Efficacy, Safety and Cost of Insecticide Treated Wall Lining, Insecticide Treated Bed Nets and Indoor Wall Wash with Lime for Visceral Leishmaniasis Vector Control in the Indian Sub-continent: A Multi-country Cluster Randomized Controlled Trial.

Dinesh Mondal,Pradeep Das,Alexander Upfill-Brown,Debashis Ghosh,Axel Kroeger,Jyoti Priyanka,M Mamun Huda,Greg Matlashewski,Murari Lal Das,Rajib Chowdhury,Vijay Kumar,Alvaro Acosta-Serrano

doi:10.1371/journal.pntd.0004932

Abstract

BackgroundWe investigated the efficacy, safety and cost of lime wash of household walls plus treatment of sand fly breeding places with bleach (i.e. environmental management or EM), insecticide impregnated durable wall lining (DWL), and bed net impregnation with slow release insecticide (ITN) for sand fly control in the Indian sub-continent.MethodsThis multi-country cluster randomized controlled trial had 24 clusters in each three sites with eight clusters per high, medium or low sand fly density stratum. Every cluster included 45–50 households. Five households from each cluster were randomly selected for entomological measurements including sand fly density and mortality at one, three, nine and twelve months post intervention. Household interviews were conducted for socioeconomic information and intervention acceptability assessment. Cost for each intervention was calculated. There was a control group without intervention.FindingsSand fly mortality [mean and 95%CI] ranged from 84% (81%-87%) at one month to 74% (71%-78%) at 12 months for DWL, 75% (71%-79%) at one month to 49% (43%-55%) at twelve months for ITN, and 44% (34%-53%) at one month to 22% (14%-29%) at twelve months for EM. Adjusted intervention effect on sand fly density measured by incidence rate ratio ranged from 0.28 (0.23–0.34) at one month to 0.62 (0.51–0.75) at 12 months for DWL; 0.72 (0.62–0.85) at one month to 1.02 (0.86–1.22) at 12 months for ITN; and 0.89 (0.76–1.03) at one months to 1.49 (1.26–1.74) at 12 months for EM. Household acceptance of EM was 74% compared to 94% for both DWL and ITN. Operational cost per household in USD was about 5, 8, and 2 for EM, DWL and ITN, respectively. Minimal adverse reactions were reported for EM and ITN while 36% of households with DWL reported transient itching.InterpretationDWL is the most effective, durable and acceptable control method followed by ITN. The Visceral Leishmaniasis (VL) Elimination Program in the Indian sub-continent should consider DWL and ITN for sand fly control in addition to IRS.

Highlights

Visceral leishmaniasis (VL), known as kala-azar, is a neglected vector-borne disease caused by the protozoan parasite Leishmania donovani and is transmitted by the female Phlebotomus argentipes sand fly
Indoor residual spraying with insecticides (IRS) is the most effective method available for sand fly control
The efficacy of other methods of vector control remains poorly understood. These additional techniques need to be explored in order to complement IRS or replace it if it is unavailable. In this multi-country study we investigated the efficacy, safety and cost of lime wash of household walls plus treatment of sand fly breeding places with bleach (EM), insecticide impregnated durable wall lining (DWL), and bed net impregnation with slow release insecticide (ITN) for sand fly control in the Indian sub-continent

Summary

Introduction

Visceral leishmaniasis (VL), known as kala-azar, is a neglected vector-borne disease caused by the protozoan parasite Leishmania donovani and is transmitted by the female Phlebotomus argentipes sand fly. The poorest of the rural areas of Bangladesh, India, Nepal and East Africa are the victims of the disease which is fatal if not treated [1]. Bangladesh, India and Nepal contribute up to 60% of the VL burden in the world [2]. The Governments of Bangladesh, Indian and Nepal committed to eliminate VL as a public health problem with a target of less than 1 case per 10,000 people at upazila, district and block level in Bangladesh, Nepal and India respectively by 2017 [2,3]. Integrated vector management (IVM) is one of the strategies of the VL elimination program and is mostly depending on indoor residual spraying with insecticides (IRS). Safety and cost of lime wash of household walls plus treatment of sand fly breeding places with bleach (i.e. environmental management or EM), insecticide impregnated durable wall lining (DWL), and bed net impregnation with slow release insecticide (ITN) for sand fly control in the Indian sub-continent

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