The prevalence of COVID-19 among asymptomatic patients might be lower than some feared.

Dr. Donald Yealy, chair of the UPMC emergency medicine department, said no asymptomatic patients have tested positive for the virus in Western Pennsylvania since the hospital network last week began testing patients who come in for scheduled procedures, regardless of whether they have symptoms.

Yealy added that the program would likely expand — though did not give a specific timeline — to include patients who come in for any care. Eventually, he said, patients will be tested for COVID-19 antibodies.

Dr. Rachel Sackrowitz, UPMC ICU Service Center's chief medical officer, said only one patient out of about 500 tested across the hospital network's multi-state system tested positive for the virus under this program.

Yealy elaborated on the network's desire to add antibody testing, saying that many currently available tests are unreliable and “not much better than flipping a coin.” Expansion of testing will be done only when there is a proven reliable test, he said.

UPMC is developing its own antibody test, which Yealy believes will be ready in two to four weeks.

The testing of asymptomatic patients and health care workers is part of UPMC's plan to provide more elective, but essential, care to patients who may have been afraid to go to the hospital due to the pandemic. While the hospital system has been conducting elective care throughout the pandemic, Yealy said he is concerned that some patients may be delaying necessary care.

“It's safe” to get care, he added. “Do the right thing.”

Clinical trialUPMC continues to participate in REMAP-CAP, a clinical trial aimed at finding optimal treatment or treatments for patients with COVID-19.Sackrowitz said two drug treatments are mainly offered right now. Hydroxychloroquine — an antimalarial drug previously touted by the federal government, though the Food and Drug Administration has cautioned against its use outside a clinical setting — and steroids have been offered to patients enrolled in the international study that uses artificial intelligence to determine treatment options.Soon three more drug treatments will be offered, Sackrowitz said. Convalescent plasma, which is the blood of patients who have produced COVID-19 antibodies, as well as vitamin C and anticoagulants are in the pipeline.Remdesivir — an antiviral originally developed to fight the Ebola virus — is not yet in the works. Yealy said the two studies on remdesivir have shown little to no effect against the coronavirus.

A path forwardYealy said as many as 36,000 people in Allegheny County may have had the coronavirus but have had few to no symptoms.While that says the virus has spread more than has previously been known, he said, it also provides optimism in terms of the virus' lethality.Yealy came up with that number by estimating about 3 percent of that county's population were infected but recovered, basing that on antibody test results in the nation's hardest-hit regions. He earlier stated antibody tests may not be reliable.The case fatality rate — the proportion of people who died from a disease compared with the number of confirmed cases — ranges from 2 percent to 7 percent, Yealy said.But if the 36,000 number he quoted is accurate, the virus' true death toll in that county stands at about 0.25 percent. By comparison, seasonal influenza has a death rate of about 0.1 percent, according to estimates by the Centers for Disease Control and Prevention.Even with widespread testing, treatments in the pipeline and multiple proposed vaccinations for the illness, Sackrowitz said the coronavirus may be here to stay.“We expect that COVID-19 will be part of the disease burden, ... that it will be with us going forward, much like influenza,” she said.

The following data about the coronavirus pandemic are compiled daily from the Pennsylvania Department of Health’s website and regular releases from Butler Health System.Thursday’s COVID-19 statistics are as follows:Butler CountyConfirmed cases: 175Negative tests: 2,140Deaths: 6PennsylvaniaNew cases: 1,102Total cases: 44,366New deaths: 479Total deaths: 2,195Negative tests: 170,518Butler Memorial HospitalInpatients: 8Suspected: 1Confirmed: 7ICU: 0Total tests: 2,691Outdoor tests: 1,928Positive tests: 205Clarion HospitalInpatients: 2Suspected: 0Confirmed: 2ICU: 0Total tests: 586Outdoor tests: 473Positive tests: 22Surrounding CountiesAllegheny: 1,273 confirmed cases, 15,426 negative test results, and 86 deathsWestmoreland: 386 confirmed, 4,378 negative, and 25 deathsBeaver: 392 confirmed, 2,007 negative, and 65 deathsLawrence: 64 confirmed, 711 negative, and 6 deathsMercer: 65 confirmed, 707 negative, and 1 deathArmstrong: 50 confirmed, 647 negative, and 2 deathsClarion: 23 confirmed, 477 negative, and 1 deathVenango: 7 confirmed and 245 negative- The total cases includes confirmed and probable cases.- The total deaths and new deaths include only confirmed deaths, which is a person who tested positive for the virus before their death.