A cross-sectional analysis of ITN and IRS coverage in Namibia in 2013

Sophie H Allcock,Elizabeth H Young,Manjinder S Sandhu

doi:10.1186/s12936-018-2417-z

Sophie H Allcock, Elizabeth H Young + Show 1 more

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https://doi.org/10.1186/s12936-018-2417-z

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Journal: Malaria journal	Publication Date: Jul 16, 2018
Citations: 5	License type: open-access

Affiliation: University of Cambridge, Wellcome Sanger Institute

Abstract

BackgroundAchieving vector control targets is a key step towards malaria elimination. Because of variations in reporting of progress towards vector control targets in 2013, the coverage of these vector control interventions in Namibia was assessed.MethodsData on 9846 households, representing 41,314 people, collected in the 2013 nationally-representative Namibia Demographic and Health Survey were used to explore the coverage of two vector control methods: indoor residual spraying (IRS) and insecticide-treated nets (ITNs). Regional data on Plasmodium falciparum parasite rate in those aged 2–10 years (PfPR2–10), obtained from the Malaria Atlas Project, were used to provide information on malaria transmission intensity. Poisson regression analyses were carried out exploring the relationship between household interventions and PfPR2–10, with fully adjusted models adjusting for wealth and residence type and accounting for regional and enumeration area clustering. Additionally, the coverage as a function of government intervention zones was explored and models were compared using log-likelihood ratio tests.ResultsIntervention coverage was greatest in the highest transmission areas (PfPR2–10 ≥ 5%), but was still below target levels of 95% coverage in these regions, with 27.6% of households covered by IRS, 32.3% with an ITN and 49.0% with at least one intervention (ITN and/or IRS). In fully adjusted models, PfPR2–10 ≥ 5% was strongly associated with IRS (RR 14.54; 95% CI 5.56–38.02; p < 0.001), ITN ownership (RR 5.70; 95% CI 2.84–11.45; p < 0.001) and ITN and/or IRS coverage (RR 5.32; 95% CI 3.09–9.16; p < 0.001).ConclusionsThe prevalence of IRS and ITN interventions in 2013 did not reflect the Namibian government intervention targets. As such, there is a need to include quantitative monitoring of such interventions to reliably inform intervention strategies for malaria elimination in Namibia.

Highlights

Achieving vector control targets is a key step towards malaria elimination
There were a total of 4763 urban and 5083 rural households, and 50.2% of households were in the highest transmission areas (PfPR2–10 ≥ 5%) (Table 1)
Low transmission occurred in Zambezi and Omaheke (PfPR2–10 1 to < 5%)

Summary

Introduction

Achieving vector control targets is a key step towards malaria elimination. Because of variations in reporting of progress towards vector control targets in 2013, the coverage of these vector control interventions in Namibia was assessed. Interventions for malaria control and elimination include indoor residual spraying (IRS), insecticidetreated nets (ITNs) and long-lasting insecticide-treated nets (LLINs). These are effective tools for reducing the adult mosquito population density and longevity, and are fundamental for interrupting transmission [2]. PfPR2–10, Plasmodium falciparum parasite rate in those aged 2–10 years; EA, enumeration area; MSP, Malaria Strategic Plan; IRS, indoor residual spraying; ITN, insecticide-treated net a n = 9842 the geographical distribution of malaria transmission intensity (Fig. 1a). In multivariable mixed effects analyses, regional PfPR2–10 was significantly positively associated with IRS, with households in the ≥ 5% category most likely to have been sprayed (RR 14.54; 95% CI 5.56–38.02) (Table 3). Sensitivity analyses indicated that this relationship was inconsistent across urban and rural areas (Additional file 1: Table S1)

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Conclusion