said Tuesday that reopening was now "indefinite," because it wasn't known if April 6 was realistic.

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In other states where COVID-19 is believed to be circulating through community transmission, estimates of how many may actually have the virus have been stark: In Ohio, for example, top health officials estimated that more than 100,000 in the state could be sick. DHS officials declined to estimate that number for the state of Wisconsin Tuesday.

As the number of those with the virus grows, Westergaard said, not everyone with a case of COVID-19 will be counted because some cases will be mild. The state will estimate cases the same way it does for influenza.

There is an "urgent" need for people to stay home and practice social distancing now that community transmission has occurred, Tuesday's news release said.

Director of Public Health Madison & Dane County Janel Heinrich said in the release that orders to limit public gatherings to under 50 people may need to be amended to be "more restrictive" as the situation evolves.

Especially once community transmission has been identified, health experts have reiterated that it becomes a scenario of slowing the number of new cases, not preventing new cases entirely.

That's where the phrase "flattening the curve" has come into play — practicing social distancing, staying home when sick and following other mitigation strategies from federal, state and local health departments to ease the pressure on our health care systems to respond to the virus.

Contact Madeline Heim at 920-996-7266 or mheim@gannett.com. Follow her on Twitter at @madeline_heim.