Medical experts have said they fear that Brazil’s president, Jair Bolsonaro, could be hastening the country’s march towards a devastating public health crisis like those to have hit northern Italy and New York by undermining social distancing measures.

Bolsonaro is one of just four world leaders still downplaying the threat of coronavirus to public health, alongside the authoritarian presidents of Nicaragua, Belarus and Turkmenistan.

Over Easter, Brazil’s far-right leader repeatedly sniffed at his own health ministry’s distancing recommendations by going out for doughnuts, glad-handing fans and proclaiming: “No one will hinder my right to come and go.” During one outing, Bolsonaro was filmed wiping his nose with his wrist before shaking an elderly lady’s hand.

Specialists in public health and infectious diseases believe such behaviour is eroding the only measures standing between Brazil – which has suffered more than 1,000 Covid-19 deaths – and a healthcare calamity.

Facebook Twitter Pinterest Police officers wearing protective masks patrol the Rocinha slum in Rio de Janeiro. Photograph: Ricardo Moraes/Reuters

“It’s as if everybody’s on the same train heading towards a cliff-edge and someone says: ‘Look out! There’s a cliff!’ And the passengers shout: ‘Oh no there isn’t!’ And the train driver says: ‘Yeah, there’s nothing there!’” said Ivan França Junior, an epidemiologist from the University of São Paulo’s faculty of public health. “My sadness stems from seeing avoidable deaths that we are not going to avoid.”

Marcos Lago, an infectious diseases specialist at Rio de Janeiro’s Pedro Ernesto University Hospital, said Bolsonaro’s reckless conduct was confusing people over the need to stay at home.

“He’s making a very dangerous bet … that Brazil won’t behave like the US, like England, like Italy. I think that’s an irresponsible bet because there’s a very big chance a catastrophe will happen and the chance of one not happening is very small.”

A third doctor, who asked not to be named, called Bolsonaro’s actions “childish” and “surreal”. “It’s madness. There’s no justification for this kind of behaviour,” they said. “You can justify thinking about the business community. It’s cool to try and find [economic] solutions [to this crisis]. What’s not cool is ignoring what all of the world’s top epidemiological experts are saying.

“People are going to get sick [in Brazil], and if they get sick at the same time we will find ourselves in the same situation as Italy and Wuhan.”

Since mid-March, the governors of nearly all of Brazil’s 27 states have been trying to slow transmission by ordering citizens indoors. But there are signs that such efforts are fraying, with a growing number of people stepping out on to the streets of cities such as Rio and São Paulo.

The experts point to several possible explanations for falling adherence to social distancing in Brazil. One was the failure of state governments to sufficiently support poor favela residents who had no option but to work. Another was the difficulty in persuading exuberant, family-focused Brazilians to shun relatives.

“Brazilians are having a really hard time with social distancing. We aren’t used to this. We’re used to living together, to hugging and kissing each other,” said Tânia Vergara, president of Rio’s Society of Infectious Diseases.

“Some people can’t bear this, so perhaps we need tougher measures,” Vergara ventured, before adding: “But we have a president who isn’t sticking to the measures himself.”

There is also consensus that by snubbing distancing, Bolsonaro is undercutting its implementation. “Everything he says and does has an intense impact … Lots of people say: ‘The president’s 65 and he’s not afraid – so why should we be?’” said Ricardo Sobhie Diaz, an infectious diseases specialist from São Paulo’s Federal University. “Everybody [in infectiology] thinks the same about the president: that he’s not going in a good direction.”

Alberto Chebabo, vice-president of the Brazilian Society of Infectious Diseases, said because coronavirus arrived in Brazil later than elsewhere, it had the advantage of learning from other countries’ experience – and had the chance to take crucial steps such as distancing. “We can see the epidemic is advancing more slowly [here] and if it’s advancing more slowly it’s because of these measures,” he said.

But Bolsonaro’s stance risked throwing away that advantage. “We need a unified discourse,” Chebabo added.

Polls show that the president still enjoys the backing of about 30% of voters, and hundreds turned out in São Paulo on Saturday to denounce social distancing. “The hospitals are empty,” one supporter, who gave his name as Wagner de Oliveira, falsely claimed during a two-man pro-Bolsonaro demo in Rio.

But media and politicians of all stripes have rounded on the president. “President Bolsonaro is the virus’s main ally,” said Arthur Virgílio, mayor of the Amazon city of Manaus, where 42 people have died.

Merval Pereira, a columnist for the O Globo newspaper, accused Bolsonaro of acting like “a mystical leader leading his followers to collective suicide”.

França Junior predicted painful days lay ahead: “We are going to see people dying outside hospitals [because there are no intensive care beds], people dying at home because our ambulance service won’t be able to cope.

“Forecasts suggest this will happen in three or four weeks … and by then it will be too late. People will freak out and lock themselves indoors of their own volition.”