President Andrzej Duda of Poland Tests Positive for Coronavirus

BRUSSELS — President Andrzej Duda of Poland has tested positive for Covid-19 and will go into quarantine, his spokesman said on Saturday, adding to the list of global leaders who have been infected as coronavirus cases rise unabated in several world hot spots.

“The president is feeling well,” the spokesman, Blazej Spychalski, said of Mr. Duda. The head of the presidential office said that it would “probably compile a list of the president’s contacts,” adding that this was “a new situation.”

The country’s de facto leader, Jaroslaw Kaczynski, also went into self-isolation this week, after learning that he had been in contact with someone infected with the virus. A government spokesman said that Mr. Kaczynski, the 71-year-old leader of the governing Law and Justice Party, “feels well and will continue performing his duties from home.”

Poland, the Czech Republic and Bulgaria are experiencing among the most severe outbreaks in Europe. This second wave of infection has led Poland’s government to impose new restrictions on public life starting on Saturday and to convert the country’s national stadium in Warsaw into a temporary field hospital with room for 500 coronavirus patients.

Mr. Duda visited the stadium on Friday and met with site managers, an encounter that has now raised concerns that the construction will have to be halted. He also met Iga Swiatek, who this month became the first Polish female tennis player to win the French Open.

Although Mr. Duda wore a mask and gloves during his stadium visit, Mr. Kaczynski did not wear a mask while handing out an award at a ceremony last week, and briefly removed his mask while being sworn in as deputy prime minister on Oct. 6.

Other world leaders who have contracted the virus have taken casual approaches to masks or resisted them. President Trump, who throughout the pandemic has largely shunned the use of face masks and social distancing practices, removed his mask during a public appearance this month despite having fallen ill with the virus.

Prime Minister Boris Johnson of Britain, who in March boasted of shaking hands with “everyone” while visiting a hospital that was treating coronavirus patients, adopted a more somber approach after being hospitalized with the virus himself. President Jair Bolsonaro of Brazil continued to question the merits of lockdown measures even after contracting a mild case of the virus.

In Poland, which largely avoided the first wave of the pandemic by imposing an early lockdown in March, nearly a third of its approximately 215,000 total cases have emerged in the past week. The country, which Prime Minister Mateusz Morawiecki designated as a “red zone” at a news conference on Friday, has also had more than 4,000 recorded deaths from the virus.

There are concerns about how Poland’s underfunded health care system will cope with the growing number of virus patients. In addition to plans to turn the national stadium into a field hospital, the government said that temporary virus hospitals would be also built in major cities.

At the news conference, Mr. Morawiecki also announced new restrictions that came into effect on Saturday.

The government ordered all cafes, bars and restaurants to close, except for take out, and gyms and swimming pools were also shut. Residents must use face coverings outside their homes, and remote teaching will become a norm for older children in primary schools, as well as in high schools and at universities.

Young people up to 16 years old are not allowed outside from 8 a.m. to 4 p.m. without adult supervision under the new measures, and socializing in groups of more than five is forbidden. The government also asked that people over 70 stay home.

“We are far away from the comfort zone,” Adam Niedzielski, the health minister, said during the news conference.

Monika Pronczuk reported from Brussels, and Tess Felder from London. Anatol Magdziarz contributed reporting from Warsaw.