Coronavirus – Credit CDC PHIL
The news yesterday that a third member of the same family has contracted the novel coronavirus (see HPA: UK NCoV Cluster Expands To Three Cases) has prompted this third update of the past week from the World Health Organization’s GAR (Global Alert and Response) Network.
First the WHO Update, then I’ll return and try to put the events of this week into perspective.
16 February 2013 - The United Kingdom (UK) has informed WHO of another confirmed case of infection with the novel coronavirus (NCoV). This is the third case confirmed in the country this month and is in the same family cluster as the two recently confirmed cases.
The latest confirmed case does not have recent travel history outside the UK. The case is recovering from mild respiratory illness and is currently well.
The confirmation with NCoV in this case with no recent travel history indicates that infection was acquired in the UK. Although this new case offers further indications of person-to-person transmission, no sustained person-to-person transmission has been identified.
The Health Protection Agency (HPA) is following up on all close contacts who may have been exposed to the recently confirmed cases.
As of 16 February 2013, WHO is informed of a total of 12 confirmed cases of human infection with NCoV, including five deaths.
Based on the current situation and available information, WHO encourages all Member States to continue their surveillance for severe acute respiratory infections (SARI) and to carefully review any unusual patterns. Testing for the new coronavirus should be considered in patients with unexplained pneumonias, or in patients with unexplained severe, progressive or complicated respiratory illness not responding to treatment.
Any clusters of SARI or SARI in healthcare workers should be thoroughly investigated, regardless of where in the world they occur.
New cases and clusters of the NCoV should be reported promptly both to national health authorities and to WHO.
WHO does not advise special screening at points of entry with regard to this event nor does it recommend that any travel or trade restrictions be applied.
WHO continues to closely monitor the situation.
We will probably see an epidemiological update and a revised EU Risk Assessment from the ECDC on this cluster over the next few days as well.
This story has prompted considerable global media attention and speculation, and while the potential certainly exists for a greater global impact, it is worth noting that most of the time when novel viruses manage to jump to humans, they sputter briefly and then recede.
Last August in Novel Viruses & Chekhov’s Gun, I went over some of these viral `pretenders’ that have tried, and thus-far failed, to establish themselves in the human population.
Of course, today’s failure is no predictor of what may happen tomorrow.
Viruses – particularly RNA viruses – evolve at a tremendous rate. Meaning we should not be lulled into complacency simply because an emergent virus fails to make it in the human species on its first few attempts.
Sometimes the only ingredients they need are more time and more opportunities. Of course, sometimes it never happens, no matter how many chances the virus gets.
Seventeen years after the H5N1 virus was first detected in Hong Kong, we remain alert to the possibility that it could become a `humanized’ influenza. That risk will likely remain with us for years to come.
And the future with this emerging coronavirus is equally unknowable.
NCoV may simply continue to make brief but dramatic jumps to humans - much as Nipah, Hendra, H5N1, Lyssavirus, Ebola, and Marburg have done - or it might disappear completely over time.
Perhaps least likely, but certainly not beyond the realm of possibility, we could see NCoV adapt well enough to human physiology to pose a genuine global health threat.
While that sort of worst case outcome is always in the back of our minds, it is somewhat reassuring if you remember:
While all pandemics are caused by novel viruses, not all novel viruses produce pandemics.
Of course, the flip side to this logic is we know that another pandemic will almost certainly occur, we just don’t know when, or from what source.
So we watch emerging viruses like NCoV closely, not because we are convinced it represents the `next big one’ - but because we know that someday - a virus will come along that does.