Montgomery County has again changed its reporting methods for COVID-19.

In response to steadily increasing availability and use of rapid antigen testing, the county is now reporting positive antigen results in addition to PCR positive results, which it has been reporting since March, according to a Sept. 18 news release from the Montgomery County Public Health District.

Antigen testing is a newer type of COVID-19 testing that identifies an active infection, according to the health district. It detects proteins on the surface of the virus and generates faster results than a PCR test, which detects a virus’s genetic material.

"PCR tests are considered the 'gold standard' for testing, but on August 16, the [Centers for Disease Control and Prevention] issued interim guidance for antigen testing, including regulatory requirements, collection and handling of specimens, and evaluation of results," the news release stated. "Montgomery County Public Health District believes that over time, the addition of antigen positive results will provide a more accurate depiction of COVID-19’s impact on county residents."

Positive antigen testing results will now be counted and included in the county's total and active number of cases. The public will be able to differentiate antigen versus PCR cases by accessing the case-by-case list found at and clicking on “case updates." Case numbers that begin with “A" are antigen-positive cases.

MCPHD has been conducting cases investigations and contact tracing on PCR and antigen tests, according to the news release. All individuals who receive a positive result are directed to isolate for 10 days from the start of symptoms.

"MCPHD will continue to adjust reporting as the COVID-19 response evolves and new technologies and/or test types become available and are proven effective," the news release concluded.