NEW YORK — U.S. health officials are warning of an increase in rare bacterial illnesses than can lead to meningitis and possible death. The Centers for Disease Control and Prevention issued an alert to U.S. doctors on Thursday about an increase in cases of one type of invasive meningococcal disease, most of it due to a specific strain of bacteria. Last year, 422 cases of it were reported in the U.S.—the most in a year since 2014.