title: Differential and enhanced response to climate forcing in diarrheal disease due to rotavirus across a megacity of the developing world.
abstract: The role of climate forcing in the population dynamics of infectious diseases has typically been revealed via retrospective analyses of incidence records aggregated across space and, in particular, over whole cities. Here, we focus on the transmission dynamics of rotavirus, the main diarrheal disease in infants and young children, within the megacity of Dhaka, Bangladesh. We identify two zones, the densely urbanized core and the more rural periphery, that respond differentially to flooding. Moreover, disease seasonality differs substantially between these regions, spanning variation comparable to the variation from tropical to temperate regions. By combining process-based models with an extensive disease surveillance record, we show that the response to climate forcing is mainly seasonal in the core, where a more endemic transmission resulting from an asymptomatic reservoir facilitates the response to the monsoons. The force of infection in this monsoon peak can be an order of magnitude larger than the force of infection in the more epidemic periphery, which exhibits little or no postmonsoon outbreak in a pattern typical of nearby rural areas. A typically smaller peak during the monsoon season nevertheless shows sensitivity to interannual variability in flooding. High human density in the core is one explanation for enhanced transmission during troughs and an associated seasonal monsoon response in this diarrheal disease, which unlike cholera, has not been widely viewed as climate-sensitive. Spatial demographic, socioeconomic, and environmental heterogeneity can create reservoirs of infection and enhance the sensitivity of disease systems to climate forcing, especially in the populated cities of the developing world.
authors.affiliation: Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637;
authors.forename: Pamela P
authors.initials: PP
authors.lastname: Martinez
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109; Department of Mathematics, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Aaron A
authors.initials: AA
authors.lastname: King
authors.affiliation: International Centre for Diarrheal Disease Research, Dhaka 1000, Bangladesh;
authors.forename: Mohammad
authors.initials: M
authors.lastname: Yunus
authors.affiliation: International Centre for Diarrheal Disease Research, Dhaka 1000, Bangladesh;
authors.forename: A S G
authors.initials: AS
authors.lastname: Faruque
authors.affiliation: Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637; Santa Fe Institute, Santa Fe, NM 87501 pascualmm@uchicago.edu.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Pascual
mesh_terms: D001459:Bangladesh / Q000453:epidemiology; D002980:Climate; D003906:Developing Countries; D003967:Diarrhea / Q000453:epidemiology*; D055868:Floods; D006801:Humans; D012400:Rotavirus Infections / Q000453:epidemiology*; D012621:Seasons
keywords: diarrheal disease; epidemiological model; monsoon flooding; rotavirus transmission; urban health