title: Recreational swimmers' exposure to Vibrio vulnificus and Vibrio parahaemolyticus in the Chesapeake Bay, Maryland, USA.
abstract: Vibrio vulnificus and Vibrio parahaemolyticus are ubiquitous in the marine-estuarine environment, but the magnitude of human non-ingestion exposure to these waterborne pathogens is largely unknown. We evaluated the magnitude of dermal exposure to V. vulnificus and V. parahaemolyticus among swimmers recreating in Vibrio-populated waters by conducting swim studies at four swimming locations in the Chesapeake Bay in 2009 and 2011. Volunteers (n=31) swam for set time periods, and surface water (n=25) and handwash (n=250) samples were collected. Samples were analyzed for Vibrio concentrations using quantitative PCR. Linear and logistic regressions were used to evaluate factors associated with recreational exposures. Mean surface water V. vulnificus and V. parahaemolyticus concentrations were 1128CFUmL(-1) (95% confidence interval (CI): 665.6, 1591.4) and 18CFUmL(-1) (95% CI: 9.8, 26.1), respectively, across all sampling locations. Mean Vibrio concentrations in handwash samples (V. vulnificus, 180CFUcm(-2) (95% CI: 136.6, 222.5); V. parahaemolyticus, 3CFUcm(-2) (95% CI: 2.4, 3.7)) were significantly associated with Vibrio concentrations in surface water (V. vulnificus, p<0.01; V. parahaemolyticus, p<0.01), but not with salinity or temperature (V. vulnificus, p=0.52, p=0.17; V. parahaemolyticus, p=0.82, p=0.06). Handwashing reduced V. vulnificus and V. parahaemolyticus on subjects' hands by approximately one log (93.9%, 89.4%, respectively). It can be concluded that when Chesapeake Bay surface waters are characterized by elevated concentrations of Vibrio, swimmers and individuals working in those waters could experience significant dermal exposures to V. vulnificus and V. parahaemolyticus, increasing their risk of infection.
authors.affiliation: University of Maryland, Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, MD 21601, USA; University of Maryland, School of Public Health, Maryland Institute for Applied Environmental Health, 2234P SPH Building, College Park, MD 20742, USA. Electronic address: krististevensshaw@gmail.com.
authors.forename: Kristi S
authors.initials: KS
authors.lastname: Shaw
authors.affiliation: University of Maryland, School of Public Health, Maryland Institute for Applied Environmental Health, 2234P SPH Building, College Park, MD 20742, USA.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Sapkota
authors.affiliation: National Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Cooperative Oxford Laboratory (COL), 904 S. Morris Street, Oxford, MD 21654, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Jacobs
authors.affiliation: University of Maryland, School of Public Health, Department of Epidemiology and Biostatistics, 2234H SPH Building, College Park, MD 20742, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: He
authors.affiliation: University of Maryland, Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, MD 21601, USA; Oregon State University, College of Earth, Ocean, and Atmospheric Science, 104 CEOAS Administration Building, Corvallis, OR, USA.
authors.forename: Byron C
authors.initials: BC
authors.lastname: Crump
mesh_terms: D061006:Bays; D004781:Environmental Exposure; D006801:Humans; D008396:Maryland; D054712:Salinity; D013550:Swimming; D013696:Temperature; D014736:Vibrio parahaemolyticus / Q000302:isolation & purification*; D041261:Vibrio vulnificus / Q000302:isolation & purification*; D014871:Water Microbiology
keywords: Chesapeake Bay; Exposure assessment; Recreational exposure; Vibrio parahaemolyticus; Vibrio vulnificus; Waterborne illness