Abstract
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, https://pactr.samrc.ac.za/.
Highlights
Current standard interventions are not universally sufficient for malaria elimination
In the context of high insecticide-treated bed net use, neither community-based house improvement (HI), larval source management (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
During five rounds in the baseline period (April 2015 through April 2016) and 12 rounds in the trial period (May 2016 through May 2018), 1380 and 3240 households, respectively, were selected for epidemiological surveys; in the trial period, some households were selected multiple times in different rounds. 1072 and 1844 unique household visits during baseline and trial periods, respectively, were included in the analysis presented here, including households that were replaced by the nearest neighbour when the selected household was absent. 42 visits and 118 visits ended when the head of household did not consent, and a further 266 visits and 1098 visits were to households without at least one child aged 6–59 months or woman aged 15–49 years
Summary
Current standard interventions are not universally sufficient for malaria elimination. There are multiple, overlapping challenges limiting the ability of the current malaria interventions to continue reducing malaria burden at the rate observed from 2000 to 2015, including insecticide resistance [4], drug resistance [5], barriers to achieving target access, use, acceptability and sustainability [6], and residual malaria transmission [7]. Due to these well documented challenges, the need for additional malaria interventions is widely recognized [8]. Two vector control interventions that could provide additional protection from malaria when integrated into standard national control programmes are house improvement (HI) and larval source management (LSM) [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
