On February 1, the United States declared the novel coronavirus outbreak, first identified in Wuhan, China, in late 2019, a public health emergency and began mandating a number of containment measures. These include travel advisories, airport screenings, and quarantine requirements that reflect both the rapid spread of the virus and the uncertainties about its evolution.
What is known is that the numbers of newly confirmed cases and deaths continue to climb rapidly. As of February 3, 2020, confirmed cases rose to more than 28,000 and deaths to more than 560, with most of these in China, according to the World Health Organization. With confirmed cases quickly spreading to at least 24 other countries, including 11 in the United States, healthcare officials are scrambling to learn more about how the virus is transmitted.
One unknown raising much alarm is whether asymptomatic transmission is possible. On January 30, the New England Journal of Medicine published a letter describing a cluster of infections in Germany that appeared to be transmitted from an asymptomatic carrier. A subsequent letter to the journal, however, disputed the accuracy of the letter, as reported on February 3 in Science. Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, told Science he still considers asymptomatic transmission probable, while others, such as the WHO, place its importance in context, saying that even if this is true, asymptomatic transmission would likely play a minor role in the overall spread of the virus.
The Science report also sheds light on another unknown about the virus: its severity. Virologist Christian Drosten of the Charite Univesity Hospital in Berlin was quoted as saying that the four cases of infection in Germany were all mild, suggesting that patients may have mild cold symptoms as they shed the virus. However, as reported on the same day in a CNBC report, Dr. Fauci stated that about 25% of the cases in China are considered very serious disease requiring various levels of intensive care.
To help healthcare providers navigate the situation, the CDC created an interim guidance on evaluating patients for suspected coronavirus. A simple flowchart on how to identify and assess the coronavirus can be downloaded here.
—Mary Beth Nierengarten