De Domenico filtered messages for emotional content, examining tweets for neuroticism and other psychological characteristics. He also scanned them for misinformation. What’s happened during the worldwide outbreak of the disease covid-19 is different from the “standard circulation of fake news,” he said. “The amount of unreliable news is a huge potential threat to public health.”

The World Health Organization, even before it declared the coronavirus outbreak to be a pandemic, labeled the onslaught of messages as an infodemic. “The covid-19 outbreak and response has been accompanied by a massive ‘infodemic’ — an overabundance of information, some accurate and some not — that makes it hard for people to find trustworthy sources and reliable guidance when they need it,” said Tarik Jasarevic, a spokesman for the World Health Organization.

There was trouble from the beginning. “The lack of good information in the first weeks gives oxygen to misinformation,” said Cristina Tardáguila, associate director for the International Fact-Checking Network. She has been debunking coronavirus claims since they first appeared around Jan. 24, when hoaxes flooded social networks in Asia.

Tardáguila said the coronavirus outbreak has provoked the strongest action from fact-checkers she’s ever seen. More than 90 fact-checking organizations banded together in response, Tardáguila said, representing nearly 40 countries, 15 languages and every time zone. (The network maintains a running Twitter list of its latest fact checks.)

The WHO is working with Twitter, Facebook and other platforms to restrict coronavirus misinformation. The organization also enlisted Instagram and YouTube influencers to spread accurate news.

De Domenico answered The Washington Post’s questions about social media messages while the scientist was isolated at his home in Italy. The following Q&A has been condensed and edited for clarity.

Q: In the United States, are there any unusual emerging trends?

A: After Feb. 15 to 20, we observed an unusual rise in the infodemic risk [caused by suspected bot activity and unverified-by-Twitter humans]. Infodemic risk is our indicator to quantify the rate at which a user in the online social system is exposed to unreliable information.

Overall, for the USA this risk is high when compared to other countries such as Singapore, [but recently] the infodemic risk is slightly decreasing for the USA.

Q: Does the artificial activity from bots seem to have a particular goal?

A: From the analysis of previous events, like the Catalan Referendum of Oct. 1, 2017, we have discovered that they tend to sustain online conflicts. [De Domenico observed a bot-driven spike in inflammatory messages in the weeks surrounding the vote for Catalonian independence.]

In practice, their only goal is to generate more chaos and confusion in the online social system. However, it is well known that this might have harmful consequences in the physical world: from political elections to finance, and now to public health.

Q: You’ve found that much of the sentiment is negative, particularly in certain countries. Do you see any trends?

A: I would rather say that the whole world is sad.

There are relationships between online sentiment, stock market changes and rise of confirmed cases. Of course, those relationships are only a proxy for very complex interdependencies between the social and the financial systems.

Q: You’re based in Italy, so if you don’t mind me asking, how has the coronavirus affected you?

A: In the last three weeks, I’ve had only a three-day break from voluntary isolation. [Italy recently moved from voluntary isolation to stricter lockdown rules, barring out-of-home activity with few exceptions.]

I feel lucky, because as a researcher I can work from home. With many difficulties — but I still can. But business is highly compromised from the local to national level. Stores and commercial activities are closed, with a huge impact on our economy.

And I have to mention our health system, with thousands of women and men working 24 hours a day in our hospitals close to saturation. They are exhausted. It is hard.

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