As an infectious disease and clinical microbiology expert, Prof. Rodney E. Rohde of the Texas State University College of Health Professions receives daily calls from the media, government and university officials, public health and professional organizations and the public asking him about the emerging novel coronavirus outbreak. Here, he shares some of the most common questions and his responses.
Q: Considering that coronaviruses can technically refer to illnesses ranging from the common cold to something as serious as SARS, what makes this particular coronavirus strain significantly concerning?
Rodney Rohde: This is the name for a family of viruses that are mainly characterized by a positive-stranded RNA genome, and are bound in a membranous envelope. In recent history, this virus family has been extensively studied, as this virus family was responsible for the SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome) outbreaks in 2003 and 2012, respectively. Interestingly, coronaviruses are responsible for about a third of all common cold cases (rhinoviruses, adenoviruses, and others also cause the common cold). This virus, 2019-nCoV, is not similar to the more common coronaviruses, such as those that cause common colds. However, genetic analyses suggest this virus emerged from a virus related to SARS. There are ongoing investigations to learn more.
Novel outbreaks from any microbe should always be of public health concern. The risk from these outbreaks depends on characteristics of the virus, including whether and how well it spreads between people, the severity of resulting illness, and the medical or other measures available to control the impact of the virus (for example, vaccine or treatment medications).
The novel coronavirus is a serious public health threat. The fact that it has caused severe illness and sustained person-to-person spread in China is concerning, but it’s unclear how the situation in other parts of the world will unfold. In the US, authorities will continue to monitor the outbreak and incoming laboratory, healthcare, and public health data to produce the best possible plans and precautions.
The risk of acquiring infection is dependent on exposure. Outside the epidemic region, some people will have an increased risk of infection – for example, healthcare workers caring for 2019-nCoV patients and other close contacts. Likewise, the immunocompromised should be wary of exposure to any novel microbe. However, for most of the general public in the US who are unlikely to be exposed to this virus, the immediate health risk from 2019-nCoV is considered low.
Q: What do we currently know about the human-to-human transmission of this novel coronavirus? More specifically, once one person is infected, does the coronavirus appear to be significantly contagious in a human-to-human context?
RR: The modes of human-to-human transmission of the virus are still being determined, but given current evidence, it is most likely spread by the following, according to the CDC.
- Through the air by coughing and sneezing
- Close personal contact, such as touching or shaking hands
- Touching an object or surface with the virus on it, then touching your mouth, nose or eyes before washing your hands
- In rare cases, fecal contamination
With current data available and my professional experience, I do not believe this novel virus is any more contagious than the influenza virus. At this time, both appear to have similar transmission rates and case fatality rates (currently holding steady at about 2 percent). Of course, this could change, and it’s why we must monitor the outbreak closely and rely on “confirmed, and accurate” laboratory test results.
Lastly, it’s important to remember that until recently, all confirmatory laboratory testing (real-time RT-PCR molecular test) was occurring only at the CDC. This week, the US FDA granted emergency-use approval for state public health laboratories to starting testing for coronavirus using kits developed by the CDC. However, testing reagents and supplies could become limited due to rapid and expanding volume of testing.
Q: The number of coronavirus cases in China seems to have increased very quickly in a very short amount of time. In terms of human-to-human transmission of the coronavirus, how concerned should we be (if at all) about the fact that there are more confirmed cases in the US?
RR: As of Feb 6, 2020, there are 12 confirmed cases in the US, 76 pending cases, and 206 cases that were suspected but have tested negative. With any novel virus or other microbes, the rapid increase in detected cases is to be expected. The perfect storm of advanced diagnostic laboratory testing coupled with heightened awareness will certainly cause the daily rates and numbers to continue to climb. We should take typical precautions, much like we would for the influenza virus, such as hand hygiene, avoiding sick individuals, careful travel plans, and staying up to date on our vaccines, including the flu vaccine.
Globally, it is difficult to know the exact number of cases due to the uncertainty of asymptomatic cases or cases that are not being detected by testing. This map by the Centers for Disease Control and Prevention and this visualization by Johns Hopkins University Center for Systems Science and Engineering show the global spread of the virus.
Q: What are the main symptoms associated with this novel coronavirus?
RR: Symptoms will vary in severity. Current general symptoms include fever, difficulty breathing and cough. All or almost all diagnosed cases have pneumonia; some develop kidney failure or other organ dysfunction.
Q: How are the symptoms of this novel coronavirus different from those we associate with a typical common cold and seasonal flu?
RR: Both MERS and SARS (earlier coronaviruses) have been known to cause severe illness in people (~35 percent and ~10 percent, respectively). The complete clinical picture with regard to 2019-nCoV is still not fully clear. Reported illnesses have ranged from infected people with little to no symptoms to people being severely ill and dying. CDC believes at this time that symptoms of 2019-nCoV may appear in as few as 2 days or as long as 14 after exposure.
There are ongoing investigations to learn more. This is a rapidly evolving situation and information will be updated as it becomes available.
Q: In terms of screening/testing for the coronavirus and staying generally cognizant of the outbreak as it continues to develop, what do people need to know to protect themselves and avoid getting sick? Put another way: Do we need to do much else outside of our usual cold and flu prevention strategies (regular hand-washing, getting enough rest/fluids, staying home when sick, etc.) to stay safe during this outbreak?
RR: The data at this time tells us to treat this virus outbreak much like we would other respiratory agents like the common cold or flu. Certainly, US citizens should pay attention to reputable sources and heed the advice of the government and public health experts. The US Department of State has issued a level 4 “do not travel” advisory for China. Proper perspective is critical. There is no need to panic. We should all do our part in not becoming part of the problem as a “super-spreader” of inaccurate or unchecked information surrounding this virus outbreak.
Remember, each and every year, thousands of American citizens (and many more globally) deal with influenza, common cold, and other respiratory agents. In fact, in any given year, the typical estimate is 36,000 deaths a year in the United States alone, according to CDC reports. Thus, while we must pay attention to this outbreak and be prepared for any rapid changes, we must maintain perspective.