CDC's First Response to the Novel Coronavirus, December 2019–February 2020

On December 31, 2019, health officials in China reported a cluster of acute respiratory illness among people linked to the Huanan seafood and animal market in Wuhan, Hubei Province. On January 7, 2020, they confirmed that a new coronavirus, then called 2019-nCoV, was the cause. This CDC report, posted on February 5, 2020, is a snapshot of the U.S. response through February 4, written when only 11 Americans were known to be infected.

Where things stood on February 4, 2020

Nine of the first 11 U.S. patients had been exposed in Wuhan. The first U.S. case was reported on January 21.

What was known about the virus

Like the coronaviruses behind MERS and SARS, the new virus appeared to have come from animals, though its exact origin was undetermined. It spread from person to person, but how easily was unclear; MERS and SARS spread mainly by respiratory droplets. Confirmed patients had fever, cough and shortness of breath. Based on MERS and SARS, CDC believed symptoms appeared 2 to 14 days after infection. Older adults and people with underlying conditions or weak immune systems might be at higher risk of severe illness.

The response

• Organizing. CDC set up an incident management structure on January 7 and activated its Emergency Operations Center on January 21, sending teams to states with cases to trace contacts and study the disease.
• Travel notices. On January 27, CDC advised against all nonessential travel to mainland China (a Level 3 notice).
• Airport screening. From January 17, travelers from Wuhan were screened at Los Angeles, New York (JFK) and San Francisco airports, later also Atlanta and Chicago — together about 85 percent of air travelers from Wuhan. By February 1, 3,099 people on 437 flights had been screened; five with symptoms were referred for care, and one tested positive. All received a health notice advising them to watch for symptoms for 14 days.
• Emergencies declared. On January 30 the World Health Organization declared a Public Health Emergency of International Concern; on January 31 the U.S. Health and Human Services Secretary declared a U.S. public health emergency, and a presidential proclamation limited entry of travelers from mainland China to U.S. citizens, permanent residents and their families. Screening moved to 11 airports receiving all air travelers from China.
• Testing. China posted the virus's genome on January 10. Within a week, CDC had a real-time RT-PCR test, whose protocol it published on January 24. An FDA Emergency Use Authorization allowed the test beyond CDC's own labs, in qualified labs across the country, and CDC worked to share it at home and abroad. CDC posted the genome of the first U.S. cases to GenBank and was growing the virus for research.

Guidance for clinicians

There was no vaccine or specific treatment; care was supportive. Clinicians were told to take detailed travel histories and to evaluate as possible cases people with fever or lower respiratory symptoms who had close contact with a confirmed patient, had traveled from Hubei, or needed hospitalization after travel from mainland China, all within 14 days. Suspected patients were to wear a surgical mask, be separated from others by at least 6 feet, and be seen in a private room — ideally an airborne infection isolation room — by staff using standard, contact and airborne precautions and eye protection. Clinicians were to notify infection control staff and the local health department at once; if testing was advised, both upper and lower respiratory specimens were to be collected.

How it looked then

For the general public, the immediate risk was judged low. But with an estimated 14,000 travelers arriving from mainland China every day, CDC expected more U.S. cases and chains of transmission, and acknowledged that its measures might not prevent the virus from eventually spreading widely. Eight of the first 11 cases had been found by clinicians working with public health to test people at risk. Because the new illness resembled influenza, and arrived in flu season, CDC urged everyone 6 months and older to get a flu shot, to reduce confusion between the two.

Sources

Based on "Initial Public Health Response and Interim Clinical Guidance for the 2019 Novel Coronavirus Outbreak — United States, December 31, 2019–February 4, 2020," by Anita Patel, Daniel B. Jernigan and the 2019-nCoV CDC Response Team, Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention; a work of the United States government in the public domain. An erratum to the report has been published.