Mexico’s president Andrés Manuel López Obrador, who has refused to wear a face mask, has tested positive for coronavirus days after dining with some of the nation’s leading industrialists.

“I am sorry to inform you that I have caught Covid-19. The symptoms are light but I’m having medical treatment. As ever, I’m optimistic. We’ll all get through this,” he wrote on Twitter on Sunday.

Mr López Obrador, 67, has been criticised for playing down the severity of the pandemic in Latin America’s second-biggest economy. He has continued to hold meetings across the country despite record deaths and infections in recent days.

Hospitals in Mexico City are almost full and many infected people have struggled to obtain access to oxygen tanks.

The Mexican leader follows other Covid-19 sceptics, such as Jair Bolsonaro of Brazil and Donald Trump in the US, in contracting the virus. At a news conference last year, Mr López Obrador displayed an amulet that he said protected him from the pandemic.

He said he would still hold a scheduled call with Vladimir Putin on Monday morning to discuss procuring Russia’s Sputnik V vaccine and bilateral ties.

The Mexican president said he intended to continue following public affairs from the National Palace, but that Olga Sánchez Cordero, the interior minister, would replace him at his daily morning news conference.

Mr López Obrador, who suffered a heart attack in 2013 and suffers from hypertension, has repeatedly sent an upbeat message that Mexico was coping well with the pandemic and has refused to enforce lockdown measures, despite more than 1.7m confirmed cases and almost 150,000 deaths.

Mexico’s low testing rate and high excess deaths point to a far bleaker picture. Its rolling seven-day average of new deaths, at 0.962 per 100,000, is higher than that of the US, with 0.935, and Brazil, at 0.474.

On Friday night, Mr López Obrador spoke by telephone with US president Joe Biden and posted a photograph to Twitter of himself around a table with Marcelo Ebrard, foreign minister, and former cabinet chief Alfonso Romo. Hugo López-Gatell, the country’s coronavirus tsar, attended the president’s daily morning news conference on Friday.

On López Obrador also dined on Friday with eight senior business leaders, as well as Mr Romo, his economy minister Tatiana Clouthier and Mr Ebrard in Monterrey, the country’s business capital.

A person close to the business leaders said none had displayed Covid symptoms and they were taking all precautions.

The president, who travels on commercial airlines, spent the weekend touring the states of Nuevo León and San Luis Potosí, where he inaugurated National Guard installations and supervised welfare projects.

José Luis Alomía, Mexico’s director-general of epidemiology, told a daily Covid-19 news conference that “fortunately [Mr López Obrador] is stable, his signs and symptoms are light, he is at home” under the care of a multidisciplinary medical team led by Jorge Alcocer, the health minister.

Contact tracing of people with whom the president had been in contact was under way, he added. This month, Jesús Ramírez, the president’s press chief, tested positive for the virus.