Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.

Indoor residual spraying (IRS) is one of the main malaria vector control strategies in Mozambique alongside the distribution of insecticide treated nets. As part of the national insecticide resistance management strategy, Mozambique introduced SumiShield™ 50WG, a third generation IRS product, in 201...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Helena Marti-Soler, Mara Máquina, Mercy Opiyo, Celso Alafo, Ellie Sherrard-Smith, Arlindo Malheia, Nelson Cuamba, Charfudin Sacoor, Regina Rabinovich, Pedro Aide, Francisco Saúte, Krijn Paaijmans
Formato:	article
Lenguaje:	EN
Publicado:	Public Library of Science (PLoS) 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/10abeecd96f84f589aa7d9c17eaf85fb
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:10abeecd96f84f589aa7d9c17eaf85fb
record_format	dspace
spelling	oai:doaj.org-article:10abeecd96f84f589aa7d9c17eaf85fb2021-12-02T20:15:14ZEffect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.1932-620310.1371/journal.pone.0248604https://doaj.org/article/10abeecd96f84f589aa7d9c17eaf85fb2021-01-01T00:00:00Zhttps://doi.org/10.1371/journal.pone.0248604https://doaj.org/toc/1932-6203Indoor residual spraying (IRS) is one of the main malaria vector control strategies in Mozambique alongside the distribution of insecticide treated nets. As part of the national insecticide resistance management strategy, Mozambique introduced SumiShield™ 50WG, a third generation IRS product, in 2018. Its residual efficacy was assessed in southern Mozambique during the 2018-2019 malaria season. Using a susceptible Anopheles arabiensis strain, residual efficacy was assessed on two different wall surfaces, cement and mud-plastered walls, using standard WHO (World Health Organization) cone bioassay tests at three different heights. Female mosquitoes of two age groups (2-5 and 13-26 day old) were exposed for 30 minutes, after which mortality was observed 24h, 48h, 72h, and 96h and 120h post-exposure to assess (delayed) mortality. Lethal times (LT) 90, LT50 and LT10 were estimated using Bayesian models. Mortality 24h post exposure was consistently below 80%, the current WHO threshold value for effective IRS, in both young and old mosquitoes, regardless of wall surface type. Considering delayed mortality, residual efficacies (mosquito mortality equal or greater than 80%) ranged from 1.5 to ≥12.5 months, with the duration depending on mortality time post exposure, wall type and mosquito age. Looking at mortality 72h after exposure, residual efficacy was between 6.5 and 9.5 months, depending on wall type and mosquito age. The LT50 and LT10 (i.e. 90% of the mosquitoes survive exposure to the insecticides) values were consistently higher for older mosquitoes (except for LT10 values for 48h and 72h post-exposure mortality) and ranged from 0.9 to 5.8 months and 0.2 to 7.8 months for LT50 and LT10, respectively. The present study highlights the need for assessing mosquito mortality beyond the currently recommended 24h post exposure. Failure to do so may lead to underestimation of the residual efficacy of IRS products, as delayed mortality will lead to a further reduction in mosquito vector populations and potentially negatively impact disease transmission. Monitoring residual efficacy on relevant wall surfaces, including old mosquitoes that are ultimately responsible for malaria transmission, and assessing delayed mortalities are critical to provide accurate and actionable data to guide vector control programmes.Helena Marti-SolerMara MáquinaMercy OpiyoCelso AlafoEllie Sherrard-SmithArlindo MalheiaNelson CuambaCharfudin SacoorRegina RabinovichPedro AideFrancisco SaúteKrijn PaaijmansPublic Library of Science (PLoS)articleMedicineRScienceQENPLoS ONE, Vol 16, Iss 8, p e0248604 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Helena Marti-Soler Mara Máquina Mercy Opiyo Celso Alafo Ellie Sherrard-Smith Arlindo Malheia Nelson Cuamba Charfudin Sacoor Regina Rabinovich Pedro Aide Francisco Saúte Krijn Paaijmans Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.
