Insecticide spraying reduces prevalence of trachoma

ARTICLE IN PRESS Evidence-Based Healthcare & Public Health (2004) 8, 284–285

www.elsevier.com/locate/ebhph

EVIDENCE-BASED PUBLIC HEALTH

Insecticide spraying reduces prevalence of trachoma$

KEYWORDS Trachoma; Musca sorbens; Insecticides; Flies; Latrines; Randomised controlled trial

Summary Question Does insecticide spraying or latrine provision reduce eye contact with flies (Musca sorbens) and reduce trachoma? Study Design

Cluster-randomised controlled trial.

Main results Number of Musca sorbens flies caught from children’s eyes. At 6 months follow-up, insecticide spraying and latrine provision reduced the number of flies caught compared with control (reduction in number of flies caught: insecticide spraying 88%, 95% CI 44 to 100; latrine provision 30%, 95% CI 7 to 52). Prevalence of trachoma. Baseline prevalence of trachoma was 6%. Insecticide spraying reduced prevalence of trachoma compared with control (mean reduction in prevalence: 56%, 95% CI 19 to 93). Latrine provision did not significantly reduce prevalence of trachoma (mean reduction in prevalence: 30%, 95% CI -81 to +22). Authors’ conclusions Insecticide spraying reduces the number of flies on children’s eyes and lowers prevalence of trachoma, however long-term use would lead to insecticide resistance. r 2004 Elsevier Ltd. All rights reserved.

Study Parameters Question Does insecticide spraying or latrine provision reduce eye contact with flies (Musca sorbens) and reduce trachoma? Study design Cluster-randomised controlled trial. Setting North Banks and Central River Divisions of The Gambia; September 1999-September 2001.

$ Abstracted from: Emerson PM, Lindsay SW, Alexander N et al. Role of flies and provision of latrines in trachoma control: clusterrandomised controlled trial. Lancet 2004; 363: 1093–1098.

1744-2249/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ehbc.2004.08.026

ARTICLE IN PRESS EVIDENCE-BASED PUBLIC HEALTH

285

Participants 21 clusters totaling 7080 people. Each cluster consisted of one or more closely neighbouring rural communities. Intervention Clusters were split into three groups. One group received non-ventilated household pit latrines, another underwent fly control for six months by spraying with permethrin, the final group received no intervention. Main Outcomes Fly eye contact: monitored once every two weeks by use of eight 15-minute hand-net catches from the faces of children younger than five years.Prevalence of active trachoma: all participants were screened for trachoma at baseline and after 6 months with the WHO simplified screen. Notes There was complete follow-up of 6087 of 7080 (86%) participants. Sources of funding: UK Government Department for International Development; Edna McConnell Clark Foundation. Abstract provided by Bazian Ltd, London