So many new doctors left Poland for better-paying jobs in Europe’s west that when Łukasz Rotnicki decided to stay behind he often found himself working 36-hour shifts, sleeping on the brown pullout sofa of a small-town hospital with too few staff. That was before Covid-19. On a recent Monday, the 36-year-old surgeon was on his 74th consecutive hour of treating coronavirus patients, broken by only a few short naps.

At the same hospital, a local nurse had recently been hospitalized, feverish and short of breath. Yet the staffing crunch was so dire that she kept working in the very Covid-19 ward where she was meant to recover, feeding the sick and turning them onto their stomachs before returning to her own bed in the same room.

Europe’s Covid-19 crisis is moving eastward, from the wealthiest and best-prepared countries on the continent into the poorer states that have exported doctors for decades. Now, as Covid-19 cases soar, the bill from that long exodus is coming due.

With 238 physicians per 100,000 people, Poland has the lowest such ratio in the European Union, nearly half the level of Germany, whose relative success in handling the virus owes much to its foreign staff. The average age of Polish nurses is 53, just seven years short of retirement.