Viral and antibody tests for SARS-CoV-2 serve different purposes, but the Atlantic reports the US Centers for Disease Control and Prevention and several US states have been combining results from the tests. This, it adds, may be giving an inaccurate picture of the ongoing COVID-19 pandemic.
Viral tests determine whether someone has a current SARS-CoV-2 infection, while antibody tests gauge whether someone has ever been infected, and bundling those results together makes the data difficult to interpret, the Atlantic writes. In particular, Ashish Jha from the Harvard T.H. Chan School of Public Health tells it that as antibody tests are performed on the general population, rather than just people suspected of having COVID-19, they have a lower percent positive rate than viral tests do, and combining the test results "will drive down your positive rate in a very dramatic way."
A CDC spokesperson tells the Atlantic the agency hopes to separate the two data types in the coming weeks.
The Atlantic notes that it's not only the CDC that has mixed this data, but also states like Pennsylvania, Texas, and Georgia, among others. Some states have moved to also fix the issue.
"These results damage the public's ability to understand what is happening in any one state," the Atlantic writes. "On a national scale, they call the strength of America's response to the coronavirus into question."