Misinformation and fake news on social media during infectious disease outbreaks, including the current novel coronavirus epidemic, can cost lives, according to researchers.

About 40% of people in the UK believe at least one conspiracy theory of some kind, say the researchers from East Anglia University. The figures are even higher in the United States and other parts of the world.

Their study, supported by Public Health England, looked at the impact of scare stories, rumours and false information about diseases such as norovirus, flu and monkeypox, shared on sites such as Twitter. It found that people who believed them were less likely to behave in a way that would protect themselves and others, such as washing their hands frequently and keeping away from other people if they have any symptoms.

Prof Paul Hunter, who is an expert on the new coronavirus infection, now called Covid-19, and Dr Julii Brainard, who are from UEA’s Norwich Medical School, said efforts to disseminate correct information across social media and correct the false stories could save lives.

Hunter said: “Fake news is manufactured with no respect for accuracy, and is often based on conspiracy theories.

“When it comes to Covid-19, there has been a lot of speculation, misinformation and fake news circulating on the internet – about how the virus originated, what causes it and how it is spread.

“Misinformation means that bad advice can circulate very quickly – and it can change human behaviour to take greater risks.

“We have already seen how the rise of the anti-vax movement has created a surge in measles cases around the world.

“People in west Africa affected by the Ebola outbreak were more likely to practise unsafe burial practices if they believed misinformation. And here in the UK, 14% of parents have reported sending their child to school with symptoms of contagious chickenpox – violating school policies and official quarantine advice.

“Examples of risky behaviour during infectious disease outbreaks include not washing hands, sharing food with ill people, not disinfecting potentially contaminated surfaces, and failing to self-isolate.

“Worryingly, people are more likely to share bad advice on social media than good advice from trusted sources such as the NHS, Public Health England or the World Health Organization.”

The researchers looked at the effect of two strategies for combating the fake news. One was to reduce the amount of misinformation on social media. The other was to educate people to recognise false information when they saw it – something they call “immunising” people against it.

Both tactics had some success, said Brainard. “But while we used very sophisticated simulation models, it is important to remember that this is not an observational study based on real behaviour,” she said.

“The efficacy of implementing such strategies to fight fake news needs to be tested in real-world settings, with costs and benefits ideally compared with real-world disease reduction.”