Virginia now lumps tests that diagnose COVID-19 together with tests that measure whether someone previously had the disease, and the state counts all tests toward the governor’s quest to reach 10,000 a day.
But not all tests are equal, or reliable, and Virginia acknowledges this and does not count a positive antibody test as a confirmed case.
Virginia on Monday reported 25,070 cases, an increase of 989 from Sunday. There have been 850 deaths, up 11 from Sunday’s report, linked to the coronavirus.
The Virginia Department of Health also reported that 167,758 tests have been given.
It is unclear how many were antibody tests. By counting those, Virginia boosts the overall number of tests and lowers the percentage of positive results. Both are key measures Gov. Ralph Northam has cited as ways to determine whether it is safe to move into Phase 1 of reopening Virginia.
Northam during his briefing Monday announced that 9,801 new tests were recorded during the past 24 hours, nearly hitting his mark.
Until the change, Virginia was counting only the diagnostic tests that are given when someone has symptoms of COVID-19. These tests are called RT-PCR, short for reverse transcription polymerise chain reaction, and they detect live viruses in samples collected on swabs inserted deep into the nose.
The other type of tests, serological, look for antibodies that are created when a body fights an infection. These blood tests are given at least a week or two after symptoms subside to determine if the coronavirus caused the illness.
“These tests are not as accurate as RT-PCR, the gold standard, so VDH is not counting someone as a case with that information alone,” the health department writes in its guidelines.
Somewhere along the line, a decision was made to count them in the gross total of tests.
Last week, Dr. Denise Toney, who directs the state’s testing lab, talked about the different tests during a news conference.
When asked if the daily test counts include antibody testing, Toney said, “At the current time, the information is being reported to the Virginia Department of Health, but I do not think they are being included in the total.”
The department has yet to clarify when it started to include serological tests.
“If they added that to their overall test results, that would be a very dubious approach, which would make me think they are just inflating their test numbers. It’s really mixing apples and oranges,” Jennifer Nuzzo, a senior scholar at the Johns Hopkins Center for Health Security, said during a phone interview last week.
Johns Hopkins has been tracking the coronavirus spread worldwide and in the states.
Virginia has been at the bottom of the site’s ranking for tests per capita among the states.
Northam’s chief of staff, Clark Mercer, said during the governor’s Monday briefing that Virginia is criticized for doing too few tests.
“I asked our team, and I had suspicions and continue to, about whether all states are reporting uniformly.” He said they checked with Johns Hopkins and Harvard and found they were not.
“It became clear other states were including serological testing,” Clark said. “So if you are going to compare us and be critical of the testing we are doing, and we aren’t comparing apples to apples, I think that’s grossly unfair.”
Dr. Norman Oliver, the state’s health commissioner, said Virginia looked to the Centers for Disease Control for guidance.
“There is no set guidance in that, so you’ll find variability among the states,” he said. “We choose to report it.”
Dr. Daniel Carey, the secretary of Health and Human Services, said, “The idea was to survey all the tests we could about this disease. In retrospect, we may have chosen a different path.”
Carey said the health department will look to untangle the tests to make it clearer how many of each type are in the mix.
This is not the first time the state’s methodology has changed without explanation, only to be clarified after reporters questioned it.
Virginia initially counted the number of people tested, then it changed to counting multiple tests given to one person. It now clarifies the gross number of tests from the unique number of people tested.
When tests results took many days or weeks to come in, and testing was still limited to only vulnerable populations, doctors began to report clinical diagnoses that were not confirmed by a lab.
The health department added these to the sum of cases without differentiating the types. Now it also separates the cases.
Health department spokeswoman Julie Grimes said antibody tests are received by the local health departments to follow up as resources permit.
Those with clinically compatible symptoms will be counted as probable cases, she said.
“As more is learned about the immune response to SARS-CoV02 infection and testing mechanisms are refined, the national approach to classification of positive results, and the VDH response to positive reports, may change,” she said.