As the numbers of known coronavirus cases around the world continue to sharply increase, countries are enforcing travel restrictions, sealing off towns to prevent local transmission, and in some cases suspending public transport and cancelling sporting matches. So how worried should you be and how far and for how long with the coronavirus spread?
While the World Health Organization (WHO) is yet to declare the coronavirus (COVID-19) a pandemic, which they define as “the worldwide spread of a new disease”, the former chair of the Global Health Council and global health expert Jonathan D Quick, suggests that the worst-case scenario for the coronavirus is likely to occur.
From what we know at the moment, the coronavirus kills roughly 2% of those afflicted. This isn’t as high a death rate as some other viruses like Ebola which had an average death rate of 50%, however the coronavirus spread at a much faster rate than many other viruses.
The number of undetected cases passing across borders has highlighted the imperfect nature of travel restrictions and disease screening, but if we don’t enforce travel restrictions what else can we do to stop the virus spreading?
Unfortunately no matter how hard you try, borders are leaky when it comes to viruses. It’s made more difficult when viruses take a number of days before people start to show symptoms. In the case of coronavirus it’s about 5 days before you may see symptoms but patients are contagious before these symptoms appear. This means people may spread the virus before knowing they have it. The mild nature of symptoms relating to the coronavirus also make detection more difficult. People are unaware of the severity of their illness and take longer to recognise their illness as the coronavirus. Other viruses like Ebola or SARS both had more severe symptoms making detection easier, they were also not as easily transmitted between people allowing the viruses to be brought under control relatively quickly in comparison.
Reported cases of coronavirus by country (numbers of cases of coronavirus as reported in NY Times, 2 March 2020, https://www.nytimes.com/interactive/2020/world/coronavirus\-maps.html\).
The timing of when people become contagious and recognise symptoms is important because this helps us understand if changes in travel policy will aid in keeping a virus from crossing borders. In the case of the Novel coronavirus, the lock down in Wuhan arrived too late with the virus having already spread to other parts of mainland China. In fact the delayed travel ban enforced on travellers from Wuhan and Hubei Province may have given a false sense of security to other countries and regions with them allowing travellers from other parts of China to move freely. We now realise that some of these people were most likely infected while travelling. If anything the Wuhan lockdown delayed the global progression of the coronavirus by around three to five days but didn’t stop the spread in the long run.
In extreme cases any sort of lockdown or harsh travel bans can actually force the disease to spread as we saw on the Diamond Princess cruise ship. For two weeks the cruise ship was quarantined off Japan’s coast with around 3,700 passengers and crew trapped inside. Initially there were only 10 people were diagnosed with coronavirus but this quickly increased to over 600 cases due to the enforced close quarters. Ideally they should have been permitted to disembark and be in solitary isolation so has not to infect each other or anyone else. Instead the virus thrived in a giant incubator.
Methods for testing people at airport customs and border checkpoints aren’t any more reliable. Taking a person’s temperature isn’t foolproof with measurement tools not always registering elevated body temperatures. The other factor is that you can’t necessarily rely on people to honestly tell you about the possible exposure they’ve had to the virus. Add all these factors together and it makes controlling the spread of a disease like coronavirus fairly difficult.
So what can you do to stop the coronavirus?
WHO is warning that countries need to be prepared for the spread of the virus even if they don’t yet have any reported cases. The spread is going to continue for some time before we see any sort of decline and countries need to have plans in places for prevention, detection and management, particularly less developed countries with weaker health infrastructure.
If the coronavirus does continue to spread as widely as is predicted, developing a vaccine will be crucial, especially when it comes to protecting more vulnerable populations. But until we learn more about the virus it appears that only old-school public health measures will help – isolation, quarantine and contact tracing. Basically the best way to prevent illness is to avoid being exposed to the virus.
Find out more about how you can prevent the spread of respiratory diseases from the Centers for Disease Control and Prevention.