Risk factors for household vector abundance using indoor CDC light traps in a high malaria transmission area of Northern Zambia

Marisa A. Hast, Jennifer Claire Stevenson, Mbanga Muleba, Mike Chaponda, Jean Bertin Kabuya, Modest Mulenga, Justin T Lessler, Timothy M Shields, William J Moss, Douglas Norris

Research output: Contribution to journalArticle

Abstract

Malaria transmission is dependent on the density and distribution of mosquito vectors, but drivers of vector abundance have not been adequately studied across a range of transmission settings. To inform intervention strategies for high-burden areas, further investigation is needed to identify predictors of vector abundance. Active household (HH) surveillance was conducted in Nchelenge district, Luapula Province, northern Zambia, a high-transmission setting with limited impact ofmalaria control. Between April 2012 and July 2017,mosquitoeswere collected indoors during HH visits using CDC light traps. Demographic, environmental, and climatological correlates of vector abundance were identified using log-binomial regressionmodels with robust standard errors. The primarymalaria vectors in this setting were Anopheles funestus sensu stricto (s.s.) andAnopheles gambiae s.s. Anopheles funestus predominated inboth seasons, with a peak in the dry season. Anopheles gambiae peaked at lower numbers in the rainy season. Environmental, climatic, and demographic factors were correlated with HH vector abundance. Higher vector counts were found in rural areas with low population density and among HHs close to roads and small streams. Vector counts were lower with increasing elevation and slope. Anopheles funestus was negatively associated with rainfall at lags of 2-6weeks, and An. gambiae was positively associated with rainfall at lags of 3-10 weeks. Both vectors had varying relationships with temperature. These results suggest thatmalaria vector control in Nchelenge district should occur throughout the year, with an increased focus on dry-season transmission and rural areas.

Original languageEnglish (US)
Pages (from-to)126-136
Number of pages11
JournalAmerican Journal of Tropical Medicine and Hygiene
Volume101
Issue number1
DOIs
Publication statusPublished - Jan 1 2019

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ASJC Scopus subject areas

  • Parasitology
  • Infectious Diseases
  • Virology

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