Vibrio vulnificus epidemiology and risk factors for mortality in the United States, 2000-2022.

Background: Vibrio vulnificus is a foodborne and waterborne pathogen causing substantial morbidity and mortality; however, its epidemiology remains poorly understood. To inform prevention and control efforts, we characterized U.S. V. vulnificus epidemiology and identified risk factors for mortality.

Methods: For all culture-confirmed V. vulnificus cases reported to the Cholera and Other Vibrio Illness Surveillance (COVIS) system from 2000 to 2022, patient characteristics and medical outcomes were described by foodborne vs. non-foodborne transmission routes. Risk factors for mortality were identified using multivariate logistic regression.

Results: Two thousand nine hundred and eighty-nine V. vulnificus cases were reported from 2000 to 2022, including 656 (22%) foodborne and 1,619 (54%) non-foodborne cases. Five-year case total increased 70% from 2000-2004 (n = 487) to 2018-2022 (n = 827). Most patients were male, older and White, with reported underlying health conditions; 2,493 (83%) patients were hospitalized and 692 (23%) died. Number of deaths (260 vs. 200) and fatality rate (40% vs. 12%) were higher among foodborne vs. non-foodborne cases. Mortality was associated with history of liver disease/alcoholism (odds ratio (OR) = 6.5, p < 0.001), age 45-59 (OR = 11.3, p = 0.001), foodborne transmission (OR = 1.3, p = 0.006), and Black (OR = 1.8, p = 0.03) or Asian (OR = 2.5, p = 0.009) race. Antibiotic use was protective (OR = 0.33, p = 0.001). Liver disease associated with diabetes had lower mortality than other forms of liver disease (interaction OR = 0.5, p = 0.04).

Conclusions: V. vulnificus infections confer a substantial and increasing public health burden in the United States. Non-foodborne transmission caused 2.5 times more cases, and foodborne transmission caused 30% more deaths and had >3 times higher fatality rate. Identifying risk factors for mortality can inform public health and medical interventions.