Dozens of people who tested positive for COVID-19 in Wisconsin had recently attended a "large gathering", according to a report.
Around 1500 people, including Trump supporters and those from right-wing groups, staged a mass protest against lockdown measures in the state's capital of Madison on April 24.
They gathered on the steps of the Capitol Building to push back against Democratic governor Tony Evers' stay-at-home order which was to expire on May 26 but has since been tossed out by the Wisconsin Supreme Court, news.com.au reports.
In the midwestern state, the Department of Health Services (DHS) interviews anyone who tests positive to COVID-19 to identify and notify their "at risk contacts".
DHS spokeswoman Jennifer Miller told American publication The Progressive they had gathered tracing data on a number of people who contracted the infectious disease.
"Possible exposures during protests haven't been specifically added to the database because we already ask about large gatherings," Ms Miller reportedly said.
"We were able to pull some limited data — out of 1986 cases with onset/diagnosis on or after April 26, there were 72 cases who reported attending a large gathering.
"No, it doesn't specifically state that the 72 were at a rally, but this is the data we have."
In an earlier email to the magazine, she said contact tracers ask patients if they attended mass gatherings but do not specifically inquire about protests.
"So there's really no data on who may have contracted COVID-19 at a protest," Ms Miller said.
GOVERNOR WARNS OF 'MASSIVE CONFUSION'
Wisconsin is one of several states where governors have run into increasing resistance from Republican legislators over coronavirus restrictions.
Democratic governors in Pennsylvania, Michigan and Louisiana have faced a mix of legislation and lawsuits aiming to curtail their power. In Kansas on Wednesday, Republicans resisted the Democratic governor's request to extend a disaster declaration.
A day after the state Supreme Court decision, Gov. Evers warned of "massive confusion".
The court's order threw communities into chaos, with some bars opening immediately while local leaders in other areas moved to keep strict restrictions in place to prevent further spread of the virus.
"This decision will hamper our ability to protect the health and safety of Wisconsinites and it risks increasing our cases and our deaths," DHS secretary-designee Andrea Palm said on Thursday.
"(The) ruling changes nothing about the science of this virus or the work we need to continue to do together to safely reopen Wisconsin."
If Wisconsin is to have a statewide plan, Evers will have to work with the same Republicans whose lawsuit resulted in Wednesday's Supreme Court ruling.
After a Thursday meeting with Evers, Republican Assembly Speaker Robin Vos said the two sides may not be able to reach agreement and that a statewide policy might not be needed.
"Apparently they believe that different rules are OK," Evers said of Republicans.
"I can't imagine another state that is in this predicament."
Vos downplayed the concern.
"We already know that local health departments have the ability to use their power, which is already there to deal with those situations if they feel it's unsafe," he said.
The Wisconsin ruling drew praise from President Donald Trump, who called it a "win" on Twitter on Thursday.
He added: "Its Democrat Governor was forced by the courts to let the State Open. The people want to get on with their lives. The place is bustling!"
Evers announced later Thursday that his administration had begun working toward a new administrative rule for managing the coronavirus crisis, a process he had warned could take weeks and might lead nowhere.
A notice made clear the new rule would mirror much of Evers' earlier recommendations.
As of Thursday, Wisconsin had more than 11,200 confirmed cases of COVID-19 and 434 deaths, according to the DHS.
– With AP