By Brian Chasnoff and Joshua Fechter, Staff writers
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As Texas prepares to reopen under the threat of COVID-19, there finally might be reason to take heart — at least in San Antonio.
Bexar County could be over its peak of infections, officials say. Among the signs: a sustained decline in demand for tests.
While the county’s public and private health providers have the capacity to test about 1,600 people a day — and even as local officials pursue a goal of being able to test 3,000 a day — only 690 residents sought a test for the highly contagious coronavirus Tuesday. Earlier in the epidemic, more than 1,000 people a day sought tests.
On Thursday, Metro Health Director Dawn Emerick told the City Council that less than 1 percent of the county’s population of nearly 2 million is estimated to have COVID-19, a figure based on the number of positive cases: 1,374 on Thursday.
“It looks pretty good,” Emerick said in an interview. “We still haven’t had that classic 14-day consecutive decrease in cases yet. That’s the only (reason) I’m a little cautious to say, ‘Yes, there’s no disease.’ But the indicators clearly show that perhaps we are over the peak.”
Emerick added, “I don’t want to speculate, but what I can tell you is that the downward trend in testing is happening across the entire state.”
Even as Texas reported 50 deaths Thursday — the state’s highest daily toll yet — there were other heartening signs that Bexar County, at least, was past its peak.
Beyond numbers of new cases, another figure that’s critical to watch as the state reopens, experts say, is the test-positivity rate: the number of tests for the virus that come back positive. While not the same as the proportion of COVID-19 cases in a population, the rate can suggest the size of an epidemic.
On Thursday, the positivity rate in the county had fallen from more than 10 percent in previous weeks to 6.6 percent.
“That’s actually a pretty good indicator that there’s not that much disease out there,” said Cherise Rohr-Allegrini, an infectious disease epidemiologist serving on the COVID-19 Health Transition Team, a panel helping the city and county navigate a gradual reopening.
A high positivity rate is a warning that a community is not testing enough because doctors are testing only those with a high probability of infection. That was true here last month, when only hospitalized patients and health care workers were being tested for the virus.
The positivity rate for the United States is 17 percent, according to the COVID Tracking Project. Driving that number are staggering rates in places such as New Jersey, where nearly half of all people who get tested are positive.
In Texas, about 8.5 percent of tests for the virus are positive. Yet the state has tested only 1 percent of its population. Likewise, Bexar County had tested 1 percent of its population, or 21,672 people, as of Thursday.
Dr. Vince Fonseca, former chief epidemiologist for the state, said the lack of widespread testing is exactly why officials should keep a close eye on the positivity rate.
“About the only thing we have to go on is the test-positivity rate,” Fonseca said, adding that 6.6 percent still was too high.
“That’s clearly in the right direction,” he said. “Not good enough. We want it to go down, continually go down.”
Dr. Jimmy Perkins, former dean of the UT School of Public Health, noted some limitations to relying on the positivity rate to produce a picture of the epidemic.
For one, there’s the likelihood of false negatives — as high as 30 percent, he said.
“On the flip side of that, we’re not testing everyone who needs to be tested,” Perkins said. “I’m talking about people who just have symptoms. Getting a free test is not the easiest thing to do, especially if you’re not a person of means or you don’t have transportation.”
Despite the apparent drop in demand, Emerick said her department is trying to expand the county’s capacity to test and hire more people to trace contacts before an expected second wave of the disease hits in the fall.
“We know the wave is going to come,” Emerick told council. “We just don’t know how bad it’s going to be.”
Metro Health aims to boost its testing capacity to 3,000 tests a day by June 30. District 9 Councilman John Courage said that’s not fast enough, given that businesses already are gearing to reopen and the city isn’t testing residents to see if they’re asymptomatic carriers of the disease.
“Without the knowledge of what the general spread is of this, I’m afraid we’re walking around blindfolded,” Courage said.
Metro Health is planning to look for people who may be infected with the virus but aren’t showing symptoms and may be spreading the disease unwittingly, Emerick said. The plan is to pick 385 households at random and test them for the virus.
“We just don’t know the prevalence of asymptomatics in our community,” Emerick said.
The city also plans to expand access to testing with walk-up mobile testing sites in low-income parts of the city. The Texas Military Department is expected to add three more testing sites.
One idea is to retrofit a mobile unit used to test for sexually transmitted diseases to instead test people for the virus. The city also will expand testing for all nursing home residents and employees, the homeless and those with chronic kidney disease — whether they’re showing symptoms or not.
In general, local testing still is limited to residents who have symptoms of the virus, such as a cough, a fever or shortness of breath. One reason for imposing those limitations, Emerick said, is the continued scarcity of testing supplies.
“We can’t draw blood out of a turnip,” Emerick said. “And then when we do get the testing supplies, our first priority must be the symptomatic so we can control the outbreaks. We are not going to test the asymptomatic in a broad spectrum until we know the prevalence of that.”
To get a test, people who believe they have symptoms may call 311 and select option 8, or use Metro Health’s “self-screening” tool at sanantonio.gov. The COVID-19 test is free. The wait for results can take 24 hours to seven days.