A rare bacterial disease linked to rats — and normally only seen in animals — has killed one person in the Bronx and left two others fighting for their lives, city officials reported Tuesday. The three cases of leptospirosis were identified within a one-block radius of the Concourse section of the borough over the past two months, the Health Department said. “Human leptospirosis cases are very rare in New York City,” explained Demetre Daskalakis, acting deputy commissioner of the Health Department. “This is the first time a cluster of cases has been identified,” he said. “All three cases had severe...