title: Impact of El Niño Southern Oscillation on infectious disease hospitalization risk in the United States.
abstract: Although the global climate is changing at an unprecedented rate, links between weather and infectious disease have received little attention in high income countries. The "El Niño Southern Oscillation" (ENSO) occurs irregularly and is associated with changing temperature and precipitation patterns. We studied the impact of ENSO on infectious diseases in four census regions in the United States. We evaluated infectious diseases requiring hospitalization using the US National Hospital Discharge Survey (1970-2010) and five disease groupings that may undergo epidemiological shifts with changing climate: (i) vector-borne diseases, (ii) pneumonia and influenza, (iii) enteric disease, (iv) zoonotic bacterial disease, and (v) fungal disease. ENSO exposure was based on the Multivariate ENSO Index. Distributed lag models, with adjustment for seasonal oscillation and long-term trends, were used to evaluate the impact of ENSO on disease incidence over lags of up to 12 mo. ENSO was associated more with vector-borne disease [relative risk (RR) 2.96, 95% confidence interval (CI) 1.03-8.48] and less with enteric disease (0.73, 95% CI 0.62-0.87) in the Western region; the increase in vector-borne disease was attributable to increased risk of rickettsioses and tick-borne infectious diseases. By contrast, ENSO was associated with more enteric disease in non-Western regions (RR 1.12, 95% CI 1.02-1.15). The periodic nature of ENSO may make it a useful natural experiment for evaluation of the impact of climatic shifts on infectious disease risk. The impact of ENSO suggests that warmer temperatures and extreme variation in precipitation events influence risks of vector-borne and enteric disease in the United States.
authors: Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada; david.fisman@gmail.com.|Division of Infectious Diseases, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.
authors: David N
authors: DN
authors: Fisman
authors: Prevention Policy Modeling Laboratory, Harvard T. H. Chan School of Public Health, Boston, MA 02115.
authors: Ashleigh R
authors: AR
authors: Tuite
authors: Division of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada.|Public Health Ontario, Toronto, ON M5G 1V2, Canada.
authors: Kevin A
authors: KA
authors: Brown
mesh_terms: D000818:Animals; D002980:Climate; D057231:Climate Change; D003141:Communicable Diseases / Q000453:epidemiology*; D003428:Cross Infection; D004196:Disease Outbreaks; D004463:Ecology; D059000:El Nino-Southern Oscillation; D005843:Geography; D006760:Hospitalization; D006801:Humans; D007251:Influenza, Human / Q000453:epidemiology; D033183:Interdisciplinary Communication; D007410:Intestinal Diseases / Q000453:epidemiology; D015999:Multivariate Analysis; D009181:Mycoses / Q000453:epidemiology; D017711:Nonlinear Dynamics; D010351:Patient Discharge; D011014:Pneumonia / Q000453:epidemiology; D062486:Public Health Surveillance; D012282:Rickettsia Infections / Q000453:epidemiology; D012306:Risk; D013696:Temperature; D013987:Ticks; D014481:United States; D014887:Weather; D015047:Zoonoses / Q000453:epidemiology
keywords: El Nino Southern Oscillation; climate change; distributed lag models; epidemiology; infection