The effect of community-driven larval source management and house improvement on malaria transmission when added to the standard malaria control strategies in Malawi: a cluster-randomized controlled trial.

Robert S McCann, Alinune N Kabaghe, Paula Moraga, Steven Gowelo, Monicah M Mburu, Tinashe Tizifa, Michael G Chipeta, William Nkhono, Aurelio Di Pasquale, Nicolas Maire, Lucinda Manda-Taylor, Themba Mzilahowa, Henk van den Berg, Peter J Diggle, Dianne J Terlouw, Willem Takken, Michèle van Vugt, Kamija S Phiri

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21 Scopus citations


BackgroundCurrent standard interventions are not universally sufficient for malaria elimination. The effects of community-based house improvement (HI) and larval source management (LSM) as supplementary interventions to the Malawi National Malaria Control Programme (NMCP) interventions were assessed in the context of an intensive community engagement programme.MethodsThe study was a two-by-two factorial, cluster-randomized controlled trial in Malawi. Village clusters were randomly assigned to four arms: a control arm; HI; LSM; and HI + LSM. Malawi NMCP interventions and community engagement were used in all arms. Household-level, cross-sectional surveys were conducted on a rolling, 2-monthly basis to measure parasitological and entomological outcomes over 3 years, beginning with one baseline year. The primary outcome was the entomological inoculation rate (EIR). Secondary outcomes included mosquito density, Plasmodium falciparum prevalence, and haemoglobin levels. All outcomes were assessed based on intention to treat, and comparisons between trial arms were conducted at both cluster and household level.ResultsEighteen clusters derived from 53 villages with 4558 households and 20,013 people were randomly assigned to the four trial arms. The mean nightly EIR fell from 0.010 infectious bites per person (95% CI 0.006-0.015) in the baseline year to 0.001 (0.000, 0.003) in the last year of the trial. Over the full trial period, the EIR did not differ between the four trial arms (p = 0.33). Similar results were observed for the other outcomes: mosquito density and P. falciparum prevalence decreased over 3 years of sampling, while haemoglobin levels increased; and there were minimal differences between the trial arms during the trial period.ConclusionsIn the context of high insecticide-treated bed net use, neither community-based HI, LSM, nor HI + LSM contributed to further reductions in malaria transmission or prevalence beyond the reductions observed over two years across all four trial arms. This was the first trial, as far as the authors are aware, to test the potential complementary impact of LSM and/or HI beyond levels achieved by standard interventions. The unexpectedly low EIR values following intervention implementation indicated a promising reduction in malaria transmission for the area, but also limited the usefulness of this outcome for measuring differences in malaria transmission among the trial arms. Trial registration PACTR, PACTR201604001501493, Registered 3 March 2016, .
Original languageEnglish (US)
JournalMalaria Journal
Issue number1
StatePublished - May 23 2021

Bibliographical note

KAUST Repository Item: Exported on 2021-05-27
Acknowledgements: We thank African Parks, The Hunger Project, the Malawi National Malaria Control Programme and the Chikwawa District Health Office for their signifcant and practical contributions in facilitating the study. We are grateful to the entire Majete Malaria Project team for their tireless eforts in carrying out the study. The population of the study area is thanked for their partnership in the project and cooperation with the study. We also thank: Alexandra Hiscox foradvice on mosquito sampling and study design; Jeroen Spitzen for logistical
assistance; Prosper Chaki for his valuable advice on LSM implementation; Tumaini Malenga and Marrit van den Berg for collaboration on socio-behavioral aspects of the study; and Martin Donnelly, Karl Seydel, and their respective laboratory teams for assistance in molecular identifcation of malaria parasites and anopheline mosquitoes.

ASJC Scopus subject areas

  • Infectious Diseases
  • Parasitology


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