Pertussis in Florida, 2000–2006: Trends in a Historically Low-Incidence State

Abstract

Objective. Florida, the fourth most populous state in the nation, has had historically low incidence rates of pertussis, the only vaccine-preventable disease with increasing numbers of reported cases. We compared the epidemiology and incidence rates of pertussis in Florida with other states and the United States. Methods. We used Florida and federal surveillance data from 2000 through 2006. Results. Reported incidence of pertussis in Florida, numbers of cases, and proportions of adolescents and adults all increased during the seven-year study period. Florida incidence rates increased from 0.44 to 1.28, but the state's incidence was always ranked 45th or lower among the states. Reported pertussis cases and those among adolescents and adults in Florida increased during the study period. Ten counties, containing 60% of Florida's population, reported two-thirds of the state's cases. Conclusions. Pertussis reported from Florida mirrored national trends with increasing incidence, numbers of cases, and proportions of adolescent and adult cases. Despite the increases, Florida maintained its historic pattern of pertussis incidence rates that are consistently lower than national figu es. Limited laboratory diagnostics and a focus on the pediatric population likely contributed to the lower rates of pertussis in Florida. More emphasis on surveillance of adolescent and adult cases is needed.