Evaluation of the durability of long‐lasting insecticidal nets in Guatemala

Malaria Journal

Norma Padilla¹  José Guillermo Juárez¹  Juan Carlos Lol¹  Soledad Rodas¹  María Eugenia Castellanos²  Stephen C. Smith³  Audrey Lenhart³  Lucrecia Vizcaino³  Jodi Vanden Eng³  Sayra Chanquin⁴  Zoraida Morales⁵  Henok G. Woldu⁶ 

[1] Centro de Estudios en Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala;Centro de Estudios en Salud, Universidad del Valle de Guatemala, Guatemala City, Guatemala;Public Health and Tropical Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, Australia;Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, USA;Sección de Entomología Médica, Programa de Enfermedades Transmitidas por Vectores, Ministerio de Salud Pública y Asistencia Social, Guatemala City, Guatemala;Sub-programa de Malaria, Programa de Enfermedades Transmitidas por Vectores, Ministerio de Salud Pública y Asistencia Social, Guatemala City, Guatemala;The Center For Health Analytics For National and Global Equity (C.H.A.N.G.E.), Columbia, USA;

关键词: Insecticide-treated bed nets;    Malaria;    Long-lasting insecticidal nets;    Durability;    Deltamethrin;    attrition;    Survivorship;    Bio-efficacy;    Insecticide content;   

DOI  :  10.1186/s12936-021-03722-1

来源: Springer

【 摘 要 】

BackgroundInsecticide-treated bed nets (ITNs) are widely used for the prevention and control of malaria. In Guatemala, since 2006, ITNs have been distributed free of charge in the highest risk malaria-endemic areas and constitute one of the primary vector control measures in the country. Despite relying on ITNs for almost 15 years, there is a lack of data to inform the timely replacement of ITNs whose effectiveness becomes diminished by routine use.MethodsThe survivorship, physical integrity, insecticide content and bio-efficacy of ITNs were assessed through cross-sectional surveys conducted at 18, 24 and 32 months after a 2012 distribution of PermaNet® 2.0 in a malaria focus in Guatemala. A working definition of ‘LLIN providing adequate protection’ was developed based on the combination of the previous parameters and usage of the net. A total of 988 ITNs were analysed (290 at 18 months, 349 at 24 months and 349 at 32 months).ResultsThe functional survivorship of bed nets decreased over time, from 92% at 18 months, to 81% at 24 months and 69% at 32 months. Independent of the time of the survey, less than 80% of the bed nets that were still present in the household were reported to have been used the night before. The proportion of bed nets categorized as “in good condition” per World Health Organization (WHO) guidelines of the total hole surface area, diminished from 77% to 18 months to 58% at 32 months. The portion of ITNs with deltamethrin concentration less than 10 mg/m2 increased over time. Among the bed nets for which bioassays were conducted, the percentage that met WHO criteria for efficacy dropped from 90% to 18 months to 52% at 32 months. The proportion of long-lasting insecticidal nets (LLINs) providing adequate protection was 38% at 24 months and 21% at 32 months.ConclusionsAt 32 months, only one in five of the LLINs distributed in the campaign provided adequate protection in terms of survivorship, physical integrity, bio-efficacy and usage. Efforts to encourage the community to retain, use, and properly care for the LLINs may improve their impact. Durability assessments should be included in future campaigns.

【 授权许可】

CC BY