A medical worker tends to a patient in a hospital in Lombardy.

A total of 4,826 health care workers in Italy have been infected by the novel coronavirus, according to the latest information Sunday from Italy’s National Health Institute (ISS).

That means some 9% of those infected nationwide by Covid-19 are health care workers.

Italy’s National Federation of Surgeons and Dentists is publishing a record of doctors who have contracted and died of Covid-19 since the start of the outbreak. It lists 18 doctors who have passed away since March 11; of those, 15 are from Lombardy, the hardest-hit region and the epicenter of Italy’s outbreak.

It is unclear if each of the doctors listed was directly battling the coronavirus outbreak and treating the infected.

Among those doctors who have died is Marcello Natali, 57, who died on March 18, according to the federation website.

Natali, as reported by local media, had been a vocal critic of the initial Italian government response to the outbreak, and also sounded the alarm on the dearth of medical supplies.

Also among the doctors who have died is Francesco Foltrani, 67, who died on March 19. The federation says Foltrani had in-person contact with a local retirement home where many of the elderly residents were known to have contracted coronavirus.

By the numbers: There are approximately 53,578 confirmed coronavirus cases in Italy, according to the Johns Hopkins University & Medicine Coronavirus Resource Center.