She still gets surprised when people want to hug her at the supermarket, but her studious media appearances analyzing the pandemic have suddenly made Dr. Margareth Dalcolmo famous in coronavirus-ravaged Brazil. 

Dalcolmo, a 65-year-old pulmonologist and researcher at public health institute Fiocruz, was little-known to the general public when Covid-19 arrived in Brazil in February 2020.

But the soft-spoken expert has since made hundreds of media appearances on the health crisis, emerging as a comforting, almost motherly source of information in a country where disinformation and science-bashing are spreading as fast as the virus.

It all started in March last year, when Dalcolmo made a short video summarizing a crisis-response meeting she had just attended in the capital, Brasilia. "I knew nothing about social media at that point. But it got 1.5 million views," she said.

She has since become omnipresent on Brazilian TV and other media, one of the most listened-to voices on the pandemic in a country where more than 270,000 people have died of Covid-19 -- the world's second-highest death toll, after the United States.

Radiating calm authority with her red horn-rimmed glasses, she preaches the gospel of face masks, social distancing and vaccines, while denouncing mismanagement and corruption by health officials.

She has also pulled no punches in criticizing "absurd, inept" views, such as arguments against vaccines or in favor of the medication hydroxychloroquine.

That has placed her squarely opposite a powerful figure who has repeatedly made both claims: far-right President Jair Bolsonaro.

Dalcolmo has made 440 media appearances in all, giving her the name recognition typically reserved for, say, a superstar footballer.

"People are talking more about Margareth Dalcolmo than Neymar," columnist Zuenir Ventura wrote in newspaper Globo last month.