Trends in Vibriosis Transmission among the Top Four Vibrio Species, United States, 1988-2012

Background Vibrio infection (vibriosis) results from consuming contaminated seafood or exposing skin directly to marine waters or raw seafood. The Centers for Disease Control and Prevention (CDC) estimates that 80,000 illnesses occur each year in the United States. Four species, V. parahaemolyticus, V. vulnificus, V. alginolyticus, and V. cholerae (excluding toxigenic O1 and O139), are responsible for most cases. Understanding foodborne and non-foodborne transmission routes is important for describing epidemiological trends and for directing prevention efforts. Methods Demographic, clinical, and epidemiological data for cases reported between 1988 and 2012 were extracted from CDC’s Cholera and Other Vibrio Illness Surveillance System (COVIS). Outcomes and seasonal trends were described by species and transmission route. Results A total of 10,173 domestically acquired, non-toxigenic cases of vibriosis were reported, including 4,224 (41.5%) V. parahaemolyticus cases, 1,998 (19.6%) V. vulnificus cases, 1,267 (12.5%) V. alginolyticus cases, and 963 (9.5%) V. cholerae cases. There were 4,026 hospitalizations and 795 deaths reported. When categorized by transmission route, 5,775 (56.8%) cases were foodborne and 3,317 (32.6%) were non-foodborne.. Most (52.4%) cases occurred during the summer months with peaks in July and August. Only 140 cases were reported from eight states in 1988 compared to 907 cases reported by 42 states in 2012. The overall crude incidence in 2011 was 0.26 cases per 100,000 population. Discussion The number of reported cases of vibriosis has been increasing steadily since 1988. Increased prevention efforts, including safer seafood products and consumer education, are needed.These efforts should focus on specific populations and transmission routes for each of the top four species that cause most vibriosis cases in the United States