Over the last few months, the FDA has given Emergency Use Autorizations to 4 different antigen tests. Antigen tests aren’t as accurate as the Polymerase Chain Reaction tests but provide nearly immediate results which provides timely and actionable information. This feature makes antigen tests a very valuable tool in many settings like testing staff in assisted living and skilled nursing facilities. 

Until last week, Arizona’s public health system counted a person with a positive antigen test as a case only if they also had a known exposure to a person with COVID-19 or have symptoms of COVID-19 like shortness of breath, cough, or sore throat.

Last week, AZ’s public health system changed how they count cases by including anyone with a positive antigen test as a probable case, consistent with the recently updated national case definition for COVID-19 from the Council of State and Territorial Epidemiologists. A good decision.