Bolsonaro, an outlier among world leaders in his skepticism of both the coronavirus and preventive measures intended to curb it, was tested Monday evening after developing symptoms that included a fever.
"There's no problem," he told reporters Tuesday. "It's natural. There's no dread. It's life."
The result adds one more case to what has become the world's second-worst coronavirus outbreak, after the United States. Brazil has reported more than 1.6 million cases and 65,000 deaths - both believed to be undercounts - an escalating disaster that scientists and health officials say has been exacerbated by Bolsonaro's frequent dismissal of it.
Bolsonaro, 65, has described covid-19 as a "little cold," repeatedly waded into crowds of supporters, threatened to host a large barbecue to defy health measures, and as recently as last week attended a Fourth of July party at the U.S. Embassy in Brasilia without wearing a mask. A Brazilian court last month ordered Bolsonaro to wear a mask while in public.
"In my particular case," the former army officer said in a national address in March, "with my history as an athlete, if I were infected by the virus, I wouldn't need to worry. I wouldn't feel anything or, if very affected, it would be like a little flu or little cold."
Bolsonaro is at least the fourth world leader to test positive for covid-19. British Prime Minister Boris Johnson was treated in intensive care in April; he has since recovered. Guinea-Bissau's Prime Minister Nuno Gomes Nabiam tested positive in April. Honduran President Juan Orlando Hernández was hospitalized last month. He announced last week he was leaving the hospital and resuming work.
Wearing a mask at a news conference with reporters huddled near him, Bolsonaro disclosed that he had contracted the highly infectious and potentially fatal virus.
Despite the positive test result, he repeated the same talking points he has used since the beginning of the pandemic. He said some of the preventive measures have been exaggerated, urged Brazilians to prioritize the economy and said young people have almost no need to worry if they catch the disease. Scientists strongly disagree.
"Life will continue, and Brazil needs to produce," he said. "If the economy isn't functioning, it will create other problems that will lead to more death."
He said he planned to continue working in isolation but has canceled travel.
At the end of the conference, he stepped several feet away and removed his mask to address the reporters.
"I'm good, relaxed," he said. "Let's be cautious with people who are older and have co-morbidities, and for people who are younger, if you get the virus, stay calm. Because for you, the chance of it being more grave is practically zero."
But data scientists say the situation in Brazil is much more complicated. Among the young, Brazil has a significantly higher mortality rate than its developed peers. In Rio de Janeiro state, more than two-thirds of hospitalizations are of people younger than 50.
U.S. Ambassador Todd Chapman, who hosted Bolsonaro at the July 4 barbecue, has tested negative for the virus and is now in quarantine at home, the embassy tweeted Tuesday. Images shared on social media showed Bolsonaro and Chapman arm-in-arm at the event, without masks. Other embassy officials who might have been exposed are being tested.
The embassy did not immediately respond to questions about policies on masks. Mask use at U.S. embassies is at the discretion of individual ambassadors, State Department employees say. A department spokesperson said Chapman was "taking appropriate precautions," and all embassy staff must follow the protocols of the U.S. Center for Disease Control and Prevention.
Bolsonaro, a former fringe politician who won the presidency in 2018 on a message of cracking down on crime and corruption, has lost significant political support since the start of the pandemic. Former allies have turned against him. The middle class, which had been his base, has increasingly disapproved of him. Some of the most powerful voices in the country have called for his impeachment or resignation.
Adding to the uncertainty has been the persistent guessing game of whether Bolsonaro had the coronavirus. In March, his communication secretary tested positive for the virus after President Donald Trump hosted Bolsonaro, the secretary and others at a dinner at Mar-a-Lago. It sparked intense speculation - and widely shared inaccurate news accounts - that Bolsonaro had contracted the virus.
Even after Bolsonaro said he had tested negative - twice - skepticism persisted. More than a dozen members of his presidential envoy had tested positive for the virus. He refused to release his test results until he was ordered to do so by a court.
Late last month, he again wondered aloud whether he did have the coronavirus and said he intended to take another test.
He has meanwhile urged Brazilians to disobey local orders to close businesses and self-isolate. He is on his third health minister since the start of the pandemic. He fired the first after clashing over the need for social isolation. Then he pushed out the second, who had disagreed with Bolsonaro over liberally using the anti-malarial drug hydroxychloroquine to treat virus patients.
Bolsonaro next installed a military man who is not a doctor.
Without a coordinated federal strategy, the country has drifted. Governors and mayors have been left to make decisions on their own, often in conflict with Bolsonaro's desire to keep the economy open. Responses did not vary only among states and cities, but neighborhood by neighborhood. The disorganization has abetted widespread contamination and left many Brazilians unsure of which officials to trust.
In recent weeks, cities have started to reopen. Scientists now fear that cases in the coming weeks will surge higher as bars, restaurants and other meeting places fill up once more.