When reports of a new coronavirus emerged last month, I speculated with fellow epidemiologists about what the media might end up naming the infection. None of us would have guessed that within a week or so a theory would be circulating that coronavirus was a new kind of “snake flu”– mostly because it’s unlikely the virus originated in snakes, and it’s not flu.
So where did the snakes come from? The culprit was a widely shared scientific paper, which speculated that the new virus had genetic characteristics and implicated snakes as the source. Leading geneticists were quick to point out that the results weren’t convincing, and that bats were still the likely suspects. However, that didn’t stop snake flu from going viral. Other misinformation about coronavirus has rippled across the internet in recent weeks. From claims the virus is part-HIV to conspiracy theories about bioweapons and reports suggesting the virus was linked to people eating bat soup, stories sparking fear seem to have overtaken the outbreak in real life. Is misinformation really more contagious than the virus itself?
What is the virus causing illness in Wuhan?
It is a member of the coronavirus family that has never been encountered before. Like other coronaviruses, it has come from animals. Many of those initially infected either worked or frequently shopped in the Huanan seafood wholesale market in the centre of the Chinese city.
What other coronaviruses have there been?
New and troubling viruses usually originate in animal hosts. Ebola and flu are other examples – severe acute respiratory syndrome (Sars) and Middle Eastern respiratory syndrome (Mers) are both caused by coronaviruses that came from animals.
What are the symptoms of the Wuhan coronavirus?
The virus causes pneumonia. Those who have fallen ill are reported to suffer coughs, fever and breathing difficulties. In severe cases there can be organ failure. As this is viral pneumonia, antibiotics are of no use. The antiviral drugs we have against flu will not work. If people are admitted to hospital, they may get support for their lungs and other organs as well as fluids. Recovery will depend on the strength of their immune system. Many of those who have died were already in poor health.
Is the virus being transmitted from one person to another?
Human to human transmission has been confirmed by China’s national health commission, and there have been human-to-human transmissions in the US and in Germany. As of 8 February, the death toll stands at 722 inside China, one in Hong Kong and one in the Philippines. Infections inside China stand at 31,161 and global infections have passed 280 in 28 countries. The mortality rate is 2%.
The number of people to have contracted the virus could be far higher, as people with mild symptoms may not have been detected. Modelling by World Health Organization (WHO) experts at Imperial College London suggests there could be as many as 100,000 cases, with uncertainty putting the margins between 30,000 and 200,000.
The number of confirmed cases of coronavirus in the UK has doubled from four to eight after four more people in Brighton were diagnosed with the infection over the weekend. One of the men is a doctor who was part of a group that were skiing in the resort near Chamonix with the man who is at the centre of the Brighton outbreak.
One of the other four confirmed cases is being treated at the HCID unit at the Royal Free hospital in north London and the two Chinese nationals who tested positive for Coronavirus in York are being treated at the HCID centre in Newcastle.
Why is this worse than normal influenza, and how worried are the experts?
We don’t yet know how dangerous the new coronavirus is, and we won’t know until more data comes in. The mortality rate is around 2%. However, this is likely to be an overestimate since many more people are likely to have been infected by the virus but not suffered severe enough symptoms to attend hospital, and so have not been counted. For comparison, seasonal flu typically has a mortality rate below 1% and is thought to cause about 400,000 deaths each year globally. Sars had a death rate of more than 10%.
Should I go to the doctor if I have a cough?
Unless you have recently travelled to China or been in contact with someone infected with the virus, then you should treat any cough or cold symptoms as normal. The NHS advises that people should call 111 instead of visiting the GP’s surgery as there is a risk they may infect others.
Is this a pandemic and should we panic?
Health experts are starting to say it could become a pandemic, but right now it falls short of what the WHO would consider to be one. A pandemic, in WHO terms, is “the worldwide spread of a disease”. Coronavirus cases have been confirmed in about 25 countries outside China, but by no means in all 195 on the WHO’s list.
There is no need to panic. The spread of the virus outside China is worrying but not an unexpected development. The WHO has declared the outbreak to be a public health emergency of international concern, and says there is a “window of opportunity” to halt the spread of the disease. The key issues are how transmissible this new coronavirus is between people and what proportion become severely ill and end up in hospital. Often viruses that spread easily tend to have a milder impact.
Sarah Boseley Health editor and Hannah Devlin
We typically think of viral content as a chain reaction: you share something with friends, they share it with their friends, and so on. In disease outbreak analysis, we can measure the transmission of an infection by looking at how many additional cases each infected person creates on average during each of these steps. We call this the “reproduction number”, and for coronavirus, we estimate it’s about 2 for a typical infected case in China. What about the reproduction number for online content? A couple of years ago, Facebook researchers looked at the most shared content on the platform from 2014 to 2016, including viral trends such as the ice-bucket challenge and putting an equals sign over your profile picture to support marriage equality.
Remarkably, there wasn’t much difference in the transmission. Researchers found the reproduction number was about 2 for all of them. Remember, these were the most shared ideas on Facebook; the vast majority of online content is lucky to get even a single repost.
To fully explain how viral content – and viruses – spread, we need to move away from the idea that outbreaks involve simple clockwork infections, passing along a chain from person to person to person until large numbers have been exposed. During the 2015 outbreak of the Mers coronavirus in South Korea, 82 out of 186 infections came from a single “superspreading event” in a hospital where an infected person was being treated. It’s not yet clear how common such superspreading is in the current outbreak, but we do know that these kinds of events are how information goes viral online; most outbreaks on Twitter are dominated by a handful of individuals or media outlets, which are responsible for a large proportion of transmission. If you heard about snake flu, you might have told a couple of friends; meanwhile, newspaper headlines were telling millions.
When tackling disease outbreaks, health agencies often work to identify potential superspreading events, isolating infected individuals to prevent further transmission. However, this isn’t the only way to stop an outbreak. As well as tracking down people who are infectious, it’s possible to target broader social interactions that might amplify transmission. For example, many cities in China have recently closed schools, which can be hotspots for respiratory infections.
Tech companies are now adopting similar approaches to tackle health misinformation. Last year, Pinterest announced it had rewired its search results to make it harder to find vaccine misinformation. It had struggled to remove the content completely – the equivalent of finding all the cases during a disease outbreak – so instead focused on reducing how many people might be exposed to harmful content. During the current outbreak, Google is attempting to reduce people’s susceptibility to misinformation by displaying links to reputable health sources when users search for information about the virus.
These combined approaches, which target different aspects of transmission, have long been used in disease control. By introducing analogous strategies online, we should have a better chance of effectively curbing harmful viral content.
Ensuring the public has the best possible health information is crucial during an outbreak. At best, misinformation can distract from important messages. At worst, it can lead to behaviour that amplifies disease transmission. The novelty of coronavirus makes the challenge even greater, because viral speculation can easily overwhelm the limited information we do have. The scientific community is already making huge progress in understanding the infection, but we’ve had to start at the bottom, without stacks of earlier research to stand on. When it comes to stopping the outbreak, we’ll need ladders, not snakes.
• Adam Kucharski an epidemiologist and the author of The Rules of Contagion: Why Things Spread – and Why They Stop, published on 13 February
