The CDC is maintaining updated criteria for the virus testing on its. Testing criteria are based both on clinical features and epidemiologic risk.
Individuals with less severe clinical features – those who have either fever or signs and symptoms of lower respiratory disease such as cough or shortness of breath, but who don’t require hospitalization – should be tested if they have high epidemiologic risk. “High risk” is defined by the CDC as any individual, including health care workers, who has had close contact with a person with confirmed COVID-19 within the past 2 weeks. For health care workers, testing can be considered even if they have relatively mild respiratory symptoms or have had contact with a person who is suspected, but not yet confirmed, to have coronavirus.
In its testing guidance, the CDC recognizes that defining close contact is difficult. General guidelines are that individuals are considered to have been in close contact with a person who has COVID-19 if they were within about six feet of the person for a prolonged period, or cared for or have spent a prolonged amount of time in the same room or house as a person with confirmed COVID-19.
Individuals who have both fever and signs or symptoms of lower respiratory illness who require hospitalization should be tested if they have a history of travel from any affected geographic area within 14 days of the onset of their symptoms. The CDC now defines “affected geographic area” as any country or region that has at least a CDCfor COVID-19, so that the testing criteria themselves don’t need to be updated when new geographic areas are included in these alerts. As of March 3, China, Iran, Italy, Japan, and South Korea all have Level 2 or 3 travel alerts.
The CDC now recommends that any patient who has severe acute lower respiratory illness that requires hospitalization and doesn’t have an alternative diagnosis should be tested, even without any identified source of exposure.
“Despite seeing these new cases, the risk to the American people is low,” said the CDC’s Dr. Redfield. In response to a question from the press about how fast the coronavirus will spread across the United States, Dr. Redfield said, “From the beginning we’ve anticipated seeing community cases pop up.” He added that as these cases arise, testing and public health strategies will focus on unearthing linkages and contacts to learn how the virus is spreading. “We’ll use the public health strategies that we can to limit that transmission,” he said.
*An earlier version of this article misattributed this quote.