Canada is among numerous wealthy nations, including the United States and United Kingdom, that are aggressively recruiting medical workers from the developing world to replenish a health care work force drastically depleted by the Covid-19 pandemic. The urgency and strong pull from high-income nations — including countries like Germany and Finland, which had not previously recruited health workers from abroad — has upended migration patterns and raised new questions about the ethics of recruitment from countries with weak health systems during a pandemic.

“We have absolutely seen an increase in international migration,” said Howard Catton, the chief executive of the International Council of Nurses. But, he added, “The high, high risk is that you are recruiting nurses from countries that can least afford to lose their nurses.”

About 1,000 nurses are arriving in the United States each month from African nations, the Philippines and the Caribbean, said Sinead Carbery, president of O’Grady Peyton International, an international recruiting firm. While the United States has long drawn nurses from abroad, she said demand from American health care facilities is the highest she’s seen in three decades. There are an estimated 10,000 foreign nurses with U.S. job offers on waiting lists for interviews at American embassies around the world for the required visas.