description	Indoor residual spraying (IRS) is one of the main malaria vector control strategies in Mozambique alongside the distribution of insecticide treated nets. As part of the national insecticide resistance management strategy, Mozambique introduced SumiShield™ 50WG, a third generation IRS product, in 2018. Its residual efficacy was assessed in southern Mozambique during the 2018-2019 malaria season. Using a susceptible Anopheles arabiensis strain, residual efficacy was assessed on two different wall surfaces, cement and mud-plastered walls, using standard WHO (World Health Organization) cone bioassay tests at three different heights. Female mosquitoes of two age groups (2-5 and 13-26 day old) were exposed for 30 minutes, after which mortality was observed 24h, 48h, 72h, and 96h and 120h post-exposure to assess (delayed) mortality. Lethal times (LT) 90, LT50 and LT10 were estimated using Bayesian models. Mortality 24h post exposure was consistently below 80%, the current WHO threshold value for effective IRS, in both young and old mosquitoes, regardless of wall surface type. Considering delayed mortality, residual efficacies (mosquito mortality equal or greater than 80%) ranged from 1.5 to ≥12.5 months, with the duration depending on mortality time post exposure, wall type and mosquito age. Looking at mortality 72h after exposure, residual efficacy was between 6.5 and 9.5 months, depending on wall type and mosquito age. The LT50 and LT10 (i.e. 90% of the mosquitoes survive exposure to the insecticides) values were consistently higher for older mosquitoes (except for LT10 values for 48h and 72h post-exposure mortality) and ranged from 0.9 to 5.8 months and 0.2 to 7.8 months for LT50 and LT10, respectively. The present study highlights the need for assessing mosquito mortality beyond the currently recommended 24h post exposure. Failure to do so may lead to underestimation of the residual efficacy of IRS products, as delayed mortality will lead to a further reduction in mosquito vector populations and potentially negatively impact disease transmission. Monitoring residual efficacy on relevant wall surfaces, including old mosquitoes that are ultimately responsible for malaria transmission, and assessing delayed mortalities are critical to provide accurate and actionable data to guide vector control programmes.
format	article
author	Helena Marti-Soler Mara Máquina Mercy Opiyo Celso Alafo Ellie Sherrard-Smith Arlindo Malheia Nelson Cuamba Charfudin Sacoor Regina Rabinovich Pedro Aide Francisco Saúte Krijn Paaijmans
author_facet	Helena Marti-Soler Mara Máquina Mercy Opiyo Celso Alafo Ellie Sherrard-Smith Arlindo Malheia Nelson Cuamba Charfudin Sacoor Regina Rabinovich Pedro Aide Francisco Saúte Krijn Paaijmans
author_sort	Helena Marti-Soler
title	Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.
title_short	Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.
title_full	Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.
title_fullStr	Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.
title_full_unstemmed	Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.
title_sort	effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (sumishield™ 50wg) in southern mozambique.
publisher	Public Library of Science (PLoS)
publishDate	2021
url	https://doaj.org/article/10abeecd96f84f589aa7d9c17eaf85fb
work_keys_str_mv	AT helenamartisoler effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT maramaquina effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT mercyopiyo effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT celsoalafo effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT elliesherrardsmith effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT arlindomalheia effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT nelsoncuamba effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT charfudinsacoor effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT reginarabinovich effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT pedroaide effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT franciscosaute effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique AT krijnpaaijmans effectofwalltypedelayedmortalityandmosquitoageontheresidualefficacyofaclothianidinbasedindoorresidualsprayformulationsumishield50wginsouthernmozambique
_version_	1718374567408304128

Effect of wall type, delayed mortality and mosquito age on the residual efficacy of a clothianidin-based indoor residual spray formulation (SumiShield™ 50WG) in southern Mozambique.

Ejemplares similares