Characterizing microclimate in urban malaria transmission settings: a case study from Chennai, India

Malaria Journal

Research

Krijn P Paaijmans¹  Lauren J Cator²  Andrew F Read²  Matthew B Thomas²  Manu T Mathai³  Shalu Thomas⁴  Alex Eapen⁴  Sangamithra Ravishankaran⁴  Johnson A Justin⁴ 

[1] Department of Entomology, Center for Infectious Disease Dynamics and Department of Entomology, Merkle Lab, The Pennsylvania State University, 16802, University Park, PA, USA;Department of Entomology, Center for Infectious Disease Dynamics and Department of Entomology, Merkle Lab, The Pennsylvania State University, 16802, University Park, PA, USA;Center for Infectious Disease Dynamics, The Pennsylvania State University, 16802, University Park, PA, USA;Department of Zoology, Madras Christian College, 600 059, Tambaram, Chennai, India;National Institute of Malaria Research (ICMR), IDVC Field Unit, NIE Campus, 2nd Main Road, TNHB, Ayapakkam, 600 077, Chennai, India;

关键词: Temperature;    Extrinsic incubation period;    Anopheles stephensi;    Urban malaria;   

DOI  :  10.1186/1475-2875-12-84

 received in 2012-12-24, accepted in 2013-02-26,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundEnvironmental temperature is an important driver of malaria transmission dynamics. Both the parasite and vector are sensitive to mean ambient temperatures and daily temperature variation. To understand transmission ecology, therefore, it is important to determine the range of microclimatic temperatures experienced by malaria vectors in the field.MethodsA pilot study was conducted in the Indian city of Chennai to determine the temperature variation in urban microclimates and characterize the thermal ecology of the local transmission setting. Temperatures were measured in a range of probable indoor and outdoor resting habitats of Anopheles stephensi in two urban slum malaria sites. Mean temperatures and daily temperature fluctuations in local transmission sites were compared with standard temperature measures from the local weather station. The biological implications of the different temperatures were explored using temperature-dependent parasite development models to provide estimates of the extrinsic incubation period (EIP) of Plasmodium vivax and Plasmodium falciparum.ResultsMean daily temperatures within the urban transmission sites were generally warmer than those recorded at the local weather station. The main reason was that night-time temperatures were higher (and hence diurnal temperature ranges smaller) in the urban settings. Mean temperatures and temperature variation also differed between specific resting sites within the transmission environments. Most differences were of the order of 1-3°C but were sufficient to lead to important variation in predicted EIPs and hence, variation in estimates of transmission intensity.ConclusionsStandard estimates of environmental temperature derived from local weather stations do not necessarily provide realistic measures of temperatures within actual transmission environments. Even the small differences in mean temperatures or diurnal temperature ranges reported in this study can lead to large variations in key mosquito and/or parasite life history traits that determine transmission intensity. Greater effort should be directed at quantifying adult mosquito resting behaviour and determining the temperatures actually experienced by mosquitoes and parasites in local transmission environments. In the absence of such highly resolved data, the approach used in the current study provides a framework for improved thermal characterization of transmission settings.

【 授权许可】

Unknown   
© Cator et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.