Manny Maceda, the leader of Bain & Co., lost sleep for a month after the coronavirus outbreak forced the big management consultancy and countless clients to shutter offices globally. “I worried that this pandemic might have a negative impact on our people and our business,’’ recalls Mr. Maceda, who rose to world-wide managing partner from summer intern. The 57-year-old consultant reached out to John Donahoe, a close confidant, because he had commanded Bain during a prior downturn.