REALITY CHECK
January saw a new virus emerge in the Chinese city of Wuhan. By the end of the month it had killed over 100 people, infected thousands more and had spread to other countries. Could it be the beginning of a pandemic?
We review the outbreak of the coronavirus in Wuhan, China. Is it cause for panic?
WHEN DID THE OUTBREAK START?
On 31 December 2019, China contacted the World Health Organization (WHO) to inform them of an outbreak of ‘pneumonia of unknown cause’ in Wuhan, a city in the country’s central Hubei province.
A week later, on 7 January 2020, the Chinese authorities investigating the outbreak confirmed that a previously unknown strain of coronavirus was to blame. It was believed to have originated in one of Wuhan’s animal markets, where it had jumped species from an as-yetunidentified animal into humans.
By 11 January the coronavirus, temporarily designated 2019-nCoV, had claimed its first life. Over the next 10 days, the news broke that human-to-human transmission of 2019-nCoV was possible. The virus killed two more people, and cases of it turned up in Thailand, Japan, South Korea, Vietnam and the US. WHO met to determine whether the situation constituted a global emergency.
As of Monday 27 January, less than a month after the initial alert, 10 cities in Hubei are in a state of lockdown and airports around the globe are screening passengers arriving from Wuhan. The virus has reached Australia and France, the number of confirmed cases is up to almost 3,000 and rising.
BUT HOW SERIOUS IS IT?
The 2019-nCoV virus presents with flu-like symptoms but is capable of causing respiratory distress, pneumonia and potentially death. Furthermore, it’s contagious before the symptoms show.
“It’s a serious situation. We’re approaching it with caution but I don’t think alarm,” says Prof Mark Fielder, a medical microbiologist at Kingston University. “What we need to remember is that most of the cases – in fact, I’m going to say all of the cases as things stand now – have come from people with direct links to Wuhan or other local cities where the virus is known to be present.”
According to Fielder, the virus hasn’t moved into people without direct links to Wuhan – it will be more concerning if that happens. Many people, once they are given supportive care, seem to fight the virus off and get better. “A number of the patients who unfortunately lost their lives have also had other diseases, so they’ve perhaps not been quite so fit in the first place,” says Fielder.
At the time of writing, the coronavirus is still spreading. But despite the seemingly steep rise in the number of cases, the outbreak remains within estimates of its expected incidence. WHO has put the total number of expected cases at 4,000, with a margin for error from 1,000 to 9,700.
“[The reason] we’ve seen a rise in the number of cases is, I think, a conglomeration of factors. If it did emerge from this market, which does seem likely, then obviously quite a lot of people attended that market, especially as people were probably getting provisions for the New Year celebrations in China,” explains Fielder. “But we can’t tell how many people were in that market and where they went afterwards or where they’d come from before. Also, it takes about five days for the symptoms to appear, so there would have been a delay from exposure to symptom formation. And perhaps we’re now seeing relatives of those infected, and people who have been caring for them, succumbing themselves.” The length of 2019-nCoV’s incubation period explains the sudden jump in the number of confirmed cases. Transmission may be slowing but cases will continue to appear due to the time it takes for the infection to present. Ensuring China has sufficient capacity to deal with the cases that are still to appear is why it’s currently rushing to build new hospitals.
WHY IS THERE SUCH A WIDE MARGIN OF ERROR?
The wide margin for error associated with WHO’s estimate
“Most of the cases have come from people with direct links to Wuhan or other local cities where the virus is known to be present”
suggests a lot of uncertainty. But the mathematical models that produced the estimate are deemed to be reliable – they’re the same ones used to anticipate and prepare for the annual outbreaks of influenza. “The margins are so wide because it’s so difficult to predict how much a virus will spread in a population, especially a respiratory-based virus,” says Fielder. “If the people in Wuhan adhere to the lack of gathering … they’re not going out and being in groups where somebody could easily cough, sneeze or do something else that spreads the virus inadvertently. Assuming those parameters are adhered to, contact will be less. If contact is less, then the chances of the virus spreading are decreased.
“But there has to be a reasonable margin of error because people may move around despite the fact they’ve been told not to. That’s the problem with dealing with humans, it’s difficult to guarantee that they’ll do what they’re asked.”
That ‘human element’ is partly why the lockdown in Wuhan and surrounding cities was deemed necessary. By introducing quarantine conditions, the authorities can limit the number of people 2019-nCoV is exposed to, which limits its ability to mutate into something more virulent and/or transmissible.
WILL IT REACH THE UK?
Matt Hancock, the Secretary of State for Health and Social Care, told Parliament in late January that it’s increasingly likely 2019-nCoV will turn up in the UK. The good news for anyone showing such symptoms, according to Dr Adam Kucharski, an associate professor in infectious disease at the London School of Hygiene, is that a diagnostic test for 2019-nCoV has already been developed. “One of the things that’s been remarkable in this outbreak is the speed at which the information required to develop a test has been made available. Very quickly we were seeing genetic information on this virus being shared and a lot of tools can be developed off the back of that.”
It seems then that as things stand, unless you’ve had contact with someone who has a respiratory disease who’s come from Wuhan or China, your chances of contracting the virus are low and if you do, then doctors will be able to help.