As the world approaches the first anniversary of the pandemic, Covid-19 continues to leave a trail of death and despair in Brazil, pushing hospitals to the brink as the spread of a more contagious "mutant" strain threatens reinfection.

One of the hardest-hit countries globally — second only to the United States in its death toll and third in the world for infections — close to 11 million residents have contracted the virus while more than a quarter of a million have died.

While Covid-19 is slowly beginning to recede in other nations — even those where major outbreaks have occurred — as vaccine rollouts begin, Brazil is battling a spike in new cases and record-setting death tolls.

Up to 80 per cent of ICU beds are filled in around 20 states.

The National Council of Health Secretaries is calling for a national curfew and closure of airports to avoid a collapse of both the public and private healthcare systems.

"The acceleration of the epidemic in various states is leading to the collapse of their public and private hospital systems, which may soon become the case in every region of Brazil," the association said.

Brazil's health system is stretched to the limit. Photo / AP

"Sadly, the anaemic rollout of vaccines and the slow pace at which they're becoming available still does not suggest that this scenario will be reversed in the short term."

It doesn't help matters that President Jair Bolsonaro — who has downplayed the pandemic and its consequences almost since it began — continues to do so, railing against face masks and telling residents to "stop whining", 24 hours after 1910 people died from the virus in a single day.

"How long are you going to keep crying about it?" the far-right leader said at an event on Friday.

"How much longer will you stay at home and close everything? We regret the deaths, again, but we need a solution."

His conduct, Sao Paulo governor João Doria told the BBC, means that "Brazil has to fight, at this moment, two viruses: the coronavirus and Bolsonaro virus. This is a sadness for the Brazilians".

Doria called the President "a crazy guy" for attacking "governors and mayors who want to buy vaccines and help the country to end this pandemic".

"How can we face the problem, seeing people die every day? The health system in Brazil is on the verge of collapse," he added.

A nurse at a Manaus hospital, Maria Glaudimar, told The New York Times patients and their relatives were pleading for oxygen and all intensive care beds were full, describing the situation as "horror film" that "no one was prepared for".

"We should be vaccinating more than a million people per day," pulmonologist Margareth Dalcolm at prominent scientific research centre Fiocruz told The Times.

"That is the truth. We aren't, not because we don't know how to do it, but because we don't have enough vaccines."

It's not just Brazil that should be worried, though, by the continually unfolding crisis, experts have warned.

Speaking to The Guardian, Duke University neuroscientist Miguel Nicolelis urged the international community to challenge the Brazilian government over its failure to contain Covid-19.

"The world must vehemently speak out over the risks Brazil is posing to fight against the pandemic," he told the publication, having tracked the crisis over the last 12 months.

"What's the point in sorting the pandemic out in Europe or the United States, if Brazil continues to be a breeding ground for this virus?

"We've now gone past 250,000 deaths, and my expectation is that if nothing is done we could have lost 500,000 people here in Brazil by next March. It's a horrifying and tragic prospect, but at this point it's perfectly possible."

A "mutant" strain that originated in the South American nation and has already been detected in other countries around the world is also cause for concern, he added, calling Brazil "an open-air laboratory for the virus to proliferate and eventually create more lethal mutations".

"This is about the world. It's global."

The new variant, known as P. 1, is 1.4 to 2.2 times more contagious than versions of the virus previously found in Brazil, and 25 per cent to 61 per cent more capable of reinfecting people who had been infected by an earlier strain, according to a study released last Tuesday.

The strain has been found in 21 of 26 Brazilian states, with doctors and nurses reporting that colleagues who had recovered from the virus months ago and contracted it again and tested positive.

Led by professor of virus evolution at Oxford University and Imperial College London, Nuno Faria, the research is yet to determine "whether the estimated increase in relative mortality risk is due to P. 1 infection, stresses on Manaus healthcare system, or both".

"The virus is behaving differently," intensive-care doctor Rosa Lopez told The Wall Street Journal.

"It's really aggressive … the situation is very difficult, really terrible."

text by Natalie Brown, news.com.au