Officials at the CDC and in multiple states have acknowledged that they combined the results of viral tests, which detect active cases of the virus essentially from the onset of infection, with antibody tests, which check for proteins that develop a week or more after infection and show whether a person has been exposed at some point in the past.

But in the ensuing weeks, antibody tests expanded and CDC officials realized they had a growing number of those mixing in with the viral results, the CDC’s Dr.

Pollock said officials are working to separate the data, but it is a labor-intensive process that could take another week or two.

Positive results from diagnostic tests were declining, according to published state data, but adding the antibody tests made the decline look steeper.

Delaware said it has “shifted focus” from reporting antibody tests and toward viral tests as they have become more available following nationwide shortages.

In Georgia, antibody tests were about 14% of the total, while in Mississippi, officials said they were around 3%.

The CDC told AP it knew of nine states that submitted viral and antibody test data together, but the list included some states that say they report those numbers separately, including Alabama and Kansas.

The CDC also gave the AP a list of 18 states it said had reported viral tests only, but that list included Pennsylvania, Virginia and Vermont, all of which have said they mixed the two kinds of tests together.

Maine officials say it’s not possible to release total test numbers more than once a week because the data must be collected from multiple outside labs doing the tests.

Kansas’s governor used to open media briefings with daily reports on positive test results and deaths but stopped doing that in early May when she began a push to reopen.

Nuzzo said COVID-19 has become politicized, creating pressure for officials to make their states’ data look good.