title: A systematic review and meta-analysis of ambient temperature and diarrhoeal diseases.
abstract: BACKGROUND
  Global climate change is expected to increase the risk of diarrhoeal diseases, a leading cause of childhood mortality. However, there is considerable uncertainty about the magnitude of these effects and which populations bear the greatest risks.
  
  
  METHODS
  We conducted a systematic review using defined search terms across four major databases and, additionally, examined the references of 54 review articles captured by the search. We evaluated sources of heterogeneity by pathogen taxon, exposure measure, study quality, country income level and regional climate, and estimated pooled effect estimates for the subgroups identified in the heterogeneity analysis, using meta-analysis methods.
  
  
  RESULTS
  We identified 26 studies with 49 estimates. Pathogen taxa were a source of heterogeneity. There was a positive association between ambient temperature and all-cause diarrhoea (incidence rate ratio (IRR) 1.07; 95% confidence interval (CI) 1.03, 1.10) and bacterial diarrhoea (IRR 1.07; 95% CI 1.04, 1.10), but not viral diarrhoea (IRR 0.96; 95% CI 0.82, 1.11). These associations were observed in low-, middle- and high-income countries. Only one study of protozoan diarrhoea was identified.
  
  
  CONCLUSIONS
  Changes in temperature due to global climate change can and may already be affecting diarrhoeal disease incidence. The vulnerability of populations may depend, in part, on local pathogen distribution. However, evidence of publication bias and the uneven geographical distribution of studies limit the precision and generalizability of the pooled estimates.
authors.affiliation: Department of Environmental and Occupational Health, University of Colorado, Aurora, CO, USA, elizabeth.carlton@ucdenver.edu.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Carlton
authors.affiliation: Department of Environmental and Occupational Health, University of Colorado, Aurora, CO, USA.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Woster
authors.affiliation: Department of Biostatistics, University of Colorado, Aurora, CO, USA and.
authors.forename: Peter
authors.initials: P
authors.lastname: DeWitt
authors.affiliation: Department of Environmental Health, Emory University, Atlanta, GA, USA.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Goldstein
authors.affiliation: Department of Environmental Health, Emory University, Atlanta, GA, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Levy
mesh_terms: D057231:Climate Change; D003967:Diarrhea / Q000453:epidemiology*; D014943:Global Health; D006801:Humans; D015994:Incidence; D013696:Temperature
keywords: Ambient temperature; climate change; diarrhoea; vulnerability; weather