LONDON — Even as governments around the world struggle to contain the coronavirus pandemic, many officials are themselves falling victim to the pathogen, undermining global efforts to address the crisis.

Prime Minister Justin Trudeau of Canada put himself in isolation after his wife tested positive, and a number of other senior officials from Britain to Iran to Australia were confirmed to be infected. President Jair Bolsonaro of Brazil said on Friday that he tested negative, after one of his aides tested positive.

There is, though, rising concern that President Donald Trump and members of his staff and cabinet might have been exposed in meetings with different officials from overseas, including with Mr. Bolsonaro’s aide.

In a closely connected political world where officials crisscross the globe as they take part in frequent meetings with heads of state and other policymakers, the cases vividly illustrate how no one is immune from a virus that does not distinguish between the powerful and everyone else.