The governor, who has a spotty track record of wearing face coverings, said he and the first lady "are both fine." He added he is not showing any symptoms.
Missouri is the second state to expand the health care program via ballot measure during the pandemic. Nearly a quarter-million people could get health insurance thanks to the measure.
Advocates for expansion say it would create jobs, protect hospitals from budget cuts, bring billions of federal taxpayer dollars back to the state, and bring health coverage to 230,000 more people.
Health and hospital officials in two states report that a Trump administration change to how pandemic data is collected has left them unable to access vital information.
Kanakuk Kamps shut down its K-2 program after 41 campers, staff and counselors tested positive. That number has since doubled, according to county health officials.
"Planned Parenthood has demonstrated that it provides safe and legal abortion care," a state commission ruled. It said state health regulators wrongly blocked the St. Louis clinic's renewal in 2019.
Missouri's attorney general alleges that China "engaged in misrepresentations, concealment, and retaliation to conceal the gravity and seriousness of the COVID-19 outbreak from the rest of the world."
The state has one remaining clinic in St. Louis, but Planned Parenthood officials say just three abortions were performed there in February, down from 174 in the same month a year ago.
The hearing on Thursday will use Missouri — where the last remaining clinic that provides abortion could close over a dispute with health regulators — as a case study.