In the U.S. at this time, the major risk presented by the current novel coronavirus (COVID-19) is not from the disease itself but from misinformation. Rumors, misinterpretations, and conspiracy theories are being transmitted at a rate far greater than that of the coronavirus itself. While the situation is evolving rapidly and things can change quickly, our understanding of the illness has also grown in a remarkably short period of time.


So, is this a pandemic?


In an NPR interview this week, WHO director-general Tedros Adhanom Ghebreyesus said the term is used to suggest that the spread of a new infection is out of control and doing significant damage worldwide. We are not quite there yet. COVID-19 transmission in China appears to have plateaued, and, while the virus has been detected in numerous other countries this week, several countries have also been successful in controlling the spread of COVID-19 within their borders. While the designation of a “pandemic” may step up the deployment of certain resources, it is at least as likely to promote panic and poor decision-making. The label won’t change anything about the way cases are tracked or people with the infection are treated.



Electron microscope image shows SARS-CoV-2—or 2019-nCoV, the virus that causes COVID-19—isolated from patient in U.S. Virus particles are shown emerging from surface of cells cultured in the lab. Spikes on outer edge of virus particles give coronaviruses their name, crown-like.
Credit: NIAID-RML

How worried should I be?



The WHO reports that as of February 28, there have been nearly 84,000 confirmed cases of COVID-19 worldwide and fewer than 3,000 deaths. In contrast, the CDC estimates that from October 1, 2019, through February 22, 2020, in the U.S. alone, there have been at least 32 million cases of influenza and 18,000 flu deaths.


While we have seen rapid transmission of COVID-19 in two months’ time, the speed of transmission (fueled primarily by the fact that this is a new virus in humans, to which we don’t have specific immunity) is not an indication of the severity of the disease. In fact, Dr. Margaret Harris of the WHO coronavirus response team notes that about 10-20 percent of people with COVID-19 need significant medical care, about 2% die, and 80% experience only mild to moderate illness.


The source of infection for the confirmed case of COVID-19 in California is not known. This suggests that the person was infected by someone in their community—someone not known to be infected, perhaps even an infected person who shows no signs of the disease. This is the way a brand-new infection travels: the first “ring” of infected people pick up the virus from a common source (in this case, possibly a seafood and live animal market in Wuhan); the infection travels to close contacts of some of these people; infections may be further spread within the community and through travel to places outside of the area; and eventually there may be enough of a hidden “reservoir” of infection in one geographic location to cause new cases of unknown origin.



Testing concerns in context.



There has been an uproar over the delayed testing of the recently infected person in California, and some have called CDC’s testing guidance “overly restrictive.” But when a new pathogen has been identified, a very specific case definition is the time-tested way to proceed. We can’t test “everyone”; this unnecessarily wastes clinical resources. There are always limited supplies of a newly designed test, and the simple limits of laboratory capacity restrict how many people can be tested. This occurrence, unfortunately, was an almost inevitable “glitch” as the situation in the U.S. transitioned from “travel-related only” cases to the start of community transmission.
Much has been made of estimates of the basic reproduction number, or R-zero (“R0”) of this coronavirus, and whether it suggests that spread can be more rapid than more familiar viruses. It’s critical to keep in mind that the R0 number refers to the rapidity of transmission when nothing is being done to contain its spread. This kind of “in vitro” number has relevance to researchers and epidemiologists but minimal practical or clinical relevance.



Why are we only hearing about “estimated” death rates from COVID-19?



We can’t know the true death rate of a pathogen until we know more about the numbers of people with mild or asymptomatic cases. As usual with a new virus, the first cases to be identified are those of people who are sick enough to seek medical attention. It is virtually certain that, as with many other pathogens, some of the people infected will not feel sick, or may have only mild symptoms.


Serological testing of a large number of people in a community is necessary in order to pick up asymptomatic cases and arrive at a “denominator” number of actual people infected (though possibly not sick). (A serological test for antibodies is not the same as the (RT)-PCR test now being used to diagnose COVID-19 disease.) Usually, once this more accurate count of infections can be made, the denominator increases (often significantly) and the death rate goes down—not up. In other words, we may be seeing the worst of this infection now, among already identified cases, and we are likely to see the death rate drop in the future. A serologic test for this coronavirus appears to be on the horizon, and may soon be available to help with tracking and controlling the spread of this virus.



What should I do to protect my patients and myself?



The basics matter. The key to controlling the spread of a new pathogen rests more with individual actions than with government pronouncements. And we already know what to do. Don’t let the “simplicity” of these recommendations obscure the fact that they should be our focus during this unfolding epidemic. Just get really good at your practice!


  • People with fever and cough who think they may have coronavirus should call their local public health hotline for instructions. Alternately, call your own provider or local hospital BEFORE GOING THERE.
  • Clean your hands often with soap and water (20 seconds or more) or an alcohol-based hand sanitizer. Train yourself to keep your hands away from your face and hair unless you have just cleaned your hands.
  • The CDC does NOT recommend wearing masks, except during the care of a person with a respiratory infection either in a health care facility or at home. The new coronavirus is thought to be spread primarily by droplets, but if COVID-19 is suspected in a hospital patient, the routine use of airborne isolation precautions and N95 masks are recommended until we know more about the new virus.
  • Disinfect surfaces regularly. Coronaviruses are susceptible to standard hospital-type disinfectants; just be sure to “wipe with intention”—firmly and thoroughly.

It’s a good idea to check regularly with the CDC, who have regularly updated information and guidance. Here’s their COVID-19 page for health care professionals:  https://www.cdc.gov/coronavirus/2019-ncov/hcp/index.html