With more than one-fifth of Missouri’s COVID-19 cases tallied in the past week, Columbia health officials are urging people to wear masks, follow social distancing guidelines and remain in quarantine for at least 14 days after possible exposure.
Elsewhere in the state, local leaders are pulling back on steps to reopen businesses and other activities, with St. Louis limiting gatherings to 50 people or fewer beginning Friday.
In Boone County, where more than half of cases involve people under 30, the Columbia-Boone County Department of Health and Human Services reported Monday that positive rates for tests are down from their peak but remain high.
From July 8 through Sunday, 93 of 454 new cases were among people 19 and younger, and 106 among people 30 to 44, a prime age for parents of the younger group.
"Yes, we are definitely seeing spread among family units, or more generally, household contacts," wrote the health department’s assistant director, Scott Clardy.
Statewide over the past two weeks, the share of cases among people 20 to 29 years old has increased by about 800 more than if their share had remained unchanged.
Contact tracing is showing that eight or nine people are being infected by each case in that age group, state Health Director Randall Williams said, and in many instances, they were not wearing masks when exposed.
In Boone County, health officials are reporting that people know who infected them when contact tracers call, Williams said.
"The temptation to go out in the summer and congregate is great," Williams said during a briefing with Gov. Mike Parson. "We really, really need them to follow those basic public health measures and that is not happening."
In Boone County, for the week ending Thursday, 7.2 percent of people tested were positive for the coronavirus that causes COVID-19. That is up from 6.2 percent the previous week but down from 16 percent during the first week of July.
A rate above 5 percent is concerning, the department stated in a news release.
Since July 10, Columbia has required people to wear face masks in public and private indoor spaces and the decline in the positive rate could be partially a result of the mask mandate, the release stated.
But masks are not a substitute for social distancing.
"We are hopeful that more people wearing masks will help lower our rates of infection, but it’s important to continue all other efforts to remain COVID aware, including social distancing to the greatest extent possible, regularly washing your hands, and staying home if you are sick," said local health department Director Stephanie Browning.
When someone in a household tests positive, Clardy wrote, they should keep to one room of the house, not share the bathroom. Everyone else should quarantine for 14 days and get tested.
"We recommend close contacts be tested at 7 to 9 days after their last contact with the confirmed case, but even if they test negative, they need to stay in quarantine for the entire 14 day period as they could become infectious at any time during those 14 days," Clardy wrote.
Boone County is currently under a health order, in effect until Aug. 10, prohibiting restaurants and bars from offering standing counter or buffet service and limiting gatherings to no more than 100 people.
Personal care facilities like salons may only operate at 50 percent capacity or a total of 50 people, whichever is fewer.
During the Monday briefing, Parson urged counties to get federal COVID-19 funds to local health departments to increase contact tracing. The state has moved more than $500 million to counties, but only 17 of 81 local health departments surveyed have received cash to support their prevention efforts, he said.
The Boone County Commission is working out the details of providing $1.8 million to the department, with $810,000 for testing uninsured people and hiring 40 temporary staff, Clardy said.
Missouri reported 1,123 new infections on Monday, bringing the seven-day total to 9,426 out of 43,050 reported since March. St. Louis County, which reported 520 new cases Sunday and 157 more on Monday, is issuing new orders limiting crowd sizes, ordering bars to close early and urging parents to teach their children virtually if possible when the school year starts.
St. Louis County Executive Dr. Sam Page said the new restrictions would take effect at 5 p.m. Friday.
St. Louis County has 11,152 cases by the state’s tally, more than a quarter of the state's total. The number of infections is thought to be far higher because many people have not been tested, and studies suggest people can be infected with the virus without feeling sick.
"This is serious," Page said. "This will overwhelm our community. This will overwhelm our hospitals. The decisions we are making today will not bend the curb for at least three weeks."
The new restrictions include limiting gatherings to no more than 50 people, rolling back the number of people allowed in businesses, closing bars starting at 10 p.m. and working with business to ensure they are complying with the rules.
"If businesses are not playing by the rules, they should not be open," Page said.
Page said people waiting for test results must quarantine and that spaces will be found for teachers to quarantine if needed. There also will be a push to ensure health care providers are reporting their testing promptly.
Page also urged parents to strongly consider avoiding in-person schooling for their children unless absolutely necessary.
"Please know that we are trying to take as many steps as we can to flatten the curve and provide a safe option for our parents later this year to have an in-school in classroom setting for their students if they chose that option," he said.
"But even with these steps, even with that knowledge, it is my recommendation as a parent that parents who can choose a virtual option if it is available. And I know that that virtual options will be difficult for many."
But he also acknowledged virtual learning isn’t a good fit for many families.
"Some parents who have child care needs and some parents who have kids with special needs," he said. "They need that support structure and that predictability in order for their kids to be able to learn."
Heather Hollingsworth of the Associated Press contributed to this story.