March 03, 2020
The White House Coronavirus Task Force appeared at a press briefing March 2 to provide updates about testing strategies and public health coordination to address the current outbreak of the coronavirus COVID-19. Speaking at the briefing, led by Vice President Mike Pence, Centers for Disease Control and Prevention (CDC) director Robert Redfield, MD, said, "Working with our public health partners we continue to be able to identify new community cases and use our public health efforts to aggressively confirm, isolate, and do contact tracking." Calling state, local, tribal, and territorial public health departments "the backbone of the public health system in our country," Dr. Redfield noted that he expected many more confirmed COVID-19 cases to emerge.
At least some of the expected increase in confirmed cases of COVID-19 will occur because of expanded testing capacity, noted several of the task force members. On Feb. 29, the Food and Drug Administration issued a new policy to expedite the process for some laboratories to develop new diagnostic tests for SARS-CoV2, the virus that is causing the current outbreak of COVID-19.
Highly qualified laboratories, including both those run by public agencies and private labs, are now authorized to begin using their own validated test for the virus as long as they submit an Emergency Use Authorization (EUA) to the Food and Drug Administration within 15 days of notifying the agency of validation.
"To effectively respond to the COVID-19 outbreak, rapid detection of cases and contacts, appropriate clinical management and infection control, and implementation of community mitigation efforts are critical. This can best be achieved with wide availability of testing capabilities in health care settings, reference and commercial laboratories, and at the point of care," the agency wrote in a press announcement of the expedited test expansion.
On Feb. 4, the Secretary of the Department of Health & Human Services declared a coronavirus public health emergency. The FDA was then authorized to allow individual laboratories with validated coronavirus tests to begin testing samples immediately. The goal is a more rapid and expanded testing capacity in the United States.
"The global emergence of COVID-19 is concerning, and we appreciate the efforts of the FDA to help bring more testing capability to the U.S.," Nancy Messonnier, MD, director of the CDC's National Center for Immunization and Respiratory Diseases (NCIRD), said in the press release.
The new guidance that permits the immediate use of clinical tests after individual development and validation, said the FDA, only applies to labs already certified to perform high complexity testing under Clinical Laboratory Improvement Amendments. Many governmental, academic, and private laboratories fall into this category, however.
"Under this policy, we expect certain laboratories who develop validated tests for coronavirus would begin using them right away prior to FDA review," said Jeffrey Shuren, MD, JD, director of the FDA's Center for Devices and Radiological Health. "We believe this action will support laboratories across the country working on this urgent public health situation," he added in the press release.
"By the end of this week, close to a million tests will be available," FDA Commissioner Stephen M. Hahn, MD, said during the March 2 briefing.
The CDC is maintaining updated criteria for the virus testing on its website. 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 CDC Level 2 Travel Health Notice for 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 a severe acute lower respiratory illness that requires hospitalization and doesn't have an alternative diagnosis should be tested, even without an 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.