None of them come close to Mr Levitinn’s streak, a combination, doctors say, of his physical and mental strength and the speed with which the medical establishment has developed protocols for long-term care for Covid.

“He had a long and difficult road,” wrote Dr. Abraham Sanders, one of his doctors at Weill Cornell, in an email. “He was a strong man and benefited from sophisticated medical care.”

Murad Albert Lewitinn was born on March 12, 1946 into a Jewish family in Cairo. (As a child, he anglicized his first name to Marco and later dropped the O.) His father, Albert Lewitinn, was a medical technician and his mother, Sarah (Amiga) Lewitinn, was a homemaker. He grew up speaking Arabic and later learned English, French and Spanish.

Egypt had a thriving Jewish community of 75,000, but after the Arab nationalist revolution in 1952 and the Suez Crisis in 1956, which pitted the country against Israel, France and Britain, they faced deteriorating conditions. The government took over the elderly Mr. Lewitinn’s business, and after a brief imprisonment, he and his family were expelled in 1958.

They settled in Baltimore, where Albert Lewitinn was hired by Johns Hopkins University to work on organ transplant technology.

As a young man, Marc lived in New York City and Los Angeles, where he briefly attended college, then in Paris, where he met Ondine Green, the sister of a childhood friend from Cairo. They married in 1968.