At least seven states may have botched their coronavirus testing tallies — potentially providing a distorted picture of how COVID-19 has spread, according to new reports.
Virginia, Texas, Georgia, and Vermont have been combining the results of two types of COVID-19 tests — swabs for the disease itself and antibody blood tests — in their total tallies, a serious concern as the nation begins to reopen, CNN reported Thursday.
In a separate report this week, the Atlantic reported said Florida, Maine, Pennsylvania had also been conflating the two because of testing guidelines from the Centers for Disease Control and Prevention.
Nose swab or saliva samples help determine if a patient currently has coronavirus, while antibody blood tests look for biological signals that a person has been exposed to the bug in the past.
Combining the two could paint an inaccurate picture of where and when the virus has spread in each state — and overstate the extent of the their testing, experts said.
“You only know how many cases you have if you do a lot of testing,” CNN senior medical correspondent Elizabeth Cohen said. “If you put the two tests together, you fool yourself into thinking you’ve done more testing than you have.”
Antibody tests are generally used on the broader population, rather than just those displaying symptoms, so they typically have a lower positive rate than nasal swabs — meaning a mix of the two “will drive down your positive rate in a very dramatic way,” Ashish Jha, a professor of global health at Harvard and the director of the Harvard Global Health Institute told the Atlantic.
Health officials in Texas, Virginia, and Vermont said in recent days that they clued into the problem and are working to fix it. Florida hopes to separate the the two tests in the next few week, according to the Atlantic. Georgia officials said its combined test numbers are in keeping with the CDC testing guidelines.
A new University of Minnesota report found that coronavirus testing nationwide was generally disorganized and not well coordinated between the states, CNN said in another report.
“It’s a mess out there,” Mike Osterholm, head of the school’s Center for Infectious Disease Research and Policy, told the outlet. “Testing is very, very important, but we’re not doing the right testing.”
“The data is really kind of screwed up,” he added. “It’s because the public health system is overwhelmed.”
As of Thursday, there have been more than 1.5 million COVID-19 cases in the US, with 93,000 people killed by the virus, according to Johns Hopkins University.