To have any hope of avoiding that disaster in the U.S., the health care system needs to decentralize and make the community a focus of interventions on a par with patients, said Cereda, a graduate of the medical school at the University of Milan who has been in touch with colleagues in Italy. The coronavirus has now killed more people there (the toll passed 4,000 this week) than in China (3,255).

One such step reflects the finding that hospitals might be “the main” source of Covid-19 transmission, the Bergamo doctors warned. The related coronavirus illness MERS also has high transmission rates within hospitals, as did SARS during its 2003 epidemic.

Major hospitals such as Bergamo’s “are themselves becoming sources of [coronavirus] infection,” Cereda said, with Covid-19 patients indirectly transmitting infections to non-Covid-19 patients. Ambulances and infected personnel, especially those without symptoms, carry the contagion both to other patients and back into the community.

“All my friends in Italy tell me the same thing,” Cereda said. “[Covid-19] patients started arriving and the rate of infection in other patients soared. That is one thing that probably led to the current disaster.”