HOUSTON – One of the numbers watched closely by state health officials is the positivity rate. This the percentage of people testing positive for coronavirus over a 7-day period. Those numbers look to be heading in the right direction, but health experts warn it is not yet time to celebrate.
“I think it’s difficult to conclude that just because the positivity rate is dropping, the number of new infections is dropping,” said Dr. Stephen Spann, founding dean of the University of Houston’s new medical school.
According to data from the Department of State Health Services, Texas’ positivity rate peaked around mid-April, started to decline but then plateaued over the last several weeks. However, in the last few days, that rate has ticked down and is below 5%.
“Hopefully that trend will be sustained, but I think it’s hard to say,” said Spann.
His caution comes from the wider availability of tests. At first, only symptomatic people were tested.
“That meant the people being tested had a much higher probability of being infected just based on their symptoms,” said Spann.
Now, anyone can get tested regardless of symptoms or exposure to COVID-19.
“The issue is we are likely testing a less infected population now than we were early on just because of the availability of tests,” said Spann.
Dr. Peter Hotez, Dean for the National School of Tropical Medicine at the Baylor College of Medicine, also calls for a cautious approach to these numbers.
“If we’re going to have a problem here in Houston, Harris County or in Texas, we may not see it for a while,” said Hotez.
Hotez said increases in infection rates don’t happen overnight, especially since COVID-19 can take up to 14 days to present itself in a person.
“It takes a while for infected individuals to interact with one another and the big increase, the surge doesn’t come until much later,” said Hotez.
He said it could take until late summer or fall to determine Texas’ full infection rate. He’s calling on Texas to beef up the number of contact tracers and surveillance programs to quickly deal with potential flare-ups.