Brazilian President Jair Bolsonaro said on Tuesday he tested positive for the novel coronavirus, after months of playing down the severity of the virus which he has called a "little flu."
The right-wing populist said in an interview broadcast on state-run TV Brasil that he was in good health despite running a fever.
Bolsonaro said he took the test on Monday after feeling ill the previous day and has been taking hydroxychloroquine, an anti-malarial drug with unproven effectiveness against COVID-19.
The positive test looks set to spark a frantic period of contact tracing and further tests for those who met Bolsonaro in recent days, including Economy Minister Paulo Guedes, Brazilian bank Bradesco's Chairman Luiz Carlos Trabuco and planemaker Embraer's CEO Francisco Gomes Neto.
Over the weekend, Bolsonaro was also in close contact with US Ambassador Todd Chapman during July 4 celebrations. Pictures showed neither wearing a mask.
Brazil has the world's second-largest outbreak behind the United States. Latin America's largest country has more than 1.6 million confirmed cases and 65,000 COVID-19 deaths.
Bolsonaro joins a short list of heads of government to become infected with the coronavirus, including British Prime Minister Boris Johnson and Honduran President Juan Orlando Hernandez, both of whom were treated in hospital and needed extra oxygen.
Pan American Health Organization director for communicable diseases Marcos Espinal wished Bolsonaro a "speedy recovery" but said his infection carried a message.
"The message is that this virus is unpredictable and does not respect race, class or people in power, despite security around any president," Espinal said.
"For Brazil, the infection of its president should reinforce the need to strengthen implementations of social distancing recommendations and the use of masks to mitigate the spread of coronavirus," he added.
Bolsonaro has repeatedly defied local guidelines to wear a mask in public, even after a judge ordered him to do so in late June. Bolsonaro has also railed against social distancing rules supported by the World Health Organization.
The US embassy in Brasilia said via Twitter on Monday that the ambassador had lunch on July 4 with Bolsonaro, five ministers and the president's son, Congressman Eduardo Bolsonaro. The ambassador had no symptoms, but would undergo testing and is "taking precautions," the embassy said.