Today on its online public health dashboard, the Missouri Department of Health and Senior Services (DHSS) began posting county-level data showing “probable” COVID-19 cases detected by antigen testing. Last fall, DHSS began reporting statewide numbers of reported negative and positive antigen tests.
DHSS will follow the guidance of the Council of State and Territorial Epidemiologists (CSTE) – the independent professional body that determines case definitions for the country. CSTE guidance subsequently affirmed by the U.S. Centers for Disease Control and Prevention (CDC) indicated that someone who has a positive antigen test for COVID-19 should be considered a probable case rather than confirmed.
Laboratory-based PCR tests continue to be the primary system and the gold standard for testing throughout the COVID-19 response as they provide a more definitive answer as to whether an individual has the virus in their body. Since last summer, antigen testing has significantly increased in availability and use. Like PCR testing, antigen testing is used to determine whether someone is actively infected with COVID-19, but these tests can generate results much quicker and do not require laboratory processing. Both probable and confirmed cases receive the same level of case investigation and follow-up.
In addition to probable cases for each county being displayed on the dashboard, county-level data showing tests and positivity rate are also available. The data is broken out by PCR/confirmed and antigen/probable.
“Antigen testing has been and continues to be a very effective tool as part of our mitigation strategy, and the use of this test has greatly increased in recent months,” said Dr. Randall Williams, director of DHSS. “Although the rate of community transmission continues to drop significantly throughout Missouri, having probable case information available for each county will help guide ongoing efforts to respond to COVID-19.”