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Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial

Outdoor and early biting by mosquitoes challenge the efficacy of bed nets and indoor residual spraying against malaria in the Greater Mekong Subregion. The objective of this study was to assess the efficacy of outdoor residual spraying (ORS) for malaria vector-control in this region. A cluster rando...

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Autores principales: Chaumeau, Victor, Kajeechiwa, Ladda, Kulabkeeree, Thithiworada, Sawasdichai, Sunisa, Haohankhunnatham, Warat, Inta, Aritsara, Phanaphadungtham, Monthicha, Girond, Florian, Herbreteau, Vincent, Delmas, Gilles, Nosten, François
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9462579/
https://www.ncbi.nlm.nih.gov/pubmed/36083983
http://dx.doi.org/10.1371/journal.pone.0274320
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author Chaumeau, Victor
Kajeechiwa, Ladda
Kulabkeeree, Thithiworada
Sawasdichai, Sunisa
Haohankhunnatham, Warat
Inta, Aritsara
Phanaphadungtham, Monthicha
Girond, Florian
Herbreteau, Vincent
Delmas, Gilles
Nosten, François
author_facet Chaumeau, Victor
Kajeechiwa, Ladda
Kulabkeeree, Thithiworada
Sawasdichai, Sunisa
Haohankhunnatham, Warat
Inta, Aritsara
Phanaphadungtham, Monthicha
Girond, Florian
Herbreteau, Vincent
Delmas, Gilles
Nosten, François
author_sort Chaumeau, Victor
collection PubMed
description Outdoor and early biting by mosquitoes challenge the efficacy of bed nets and indoor residual spraying against malaria in the Greater Mekong Subregion. The objective of this study was to assess the efficacy of outdoor residual spraying (ORS) for malaria vector-control in this region. A cluster randomized controlled trial was conducted between July 2018 and April 2019 in twelve villages in Karen (Kayin) state, Myanmar. Villages were randomly assigned to receive either a single round of ORS with a capsule suspension of lambda-cyhalothrin for two days in October or no intervention (six villages per group). The primary endpoint was the biting rate of malaria mosquitoes assessed with human-landing catch and cow-baited trap collection methods, and was analyzed with a Bayesian multi-level model. In the intervention villages, the proportion of households located within the sprayed area ranged between 42 and 100% and the application rate ranged between 63 and 559 g of active ingredient per hectare. At baseline, the median of Anopheles biting rate estimates in the twelve villages was 2 bites per person per night (inter-quartile range [IQR] 0–5, range 0–48) indoors, 6 bites per person per night (IQR 2–16, range 0–342) outdoors and 206 bites per cow per night (IQR 83–380, range 19–1149) in the cow-baited trap. In intention-to-treat analysis, it was estimated that ORS reduced biting rate by 72% (95% confidence interval [CI] 63–79) from Month 0 to Month 3 and by 79% (95% CI 62–88) from Month 4 to Month 6, considering control villages as the reference. In conclusion, ORS rapidly reduces the biting rates of malaria mosquitoes in a Southeast Asian setting where the vectors bite mostly outdoors and at a time when people are not protected by mosquito bed nets.
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spelling pubmed-94625792022-09-10 Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial Chaumeau, Victor Kajeechiwa, Ladda Kulabkeeree, Thithiworada Sawasdichai, Sunisa Haohankhunnatham, Warat Inta, Aritsara Phanaphadungtham, Monthicha Girond, Florian Herbreteau, Vincent Delmas, Gilles Nosten, François PLoS One Research Article Outdoor and early biting by mosquitoes challenge the efficacy of bed nets and indoor residual spraying against malaria in the Greater Mekong Subregion. The objective of this study was to assess the efficacy of outdoor residual spraying (ORS) for malaria vector-control in this region. A cluster randomized controlled trial was conducted between July 2018 and April 2019 in twelve villages in Karen (Kayin) state, Myanmar. Villages were randomly assigned to receive either a single round of ORS with a capsule suspension of lambda-cyhalothrin for two days in October or no intervention (six villages per group). The primary endpoint was the biting rate of malaria mosquitoes assessed with human-landing catch and cow-baited trap collection methods, and was analyzed with a Bayesian multi-level model. In the intervention villages, the proportion of households located within the sprayed area ranged between 42 and 100% and the application rate ranged between 63 and 559 g of active ingredient per hectare. At baseline, the median of Anopheles biting rate estimates in the twelve villages was 2 bites per person per night (inter-quartile range [IQR] 0–5, range 0–48) indoors, 6 bites per person per night (IQR 2–16, range 0–342) outdoors and 206 bites per cow per night (IQR 83–380, range 19–1149) in the cow-baited trap. In intention-to-treat analysis, it was estimated that ORS reduced biting rate by 72% (95% confidence interval [CI] 63–79) from Month 0 to Month 3 and by 79% (95% CI 62–88) from Month 4 to Month 6, considering control villages as the reference. In conclusion, ORS rapidly reduces the biting rates of malaria mosquitoes in a Southeast Asian setting where the vectors bite mostly outdoors and at a time when people are not protected by mosquito bed nets. Public Library of Science 2022-09-09 /pmc/articles/PMC9462579/ /pubmed/36083983 http://dx.doi.org/10.1371/journal.pone.0274320 Text en © 2022 Chaumeau et al https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
spellingShingle Research Article
Chaumeau, Victor
Kajeechiwa, Ladda
Kulabkeeree, Thithiworada
Sawasdichai, Sunisa
Haohankhunnatham, Warat
Inta, Aritsara
Phanaphadungtham, Monthicha
Girond, Florian
Herbreteau, Vincent
Delmas, Gilles
Nosten, François
Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial
title Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial
title_full Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial
title_fullStr Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial
title_full_unstemmed Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial
title_short Outdoor residual spraying for malaria vector-control in Kayin (Karen) state, Myanmar: A cluster randomized controlled trial
title_sort outdoor residual spraying for malaria vector-control in kayin (karen) state, myanmar: a cluster randomized controlled trial
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9462579/
https://www.ncbi.nlm.nih.gov/pubmed/36083983
http://dx.doi.org/10.1371/journal.pone.0274320
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