Scientists around the world have received threats of death and sexual assault after speaking to the media about Covid-19, a survey has revealed.

Of 321 scientists asked by Nature magazine, 15% said they had received death threats and 22% had been threatened with physical or sexual violence as a result of talking publicly about the pandemic.

Two-thirds said they had had a negative experience after appearing in the media.

Scientists disclosed how they had been left distressed and scared and in some cases stopped sharing their views publicly after experiencing harassment and intimidation.

The most common triggers for abuse were offering views on Covid vaccination, face masks, the origins of the Covid virus and the efficacy of drugs to treat the disease. They included ivermectin, an anti-parasite medication which has been championed by some of those who oppose Covid vaccination.

Dr Andrew Hill, a pharmacologist at the University of Liverpool, received images of hanged people and coffins after he and colleagues published a meta-analysis in July suggesting that ivermectin may help in treating Covid but then withdrawing the paper after having doubts about the data underpinning one of the studies they had analysed.

The scientists – mainly from the UK, Germany and the US – related how they had received abusive or threatening emails and messages, including threats to kill them or loved ones, made by email, phone call and social media, and had their home addresses published. Six of the 321 scientists who responded to the magazine’s survey said they had been the victim of a physical attack.

“I am shocked and saddened to hear that so many fellow scientists have experienced death threats or threats of physical or sexual violence, simply for doing their job trying to communicate the scientific facts that are so important for society in understanding and responding to this global health emergency”, said Dr Simon Clarke, an associate professor in cellular microbiology at Reading University who took part in the survey.

“I have had some bad experiences after appearing in the media, particularly after calling out conspiracy theorists and some politicians, who seem to dislike having their pet theories debunked. I have on occasion been threatened with various forms of death, violence and lifelong imprisonment.”

Clarke added that, while he has been able to ignore the threats, “I know some colleagues have had far worse experiences”. “I suspect that these negative experiences reflect a wider malaise in public discourse in society, fuelled by social media and growing social and political tribalism”, he added.

Nature surveyed scientists in seven countries who had appeared in the media talking about Covid after a poll of 50 scientists by the Australian Science Media Centre found that six (12%) had received death threats and another six (12%) been threatened with physical or sexual violence.

However, the magazine’s much larger sample found that higher proportions of scientists had been on the receiving end of abuse, hostility, verbal aggression or threats. More than two in five of the 321 respondents said they had experienced emotional or psychological distress as a result.

Scientists have previously been the subject of coordinated social media campaigns and threatening emails and phone calls after speaking out about the climate emergency, vaccination and gun violence, Nature says. “But even scientists who had a high profile before Covid-19 told Nature that the abuse was a new and unwelcome phenomenon tied to the pandemic”, it adds.

Dr Michael Head, a senior research fellow in global health at Southampton university, said: “There’s been a huge amount of abuse directed at everyone contributing to the pandemic response. The intensity of such harassment has gone up significantly across the pandemic, including becoming more organised and frightening than simply mindless comments on social media.”

Some scientists who were harassed told nature they no longer appear in the media to discuss Covid issues.

Fiona Fox, the director of the UK science media centre, said: “It’s a great loss of a scientist who was engaging with the media, sharing their expertise, is taken out of a public debate at a time when we’ve never needed them so badly.”