The St. Louis region has made “important progress” in slowing the number of infections by staying home and taking precautions, said Dr. Alex Garza, incident commander for the St. Louis Metropolitan Pandemic Task Force.
“It is based on science and math,” said Garza, who is also chief medical officer for SSM Health. “With any contagious, dangerous virus like this coronavirus, you have to slow or stop its ability to spread from person to person. That is the reproduction factor.”
The goal is to keep the reproduction factor below 1, he said, which means each infected person is infecting less than one other person, on average.
“That is how you stop a virus,” he said.
The estimated reproductive factor takes into account both asymptomatic and symptomatic people. The task force includes the region’s largest healthcare systems: BJC HealthCare, Mercy, SSM Health and St. Luke’s Hospital. Garza has estimated that 70,000 people of the 2.8 million within the task force’s statistical area — which encompasses surrounding counties in Missouri and Illinois — will become infected with COVID-19. And 30 percent of those 70,000 will be asymptomatic cases.
When the region saw its first infection, the task force estimated that the reproduction factor was running above 5 — meaning that one infected person was spreading the virus to approximately five additional people, on average at that time.
“At that pace, we would be overwhelmed as a health system and we would lose many, many people to this virus,” Garza said.
When the stay-at-home orders went into place in the region in the third week of March, the task force leaders estimated the reproduction factor was around 2.
“That also would have been a very difficult situation for the entire community,” he said. “But, because of the work everyone in this region has been doing to stay home, wash hands and practice social distancing, right now, we believe we have brought the reproduction factor below 1. That is tremendous progress and allows us to keep this virus in check if it continues.”
If that reproduction factor spikes, Garza said we could easily see larger numbers of people becoming infected, getting sick and even dying.
“We want to do all we can to keep that reproduction rate down below 1 as we consider how to begin the stabilization and recovery process,” he said.
Testing will help manage the virus and keep the reproductive factor below one when restrictions begin to lift, he said.
“We will need the ability to conduct rapid and widespread testing, trace contacts, and isolate positive individuals,” Garza said. “That will be essential to keeping the reproductive factor below 1.0 and avoiding a second wave of infections.”
To keep the transmission low (<1.0), the region will need to be able to identify and isolate people who are infected and thus limit transmission.
“If we increase social activity or increase the interactions between people, we will invariably increase the probability of spread, unless we can identify and isolate those who are infected,” Garza said.
Currently the region is largely only doing “diagnostic testing,” and not the surveillance testing that needs to be done, he said.
St. Louis County Executive Sam Page announced on Friday, April 24, that the county will be hiring 100 people to do contact tracing, in addition to the 70 people who are already currently doing this work at the county’s health department. Page said increasing the contact-tracing workforce is an important part in lifting the stay-at-home orders.
“Contact tracing and testing are a big part of our response,” Page said Friday.
Garza has repeatedly said that the region needs to see a sustained decline in the number of hospitalizations and infections before we can consider relaxing stay-at-home orders.
“We have said that the peak is going to be coming this weekend,” said Garza. “We are still not on the downward side of the slope.”
On Sunday, April 26, inpatient hospitalizations are unchanged from Saturday — from 652 on April 25 to 652 on Sunday. The number of patients in the intensive care units has increased slightly — from 159 Saturday to 162 on Sunday. The number of patients on ventilators has decreased slightly — from 118 on Saturday to 115 on Sunday. Across the system hospitals, 20 COVID-19 patients were discharged yesterday, bringing the cumulative number of COVID-19 patients discharged to 1,102.
Dr. Garza gives daily briefings on the St. Louis Metropolitan Pandemic Task Force Facebook page at 3:30 p.m.
