title: Extreme precipitation events and increased risk of campylobacteriosis in Maryland, U.S.A.
abstract: Consumption of contaminated poultry, raw milk and water are significant risk factors for Campylobacter infection. Previous studies also have investigated the association between weather (temperature and precipitation) and increased risk of campylobacteriosis, but limited information exists regarding the impacts of extreme heat and precipitation events on campylobacteriosis risk, and how such risk may differentially impact coastal communities. We obtained Campylobacter case data 2002-2012; n=4804) from the Maryland Foodborne Diseases Active Surveillance Network (FoodNet). We identified extreme heat and extreme precipitation events during this time (2002-2012) using location and calendar day specific thresholds (95th percentile for extreme heat and 90th percentile for extreme precipitation) that were computed based on a 30-year baseline (1960-1989). We linked these datasets using GIS and used negative binomial generalized estimating equations adjusted for demographic confounders to calculate the association between exposure to extreme events and risk of campylobacteriosis in Maryland. We observed that a one-day increase in exposure to extreme precipitation events was associated with a 3% increase in risk of campylobacteriosis in coastal areas of Maryland (Incidence Rate Ratio (IRR): 1.03, 95% confidence interval (CI): 1.01, 1.05), but such an association was not observed in noncoastal areas. Furthermore, the risk associated with extreme precipitation events was considerably higher during La Niña periods (IRR: 1.09, 95% CI: 1.05, 1.13), while there was no evidence of elevated risk during El Niño or ENSO Neutral periods. Exposure to extreme heat events was not associated with an increased risk of campylobacteriosis, except during La Niña periods (IRR: 1.04, 95% CI: 1.01, 1.08). Extreme precipitation events could result in flooding within coastal areas that may bring water contaminated with bacterial pathogens (originating from sources such as septic systems, municipal wastewater treatment plants and concentrated animal feeding operations) into close proximity with individuals, where frequency of contact may be higher.
authors.affiliation: Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, United States.
authors.forename: Sutyajeet
authors.initials: S
authors.lastname: Soneja
authors.affiliation: Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, United States.
authors.forename: Chengsheng
authors.initials: C
authors.lastname: Jiang
authors.affiliation: Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, United States.
authors.forename: Crystal
authors.initials: C
authors.lastname: Romeo Upperman
authors.affiliation: Earth System Science Interdisciplinary Center, College of Computer, Mathematical and Natural Sciences, University of Maryland, College Park, MD, United States.
authors.forename: Raghu
authors.initials: R
authors.lastname: Murtugudde
authors.affiliation: Prevention and Health Promotion Administration, Maryland Department of Health and Mental Hygiene, Baltimore, MD, United States.
authors.forename: Clifford
authors.initials: C
authors.lastname: S Mitchell
authors.affiliation: Prevention and Health Promotion Administration, Maryland Department of Health and Mental Hygiene, Baltimore, MD, United States.
authors.forename: David
authors.initials: D
authors.lastname: Blythe
authors.affiliation: Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, United States.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Sapkota
authors.affiliation: Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, United States. Electronic address: amirsap@umd.edu.
authors.forename: Amir
authors.initials: A
authors.lastname: Sapkota
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002167:Campylobacter / Q000302:isolation & purification*; D002169:Campylobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D059000:El Nino-Southern Oscillation; D055874:Extreme Heat; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D011891:Rain; D012307:Risk Factors; D055815:Young Adult
keywords: Campylobacteriosis; Climate change; Coastal vulnerability; El Niño; La Niña