Novel coronavirus outbreak - experts
respond13 May 2013
A new coronavirus -- the same type of virus responsible for the 2003 outbreak of Severe Acute Respiratory Syndrome or SARS -- has been identified as the cause of an increasing number of illnesses and deaths in several countries.
The World Health Organisation's most recent media statement on the virus is available here.
A second case of the novel coronavirus in France was announced yesterday and confirmed as the result of patient-to-patient transmission within a French hospital. The news has prompted some to speculate whether coronavirus will be behind next global pandemic.
The Science Media Centre has rounded up the following reactions from experts in virology and infectious disease.
Dr Sue Huang, Director - WHO National Influenza Centre, National Centre for Biosecurity and Infectious Disease, Institute of Environmental Science and Research (ESR), comments:
What is coronavirus, where is it coming from and why is it concerning?
"Coronavirus represents a group of viruses. Some of them cause mild symptoms such as common colds. However, some coronaviruses -- such as the SARS virus which caused nearly 1000 deaths in 2003 with thousands of people infected -- are much more severe.
"This new coronavirus is NOT the SARS virus and they are different from each other. However, the fact that it is related to the SARS virus and that it can cause severe pneumonia is raising concerns.
"We do not know where this new coronavirus has come from. We know its sequence is close to the bat coronavirus sequence, however, this new coronavirus has not been detected from any animal species including bat. This is our knowledge gap at the moment."
What do the new cases tell us? What is the potential for a pandemic?
"As of 8 May 2013, a total of 30 laboratory-confirmed human cases of novel coronavirus, including 18 deaths, have been reported to the WHO since March 2012. However, the most recent 13 new cases including 7 deaths have been reported since 14 April 2013 from Saudi Arabia. These cases presented with severe acute respiratory disease requiring hospitalizations and eventually needed mechanical ventilation. There are small clusters with limited person to person transmission. However, there is no evidence that this virus has the capacity to cause sustained person-to-person transmission in community. Thus, this new virus has not reached a point to cause a pandemic."
What are the next steps?
"Although the virus has not reached the point of causing a pandemic, it does have potential to cause pandemic if it acquires the ability to transmit efficiently in the human population. Therefore, it is very important for the global community, including New Zealand, to increase the level of surveillance for this new infection.
"In addition, the global scientific community needs to fill in knowledge gaps about this new virus: Where does the virus live? Is it from animals? If so, which animal species? How do people get infected? How widespread is this virus in the Middle East? To what extent have people in this region been exposed to the virus?"
Professor Michael Baker, Dept of Public Health, University of Otago, Wellington, comments:
"The World Health Organisation is right to take the threat of this novel coronavirus seriously.
"The arrival of SARS in 2003 reminded us that entirely new human infections can emerge without warning and develop into global epidemics that may be difficult to control. These new human pathogens generally come from animal sources (so are zoonotic) and threaten human health when they develop the ability for person-to-person transmission, usually via the respiratory tract (mainly through coughing which generates droplets, airborne particles and contaminated surfaces).
"The 2003 SARS epidemic was containable because those affected generally became quite ill before they were particularly infectious, which limited the speed of spread (which distinguished this respiratory viral infection from influenza where people are infectious early in their illness).
"Fortunately, many of the methods developed for surveillance and control of pandemic influenza will also be useful for containing other respiratory virus epidemics, such as coronoviruses. These approaches still rely on core public health methods of disease surveillance, case isolation and quarantine of contacts, supported by high quality diagnostic laboratories and effective coordination and communication systems."
Dr Siouxsie Wiles, a microbiologist and infectious disease specialist at the University of Auckland blogs about the novel coronavirus here. She comments:
"After the SARS pandemic, it's not surprising that many are nervous about the emergence of a novel coronavirus (nCoV) in the Middle East. Since early 2012, there have been 34 confirmed cases of infection with nCoV, which causes severe acute pneumonia and renal failure. With 18 deaths so far, the case fatality rate currently sits at over 50%, a frightening statistic. But is this new coronavirus going to go pandemic, like the SARS virus did? With such a small number of cases to date, it is too early to say for sure.
"There are some big differences between the SARS pandemic and the cases of nCoV to date. The majority of nCoV cases have remained within Saudi Arabia and while there have been cases exported to Jordan, Qatar, the United Arab Emirates, the United Kingdom and France, the virus does not seem to have spread much beyond the index cases. There have been a small number of cases of family members becoming infected. This confirms that nCoV can transmit from person to person but suggests that prolonged exposure is needed to become infected, at least for healthy people.
"One of the interesting features of this novel coronavirus, is that the majority of infections have occurred within health care facilities, such as hospitals, as has just been reported in France. Those people were in hospital for a reason though, suggesting that some underlying disease may be required to make people more vulnerable to infection with nCoV.
"So far, the evidence is suggesting that nCoV is unlikely to turn into a pandemic. But the thing about viruses is that you never know. Scientists in Europe have shown that nCoV is highly infectious to human airway epithelial cultures in the laboratory, and that the virus can hide itself from the human immune system. But somehow this isn't currently translating into epidemic spread out in the real world. We shouldn't be complacent. It is certainly not inconceivable that nCoV could mutate in some way to become more infectious to healthy people, the first step towards a SARS-like scenario. And there is still so much we don't know about nCoV. Where did it come from? What is nCoV's natural reservoir?
"If nothing else, the emergence of nCoV is another warning of the threat we face from novel viruses. As many of these viruses cross over to humans from wild animals, these threats are going to increase as humans continue to encroach on the natural habitats of so many creatures. And our interconnected global world means any new virus is less than 24 hours away from anywhere else on earth.