The city of Milwaukee has identified seven positive coronavirus cases linked to in-person voting on April 7, according to a city health official.

Six people who voted in person in Milwaukee tested positive, as did one poll worker, Health Commissioner Jeanette Kowalik told The Intercept. Tuesday marks the two-week incubation period since the election. The city's health department is still missing a significant amount of data from ongoing investigations into the spread of the virus following the election, she said, but they expect a more complete picture by Friday.

"Right now we have identified six cases that were tied to in-person voting. And one election worker was also positive," Kowalik said. "There are a lot of missing data through the investigations and contact tracing, so we're waiting for 70 percent of the fields to be populated."

The election-linked infections were identified through the Wisconsin Electronic Disease Surveillance System , an existing statewide program for reporting communicable diseases, and a version of which exists in every state. After the election, state officials added a field to the system, which is used by health officials and includes a voluntary questionnaire for people with illnesses, to ask whether respondents had either worked or voted in person on Election Day, where they worked or voted, when they developed symptoms, and if they had gotten positive test results. "That would be a flag for us, so that's how we found out that there's seven," Kowalik said.

The Wisconsin Department of Health Secretary Andrea Palm on Monday state health officials had not yet seen evidence that in-person voting contributed to an increase in coronavirus cases. DHS did not immediately respond to a request for comment.

Milwaukee opened only polling locations on Election Day, down from its usual 180. An estimated people voted in person in the city, meaning there was an average of 3,800 people at each location. The state Board of Elections has not yet released certified data on voter turnout, but initial results show that 1.55 million people voted, including close to 1.1 million absentee votes. Turnout was than in the 2016 primary, but similar to other primary years, around 34 percent of the electorate. Absentee ballots account for around of all votes, a drastic spike from 2016, expected given the ongoing pandemic.

In response to public pressure, Democratic Gov. Tony Evers made a late attempt to postpone the election and to make absentee ballots available to all voters. His efforts were first blocked by Republicans in the Wisconsin state legislature, and later by the state and U.S. supreme courts. The went to the U.S. Supreme Court, which eventually blocked the effort. The U.S. Supreme Court struck down an executive order Evers issued to postpone the election and also partially blocked an order from a lower court order extending the deadline for absentee ballots.

Other states that held elections in the middle of the pandemic have also documented cases of coronavirus related to in-person voting. In Illinois, which held its March 17 election against warnings from public health officials, a poll worker in Chicago died of Covid-19 on April 1. "Although the Board took every precaution possible by supplying poll workers with hand sanitizers, gloves, and instructions for wiping down the equipment, the fact remains that an individual who has now tested positive was likely present while you were voting," officials from the Chicago Board of Elections wrote in a .

In Florida, two poll workers at locations in Broward County tested for coronavirus following the state's March 17 primary. Another person who was working polls in Duval County also positive.

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