Temporal and micro-spatial heterogeneity in the distribution of Anopheles vectors of malaria along the Kenyan coast

Martin Walker, Peter Winskill, María Gloria Basáñez, Joseph M. Mwangangi, Charles Mbogo, John C. Beier, Janet T. Midega

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Background: The distribution of anopheline mosquitoes is determined by temporally dynamic environmental and human-associated variables, operating over a range of spatial scales. Macro-spatial short-term trends are driven predominantly by prior (lagged) seasonal changes in climate, which regulate the abundance of suitable aquatic larval habitats. Micro-spatial distribution is determined by the location of these habitats, proximity and abundance of available human bloodmeals and prevailing micro-climatic conditions. The challenge of analysing - in a single coherent statistical framework - the lagged and distributed effect of seasonal climate changes simultaneously with the effects of an underlying hierarchy of spatial factors has hitherto not been addressed. Methods. Data on Anopheles gambiae sensu stricto and A. funestus collected from households in Kilifi district, Kenya, were analysed using polynomial distributed lag generalized linear mixed models (PDL GLMMs). Results: Anopheline density was positively and significantly associated with amount of rainfall between 4 to 47 days, negatively and significantly associated with maximum daily temperature between 5 and 35 days, and positively and significantly associated with maximum daily temperature between 29 and 48 days in the past (depending on Anopheles species). Multiple-occupancy households harboured greater mosquito numbers than single-occupancy households. A significant degree of mosquito clustering within households was identified. Conclusions: The PDL GLMMs developed here represent a generalizable framework for analysing hierarchically-structured data in combination with explanatory variables which elicit lagged effects. The framework is a valuable tool for facilitating detailed understanding of determinants of the spatio-temporal distribution of Anopheles. Such understanding facilitates delivery of targeted, cost-effective and, in certain circumstances, preventative antivectorial interventions against malaria.

Original languageEnglish (US)
Article number311
JournalParasites and Vectors
Volume6
Issue number1
DOIs
StatePublished - Oct 30 2013

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Keywords

  • Anopheles funestus
  • Anopheles gambiae
  • Household occupancy
  • Kenya
  • Kilifi
  • Larval habitats
  • Malaria
  • Mosquito density
  • Polynomial distributed lag generalized linear mixed models
  • Rainfall
  • Temperature

ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases

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