A new respiratory virus, coronavirus 2019-nCoV, appeared late last year in Wuhan, a large city in the central portion of China. It has spread rapidly and appeared to originate around live-animal markets in that city. This was an origin similar to the severe coronavirus SARS outbreak of 2002 and to the less severe MERS outbreak in 2015. SARS mortality was about a third. Fortunately, from very limited data so far the case fatality rate of this new coronavirus is under 5%, though that is hardly trivia. My Harvard Medical School classmate Dr. Edward Hoffer has an excellent and longer discussion of the outbreak.
What does the illness look like?
In practice, the description of the the new 2019-nCoV is similar to other substantial respiratory viruses. There should be actual fever and significant cough and difficulty breathing. Those are the hallmark of a lower respiratory tract virus, as opposed to the common cold (usually rhinovirus or adenovirus infections). But this is hardly a clear identification clinically. The CDC appropriately says these findings must be combined with a history of travel from Wuhan, China, in the previous 14 days, or the patient must have had close contact with a person under investigation for 2019-nCoV while that person was sick, or close contact with an ill laboratory-confirmed 2019-nCoV patient.
Given that we now have a scattering of cases in the US, there will certainly be more opportunities for exposure. In addition, given the rapid spread of the virus in China, the CDC now recommends, and we concur, that for now you should avoid any travel to mainland China.
Diagnosis not easy
There is yet no readily available lab test to distinguish this virus except at the CDC (Centers for Disease Control). If you become substantially ill and have had possible exposure in China or secondarily, please call to let us know. If symptoms are modest, staying home may be best for all. Keep to yourself, avoid coughing near others, and wash your hands regularly and carefully.
If we see you in the office, we will get you a mask at the door, and staff will wear masks. This is likely a droplet borne infection. But, as always, careful hand washing is critical to prevention of spread. The incubation period may be up to 14 days. We have no notice as yet of any antiviral therapy that is applicable.
Remember influenza A
Kindly remember that plain old influenza A produces about 70,000 deaths each year in our country. The likelihood of dying from flu is dramatically higher among people who are not vaccinated. We have tried to get all of you immunized against flu, but we have missed a few and some of you declined immunization. If we are fortunate, the case fatality for 2019-nCoV, for which there is no vaccine and no specific treatment, will remain low. We hope that aggressive public health measures will prevent it from becoming a widespread pandemic.
Dr. Kanner — can you write an update?
Update coming shortly.