In a January 31 press conference, Nancy Messionnier, M.D., the director of the National Center for Immunization and Respiratory Diseases, said that “At this time, CDC does not have direct evidence that asymptomatic individuals are transmitting this virus.” Transmission during the incubation period didn’t seem to contribute to the spread of other serious human coronavirus infections like SARS, but with the new virus, we just don’t know yet. Only time will tell, and my infectious disease colleagues and I are anxiously monitoring the situation.
Clearly, experts are still working out a lot of these details. A lot remains to be known, including the actual impact the illness will ultimately have.
We don’t yet know how widespread or harmful the new coronavirus will be.
Before we go further, keep in mind that during an epidemic, the general public typically only hears about the most serious cases. It’s easy to overlook milder cases—involving people who report to their doctors and hospitals for treatment or simply stay home and recover—in favor of the more alarming stories. That’s not to say we shouldn’t care about the potential threat of serious illness and death in these situations, but that it’s also important to have the adequate context to avoid unnecessary fear.
With that said, the new coronavirus is currently spreading very quickly. At press time, over 24,554 global cases of the illness have been confirmed, according to the World Health Organization (WHO), with 24,363 of those taking place in China. Very much worth noting: Only around 13 percent of the confirmed new coronavirus cases in China have been deemed severe, according to the WHO.
As people who contracted the new coronavirus in China have traveled, the virus has spread from China to at least 27 other countries and territories. In the United States, we currently have 11 confirmed cases of infection in California, Arizona, Illinois, Massachusetts, and Washington. Most of these cases have been associated with people who had recently been in China, but on January 30, the CDC announced that the first U.S. case of person-to-person new coronavirus transmission had happened in Illinois. On February 2, another instance of U.S. person-to-person transmission was confirmed in California. Both cases of transmission happened when someone who had recently been to China spread the illness to someone they lived with in the U.S.
At press time, 492 people have died from complications of the illness (like pneumonia), with all but one of those deaths occurring in China (the only other death happened in the Philippines). Based on the number of confirmed cases, that’s a death rate of about 2 percent. (The fatality rate for the SARS outbreak in 2002 to 2003 was around 10 percent.) As the epidemic proceeds, many more people will become infected with outcomes we can’t predict right now. In a January Issues in Science and Technology article, Harvard epidemiologist Maimuna S. Majumder expounded on that idea, explaining that determining the true fatality rate of an infectious disease is difficult and changes over time as more populations are involved and mild cases are identified, which can lead to a lower death rate overall.
Based on what we know about new coronavirus so far, older individuals are most at risk of contracting and dying from it. A January study in The New England Journal of Medicine looked at demographic information of the first 425 people confirmed to have the disease in Wuhan, finding that nearly half of the infections were in people 60 and older. A recent The Lancet analysis of the demographic and health information of 41 people hospitalized with the infection found that a third were above the age of 60, and many had pre-existing conditions such as diabetes, hypertension, and heart disease. Being older and having these kinds of conditions both tend to put people at higher risk of all types of respiratory infections, so it’s not surprising that they’d be the hardest-hit from this coronavirus as well. Interestingly, there have been very few reported cases of children and teens with the infection. This illness seems to be striking (or at least causing noticeable symptoms in) primarily adults, at least from current data.
Right now, the flu is a bigger threat in the U.S. than the new coronavirus.
We don’t yet know the trajectory of the new coronavirus, which understandably invokes fear. But don’t let all the buzz make you forget about a different virus circulating in the United States right now with a much larger impact than the new coronavirus. It’s killed between 10,000 and 25,000 people in this country between just October 1 and January 25, according to the CDC, and has caused up to 26 million illnesses and 310,000 hospitalizations in that time as well. Schools in several states have closed due to high levels of this illness in their student bodies. We even have a vaccine available to help prevent it. Yes, I’m talking about the flu.