On 15 February the director-general of the World Health Organisation (WHO), Tedros Adhanom Ghebreyesus, addressed the Munich Security conference. At that moment, there were 66,000 cases of Covid-19 in China, and only 505 in the rest of the world. So most of us were probably still assuming that this was predominately a Chinese problem. This view was not shared by the WHO director-general. He was also concerned about: the lack of urgency in the international community; the severe disruption in the market for personal protective equipment, which was putting health workers at risk; the levels of rumours and misinformation that were hampering the response; and the havoc the virus could wreak in countries with weaker health systems.

The part of his speech that made me sit up, though, was this: “We’re not just fighting an epidemic; we’re fighting an infodemic. Fake news spreads faster and more easily than this virus, and is just as dangerous.” And if we don’t tackle this, he went on, “we are headed down a dark path that leads nowhere but division and disharmony”.

As if to underscore that point, up popped two stories this week. The first was a Buzzfeed report of what mis- and disinformation did to a small Ukrainian village. Two days of chaos and riots illustrated what can happen when people don’t trust their government but instead believe rumours and misinformation spread on social media. On 18 February a plane from Wuhan, China, had arrived in the country, and rumours started circulating that several of the 45 Ukrainians and 27 foreign nationals on board were infected with Covid-19. Upon landing, they were to be immediately bused to an undisclosed medical facility. A government announcement said that the evacuees had all been tested and none of them were infected. So there was nothing to worry about.

But, Buzzfeed reports, in the small town of Novi Sanzhary, residents went beserk when they discovered that the evacuees were going to be housed in their local sanatorium. Barricades were erected and fires set to try to keep the buses carrying the evacuees out of town. Protesters were met by phalanxes of police in riot gear who arrived with armoured vehicles to push them back. Tensions escalated, violent clashes broke out. And when the buses carrying people from China finally arrived, residents shouted at them to “get out” and hurled stones that shattered the windows.

When tempted to share a snippet of 'information' on Covid-19 that’s popped into your social media feed – don’t

The second story concerned polarisation. Some polling research in the US last week showed that Democrats and Republicans have starkly divergent views on the danger that the virus poses, and on how the Trump administration is handling it: 43% of respondents approve of Trump’s response to Covid-19, while 49% disapprove. But the divide falls largely along party lines – 83% of Democrats disapprove of Trump’s response, while 87% of Republicans approve, and two-thirds of Democrats are “very or somewhat concerned” about the virus, compared with just 35% of Republicans. Clearly Republicans don’t yet realise that the Covid-19 is no respecter of party affiliations.

One of the things that makes this epidemic different from predecessors is the dominance of social media in today’s world. One of the most perceptive analyses of what’s going on has come from Kate Starbird of Washington State University, who’s a leading expert on “crisis informatics” – the study of how information flows in crisis situations, especially over social media. Crises always generate levels of high uncertainty, she argues, which in turn breeds anxiety. This leads people to seek ways of resolving uncertainty and reducing anxiety by seeking information about the threat. They’re doing what humans always do – trying to make sense of a confusing situation.

In the pre-internet era, information was curated by editorial gatekeepers and official government sources. But now anything goes, and sense-making involves trying to find out stuff on the internet, through search engines and social media. Some of the information gathered may be reliable, but a lot of it won’t be. There are bad actors manipulating those platforms for economic gain (need a few face-masks, guv?) or ideological purposes. People retweet links without having looked at the site. And even innocently conceived jokes (a photograph of empty shelves in a local supermarket, for example) can trigger panic-buying.

In the absence of a vaccine, the only way of slowing the spread of the virus is by “social distancing” – ie stopping people congregating as much as possible. As the political theorist Yascha Mounck pointed out recently, distancing was just about the only thing that worked with the 1918 Spanish flu epidemic. And in the online world, maybe we need something analogous. How about a bit of self-discipline? Whenever you’re tempted to share a dramatic snippet of “information” about Covid-19 that’s just popped into your social media feed – don’t. Just say no. You’ll feel better, and you’ll be slowing the propagation of a pernicious meme – which, after all, is just another kind of virus.

What I’m reading

Pass it on…

Why does the coronavirus spread so easily between people? Illuminating article in Nature.

Mathematical memoir

Lunch with Freeman Dyson. A nice memoir of a brilliant physicist and a great explainer.

Invisible enemy

James Meek’s London Review of Books review of Dorothy Crawford’s great book about viruses. Published in 2001, but suddenly relevant again.