Wuhan Coronavirus: What We Know So Far
GLG’s VP & Content Team Lead for Healthcare, Michael Weissman, sat down with Dr. Stephen Ostroff on January 28, 2020 to discuss the Wuhan coronavirus. We discussed his insights into what we know so far about the virus, its current spread, and what we might be able to infer going forward. Dr. Ostroff was previously Deputy Director of the CDC’s National Center for Infectious Diseases during the SARS outbreak and, more recently, worked at the FDA for over five years, twice serving as Acting Commissioner.
GLG: Can you describe what we know about the symptoms of the Wuhan coronavirus, what populations of people are most susceptible, and the duration of the illness?
Dr. Ostroff: You would assume that everybody is susceptible to the virus. This seems to be a new infection in humans, which means there is no pre-existing immunity in any populations. Considering the patterns of illness to date and taking some clues from the other coronaviruses like SARS or Middle Eastern Respiratory Syndrome (MERS), it seems that the severity of the illness is directly proportional to age. Many of the deaths have occurred in older individuals.
As far as symptoms, the information so far suggests that the early manifestations of disease look somewhat like typical flu, but with some differences. The first symptoms are fever, fatigue, and difficulty breathing, rather than coughing and sneezing. In the early reports, no one has reported having a sore throat, which is usually a very common manifestation of influenza. This may be one way to distinguish people with the flu from this infection.
As time goes on, people have developed more shortness of breath and more of a cough. And by the time that they end up in the hospital, or in the intensive care unit, they have what looks like patchy pneumonia throughout their lungs. Reports from both inside and outside China have shown that mild cases of the illness have had a brief duration, lasting just a couple of days. More severe cases – where patients have ended up in the hospital – persist for 13 to 14 days between the onset of symptoms and death.
GLG: There have been suggestions that the virus could have originated from bats, snakes, or the Huanan Seafood Market in Wuhan. Why is it important for us to understand origination?
Dr. Ostroff: For the other severe coronaviruses, SARS and MERS, studies indicate that their origin is in bats, which we refer to as the natural “reservoir” of the virus. In the case of SARS, bats likely transmitted the virus to certain animals, such as civet cats, that were captured in the wild and brought into food markets. Bats are also presumed to be playing a role with the Wuhan virus. It is unknown what animal the bats may have transmitted the virus to, but it’s very unlikely that it’s snakes. These viruses tend to live in mammals and not in other types of animals. Snakes and fish are highly unlikely to be species to become infected with this virus. It is important to know the origin of the virus, because of the potential that it could reignite another problem down the line. Knowing the animal reservoir is essential.
GLG: Early reports suggest that the virus is transferable during the incubation period when people might not be showing symptoms yet. Does this seem to be the case? How does that impact the potential public health officials and decision makers?
Health authorities can usually screen individuals for symptoms when they enter the country. For example, when a plane lands from an area where the new coronavirus is present, you screen every passenger and if you find somebody who’s sick, then you pull them out and you put them in isolation until it’s been demonstrated that they don’t have the virus. For SARS, this was an effective way to help control the disease. But if people can be infectious when they don’t have symptoms – or when they have very mild symptoms – this strategy won’t work very well.
The question of whether there’s asymptomatic transmission is a very important one. Within the last couple of days, there’s been a couple of reports that raise the specter of asymptomatic transmission. The best evidence for asymptomatic transmission comes from a report that involves an individual who was attending a training seminar in Germany where one of the other attendees was a woman from China. This woman lived in Shanghai, not Wuhan, but her parents – who did live in Wuhan – had been visiting her in the week before she attended the seminar. In Germany, she was reported to be asymptomatic. She didn’t start developing symptoms until she was on the plane heading back to China. And yet somebody else who was attending the training seminar with her contracted the infection. If indeed she was asymptomatic while she was there, that would strongly suggest she as an adult was infectious and able to transmit before she had symptoms.
If people are transmitting the virus asymptomatically, taking all kinds of measures at the border to control the problem won’t work nearly as well. This is the case with flu and why this type of border screening was not recommended during the 2009 pandemic.
GLG: Is there anything that we can take away from looking back at SARS? What is the likely course of the Wuhan virus within China?
Dr. Ostroff: I can’t think of other recent emerging diseases that exploded as quickly as this one has. Over a period of five or six months, health officials identified 8,000 cases of SARS. The Wuhan virus has resulted in 4,000 or 4,500 confirmed cases in less than two weeks.
It will be important to monitor the number of cases outside of the outbreak area. How many of those cases are individuals with a connection to Wuhan? If we start seeing unlinked transmission chains in Shanghai or in Beijing or other parts of China, that will change things dramatically.
The government in China has taken dramatic steps, including putting this large area in quarantine or lockdown. Some think quarantine is a bad idea because it could accelerate transmission within Wuhan. Others think it’s a good idea. If you can effectively do the quarantine, it could minimize the potential or the likelihood that you will start seeing large transmission chains in other parts of China. But it is still too early to chart the true trajectory of the outbreak.
GLG: If we are still on the upslope in terms of the number of diagnosed cases, is it possible to make an accurate prediction of when we might see the potential peak?
Dr. Ostroff: Given the lack of immunity in the population and the virus’s lengthy incubation period, it makes predicting a peak a challenge. There are a couple of potential scenarios just to keep an eye on. For example, if the virus gets into, let’s say a country with a poor public health infrastructure that would have some challenges trying to easily control this, then that’s an entirely different sort of ballgame. All you need is one or two of these to slip through the system or get into a healthcare setting that doesn’t have very good infection control practices and you could start seeing transmission escalate.
GLG: What is your point of view on the potential spread in the U.S. and EU? We’ve seen a handful of cases confirmed so far in the U.S.. Do we expect to see a broader expansion of transmission in the U.S. and Europe?
Over a six-month period during SARS, there was a total of eight cases diagnosed in the United States. In one case, a husband transmitted his wife. The wife had not been in a SARS affected area. This was the only instance of SARS transmission within the United States.
In Toronto, approximately 200 cases of SARS occurred, virtually all of them in healthcare settings. These were healthcare workers and patients who were in the hospital or emergency department when people with SARS were present. It’s likely there was a small amount of transmission in the community in Toronto, but very little. They were able to control it because Canada – like the U.S. and most of Europe – has a very efficient public health system.
U.S. healthcare officials are closely monitoring contacts of the five individuals that have been diagnosed with the Wuhan virus in the United States. There are also approximately 100 others that are being evaluated for the virus. Some proportion of them have already been ruled out, but not all of them. They and their close contacts are all being very closely monitored and kept in isolation. And that’s probably the best way from preventing the virus from accelerating in North America and in much of Europe.
The wildcard is this asymptomatic issue, and how that might enter the equation. I think the likelihood that you’re going to start seeing sustained transmission similar to what has happened in China so far is relatively low, and I think will stay low until a little bit more information is available to reassure public health officials that they’re doing the right thing.
About Stephen Ostroff, MD:
Dr. Stephen Ostroff is currently employed at S Ostroff Consulting, since January 2019, where he holds the title of Public Health and Regulatory Consultant. He was previously Acting Administrator, Food and Drug Administration. Dr. Ostroff was the Deputy Director of the National Center for Infectious Diseases during the SARS outbreak of 2002-2003.
About Michael Weissman:
This article is adapted from the GLG Teleconference Wuhan Coronavirus. If you would like access to this teleconference or would like to speak with Dr. Ostroff, or any of our more than 700,000 experts, contact us.
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