DES MOINES — A Democratic state lawmaker said she has tested positive for COVID-19 and thinks she was infected with the virus at the Iowa Capitol, where Republicans have refused to mandate masks or require people to disclose positive cases.

The announcement by Rep. Amy Nielsen of North Liberty on Saturday night marked the first confirmed case among legislators, but there have been three other positive cases among people associated in the House since the legislative session began three weeks ago. One of those additional cases was announced by the House’s chief clerk Saturday, but the infected person wasn’t named.

Nielsen said she began feeling tired on Thursday and by Friday was feeling worse. She was tested on Saturday and the results were positive. She said she has lost her sense of taste.

Nielsen had decided with her family that she would not return home from Des Moines during the legislative session out of an abundance of caution and is relieved about that decision now. She has a husband and two children at home and another child away at college.

Nielsen, who said she wore a mask covering her nose and mouth but does not have eye covering, believes she contracted the virus at the Iowa Capitol, where Republican leaders have not required masks and do not require disclosure of positive cases. She said she’s gone nowhere else but to the building and briefly to a grocery store where everyone was masked.

House Speaker Pat Grassley was confronted several times by Democratic members last week during floor debate when he refused to put on a mask after requiring the members to talk with him at the speaker’s desk, referred to as the well during floor debate.

“I got called down to the well by speaker Grassley who refused to wear a mask. I tried to socially distance from him but you can only go so far,” she said.

Democratic Rep. Bruce Hunter refused to report to Grassley’s desk after a disagreement broke out with another House member during debate Thursday and Grassley ordered both members to his desk. Grassley wouldn’t put on his mask and Hunter refused, which prompted Grassley to tell him to continue with his remarks.

Other members frequently do not wear masks in the chamber, Nielsen said.

“I had a member and a guest standing right in front of my desk having an unmasked conversation and I had to ask them to please move,” she said. “The lack of a mask mandate and the lack of mandatory reporting is incredibly problematic.”

Grassley has said he cannot force members to wear masks and is unwilling to require members to leave if they don’t. House rules do require men to wear a tie and jacket when in session and blue jeans are prohibited.

“If they can tell me I can’t wear jeans on the floor they can tell me I have to wear a mask. It’s that simple,” Nielsen said.

She said wearing a mask is such a simple act of respect for colleagues and she expressed frustration that now she cannot do her work on behalf of her constituents because others refused to take precautions.

“I’m sure there’s got to be at least one person running around there asymptomatic that has it,” she said.

Grassley’s spokeswoman did not respond to a message on Saturday evening.

House Chief Clerk Meghan Nelson sent out an email Saturday alerting others working in the building that a positive test had been reported. Then later in the day a second notification was sent, which makes the fourth case identified on the House side of the Capitol since the session began Jan. 11.

The union representing state workers has filed a complaint with Iowa Occupational Safety and Health Administration claiming the majority leaders’ policies create an unsafe workplace. Inspectors were in the building Wednesday.