Tip Sheet: Understanding the Spread and Prevention of Infectious Diseases Like Coronavirus
March 8, 2020 / by Michelle Thompson
Dr. Roess is a professor of Global Health and Epidemiology at George Mason University's College of Health and Human Services, Department of Global and Community Health. She is an epidemiologist with expertise in infectious diseases epidemiology, multi-disciplinary and multi-species field research and evaluating interventions to reduce the transmission and impact of infectious diseases. Dr. Roess served as the Science Director for the Pew Commission on Industrial Food Animal Production at Johns Hopkins, and was an Epidemic Intelligence Service (EIS) officer at the Centers for Disease Control and Prevention (CDC).
When disease outbreaks or other public health threats emerge, CDC EIS officers investigate, identify the cause, rapidly implement control measures, and collect evidence to recommend preventive actions.
Does tracking past outbreaks give us any insights into how coronavirus will behave?
Tracking past outbreaks gives us insights into when we might expect increases in cases and when we should implement interventions. It's important that we have unbiased systematically collected data when studying viruses in general so that we get a more robust understanding of how coronaviruses emerge and spread.
What makes it hard to tell how the virus will pan out as a global epidemic?
We are working on understanding emergence and transmission of viruses and there is still a lot that researchers have to learn. For example, we are still learning about how viruses change or mutate and what possible genetic or other markers make viruses spread and make them able to cause illness in humans.
Does the virus itself behave differently in terms of how it is spreading?
We are still learning about how this virus spreads and who is most likely to transmit the virus (asymptomatic versus symptomatic cases for example). We know from decades of experience that how we respond greatly impacts the spread of viruses. Improving hand hygiene behaviors significantly reduces the risk of respiratory infections at the individual level. Quarantining infected individuals and tracking/following their contacts over time is another effective intervention for halting the spread of the virus.
Is there any way to project what the situation will look like in three or six months?
It is hard to answer this question. We know from our experiences with MERS-CoV and SARS that these viruses tend to cause widespread epidemics early on when they are introduced into human populations and when they enter new geographical areas. Typically, over time their impact is reduced. It is unclear why that is and much more research is needed to understand this.
Is there any way to tell if the virus will be similar in other countries based on previous outbreaks?
What we know from MERS-CoV and SARS, and even Ebola, is that the quality of the health care system makes a big difference for how the virus spreads. For example, the U.S. had MERS-CoV cases that were quickly identified and hospitalized. There were no hospital associated outbreaks in the U.S. and no deaths. In contrast several countries in the Middle East experienced large-scale MERS-CoV outbreaks in hospital settings.
What is the timeline for a vaccine?
It is hard to know if a vaccine will be ready during this outbreak. Twelve months is an optimistic estimate quoted by many officials. It will depend on how the vaccines do in clinical trials and if we have a good vaccine then we have to consider manufacturing timetables. It will also depend on whether COVID-19 fades away as quickly as it emerged. If it does fade away quickly then history dictates that the resources diverted to come up with a vaccine will likely be diverted to other health issues.
What should the public should take seriously and what shouldn't they panic over?
The public should take it seriously that they have the power to reduce their individual risks by practicing good hand hygiene. We have evidence that supports that, proper hand hygiene together with avoiding touching your eyes, mouth, nose and food with dirty hands, individuals can significantly reduce your risk of respiratory infections. It seems simple but for most of us, it is not easy to remember to keep your hands clean and to keep them away from your face. Most people do not rigorously wash their hands for the recommended 20 seconds with soap and then dry them thoroughly. Maintaining a healthy diet and active life style with low stress is also hard but we have to try to do our best.
Is the virus dangerous on surfaces and is all this door-knob cleaning necessary?
Based on our current knowledge about this coronavirus, and from research about the other coronaviruses that cause SARS and MERS, It is important to remember that person-to-person spread is more likely because the virus is spread via respiratory droplets. Transmission of this coronavirus via contaminated surfaces has not been documented. Nevertheless, research shows that this novel coronavirus might remain viable for hours to days on several different types of surfaces and so it is important to clean high touch areas, like door knobs. These areas are most likely to have all kinds of pathogens.