학술논문
The impact of pyrethroid-pyriproxyfen and pyrethroid-chlorfenapyr long-lasting insecticidal nets on density of primary malaria vectors Anopheles gambiae s.s. and Anopheles coluzzii in Benin: a secondary analysis of a cluster randomised controlled trial
Document Type
Report
Author
Yovogan, Boulais; Sovi, Arthur; Djènontin, Armel; Adoha, Constantin J.; Akinro, Bruno; Accrombessi, Manfred; Dangbénon, Edouard; Koukpo, Come Z.; Affolabi, Zul-Kifl; Agboho, Prudenciène A.; Kpanou, Casimir Dossou; Assongba, Landry; Missihoun, Antoine Abel; Tokponnon, Tatchémè Filémon; Agbangla, Clément; Padonou, Germain Gil; Messenger, Louisa A.; Ngufor, Corine; Cook, Jackie; Akogbéto, Martin C.; Protopopoff, Natacha
Source
Parasites & Vectors. January 4, 2024, Vol. 17 Issue 1
Subject
Language
English
ISSN
1756-3305
Abstract
Author(s): Boulais Yovogan[sup.1,2], Arthur Sovi[sup.2,3,4], Armel Djènontin[sup.1,2], Constantin J. Adoha[sup.1,2], Bruno Akinro[sup.2], Manfred Accrombessi[sup.4], Edouard Dangbénon[sup.2], Come Z. Koukpo[sup.2], Zul-Kifl Affolabi[sup.2], Prudenciène A. Agboho[sup.2], Casimir Dossou Kpanou[sup.2], Landry Assongba[sup.2], Antoine [...]
Background Long-lasting insecticidal nets (LLINs) may have different impacts on distinct mosquito vector species. We assessed the efficacy of pyrethroid-pyriproxyfen and pyrethroid-chlorfenapyr LLINs on the density of Anopheles gambiae s.s. and An. coluzzii compared to pyrethroid-only nets in a three-arm cluster randomised control trial in Benin. Methods Indoor and outdoor collections of adult mosquitoes took place in 60 clusters using human landing catches at baseline and every 3 months for 2 years. After morphological identification, around 15% of randomly selected samples of An. gambiae s.l. were dissected to determine parity, species (using PCR). Results Overall, a total of 46,613 mosquito specimens were collected at baseline and 259,250 in the eight quarterly collections post-net distribution. Post-net distribution, approximately 70% of the specimens of An. gambiae s.l. speciated were An. coluzzii, while the rest were mostly composed of An. gambiae s.s. with a small proportion (< 1%) of hybrids (An. gambiae/coluzzii). There was no evidence of a significant reduction in vector density indoors in either primary vector species [An. coluzzii: DR (density ratio) = 0.62 (95% CI 0.21-1.77), p = 0.3683 for the pyrethroid-pyriproxyfen LLIN and DR = 0.56 (95% CI 0.19-1.62), p = 0.2866 for the pyrethroid-chlorfenapyr LLIN, An. gambiae s.s.: DR = 0.52 (95% CI 0.18-1.46), p = 0.2192 for the pyrethroid-pyriproxyfen LLIN and DR = 0.53 (95% CI 0.19-1.46), p = 0.2222 for the pyrethroid-chlorfenapyr]. The same trend was observed outdoors. Parity rates of An. gambiae s.l. were also similar across study arms. Conclusions Compared with pyrethroid-only LLINs, pyrethroid-chlorfenapyr LLINs and pyrethroid-pyriproxyfen LLINs performed similarly against the two primary mosquito species An. gambiae s.s. and An. coluzzii in Benin. Graphical Abstract Keywords: Dual active-ingredients LLINs, Density, Anopheles coluzzii, Anopheles gambiae s.s., Benin
Background Long-lasting insecticidal nets (LLINs) may have different impacts on distinct mosquito vector species. We assessed the efficacy of pyrethroid-pyriproxyfen and pyrethroid-chlorfenapyr LLINs on the density of Anopheles gambiae s.s. and An. coluzzii compared to pyrethroid-only nets in a three-arm cluster randomised control trial in Benin. Methods Indoor and outdoor collections of adult mosquitoes took place in 60 clusters using human landing catches at baseline and every 3 months for 2 years. After morphological identification, around 15% of randomly selected samples of An. gambiae s.l. were dissected to determine parity, species (using PCR). Results Overall, a total of 46,613 mosquito specimens were collected at baseline and 259,250 in the eight quarterly collections post-net distribution. Post-net distribution, approximately 70% of the specimens of An. gambiae s.l. speciated were An. coluzzii, while the rest were mostly composed of An. gambiae s.s. with a small proportion (< 1%) of hybrids (An. gambiae/coluzzii). There was no evidence of a significant reduction in vector density indoors in either primary vector species [An. coluzzii: DR (density ratio) = 0.62 (95% CI 0.21-1.77), p = 0.3683 for the pyrethroid-pyriproxyfen LLIN and DR = 0.56 (95% CI 0.19-1.62), p = 0.2866 for the pyrethroid-chlorfenapyr LLIN, An. gambiae s.s.: DR = 0.52 (95% CI 0.18-1.46), p = 0.2192 for the pyrethroid-pyriproxyfen LLIN and DR = 0.53 (95% CI 0.19-1.46), p = 0.2222 for the pyrethroid-chlorfenapyr]. The same trend was observed outdoors. Parity rates of An. gambiae s.l. were also similar across study arms. Conclusions Compared with pyrethroid-only LLINs, pyrethroid-chlorfenapyr LLINs and pyrethroid-pyriproxyfen LLINs performed similarly against the two primary mosquito species An. gambiae s.s. and An. coluzzii in Benin. Graphical Abstract Keywords: Dual active-ingredients LLINs, Density, Anopheles coluzzii, Anopheles gambiae s.s., Benin