RESUMO
BACKGROUND: Armenia is considered particularly vulnerable to life-threatening vector-borne diseases (VBDs) including malaria, West Nile virus disease and leishmaniasis. However, information relevant for the control of the vectors of these diseases, such as their insecticide resistance profile, is scarce. The present study was conducted to provide the first evidence on insecticide resistance mechanisms circulating in major mosquito and sand fly populations in Armenia. METHODS: Sampling sites were targeted based mainly on previous historical records of VBD occurrences in humans and vertebrate hosts. Initially, molecular species identification on the collected vector samples was performed. Subsequently, molecular diagnostic assays [polymerase chain reaction (PCR), Sanger sequencing, PCR-restriction fragment length polymorphism (RFLP), quantitative PCR (qPCR)] were performed to profile for major insecticide resistance mechanisms, i.e. target site insensitivity in voltage-gated sodium channel (vgsc) associated with pyrethroid resistance, acetylcholinesterase (ace-1) target site mutations linked to organophosphate (OP) and carbamate (CRB) resistance, chitin synthase (chs-1) target site mutations associated with diflubenzuron (DFB) resistance and gene amplification of carboxylesterases (CCEs) associated with resistance to the OP temephos. RESULTS: Anopheles mosquitoes were principally represented by Anopheles sacharovi, a well-known malaria vector in Armenia, which showed no signs of resistance mechanisms. Contrarily, the knockdown resistance (kdr) mutations V1016G and L1014F/C in the vgsc gene were detected in the arboviral mosquito vectors Aedes albopictus and Culex pipiens, respectively. The kdr mutation L1014S was also detected in the sand fly, vectors of leishmaniasis, Phlebotomus papatasi and P. tobbi, whereas no mutations were found in the remaining collected sand fly species, P. sergenti, P. perfiliewi and P. caucasicus. CONCLUSIONS: This is the first study to report on molecular mechanisms of insecticide resistance circulating in major mosquito and sand fly disease vectors in Armenia and highlights the need for the establishment of systematic resistance monitoring practices for the implementation of evidence-based control applications.
Assuntos
Aedes , Anopheles , Culex , Inseticidas , Leishmaniose , Malária , Phlebotomus , Psychodidae , Piretrinas , Animais , Humanos , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mosquitos Vetores/genética , Acetilcolinesterase/genética , Anopheles/genética , Armênia , Phlebotomus/genética , MutaçãoRESUMO
BACKGROUND: In 2016, a field study was implemented in all Armenian provinces in order to update knowledge on the presence and distribution of both native and invasive mosquito species. Larvae and adult mosquitoes were sampled and identified on the basis of their morphology. Supplementary field surveys were performed in 2017-2018. RESULTS: Between June 20 and July 12, 2016, 117 localities were visited. A total number of 197 sampling units were checked, of which 143 (73%) were positive for mosquitoes (with 1-6 species per sampling unit). A total number of 4157 mosquito specimens were identified to species or species complex level. Ten species represent first records for Armenia: Aedes albopictus, Ae. annulipes, Ae. cataphylla, Ae. cinereus/geminus (probably Ae. cinereus), Ae. flavescens, Anopheles plumbeus, Coquillettidia richiardii, Culex martinii, Cx. torrentium and Culiseta subochrea. The invasive species Ae. albopictus was recorded in a single locality (Bagratashen) at the border point with Georgia, along the main road Tbilisi-Yerevan. This species was further recorded in 2017 and 2018, demonstrating its establishment and spread in north Armenia. These surveys confirm the presence of vectors of malaria parasites (in particular An. sacharovi) and West Nile virus (Cx. pipiens). CONCLUSION: The knowledge of the Armenian mosquito fauna is extended to a list of 28 species. The record of Aedes albopictus, an important potential vector of many arboviruses, has important implications for public health.
TITLE: Les moustiques d'Arménie : synthèse des connaissances et résultats d'une étude de terrain avec une première mention pour Aedes albopictus. ABSTRACT: Contexte : En 2016, nous avons réalisé une étude sur le terrain dans toutes les provinces du pays dans le but d'actualiser la présence et la distribution des espèces de moustiques aussi bien natives qu'invasives. Les moustiques récoltés aux stades larvaires et adultes ont été identifiés sur des critères morphologiques. Des suivis additionnels ont été réalisés en 2017 et 2018. Résultats : Entre le 20 juin et le 12 juillet 2016, 117 localités ont été visitées. Au total, 197 unités de collecte ont été prospectées dont 143 (73%) se sont révélées positives pour les moustiques (avec de 1 à 6 espèces par unité de collecte). Au total, 4157 spécimens ont été identifiés au niveau de l'espèce ou du complexe d'espèces. Dix espèces ont été observées pour la première fois en Arménie : Aedes albopictus, Ae. annulipes, Ae. cataphylla, Ae. cinereus/geminus (probablement Ae. cinereus), Ae. flavescens, Anopheles plumbeus, Coquillettidia richiardii, Culex martinii, Cx. torrentium et Culiseta subochrea. L'espèce invasive Ae. albopictus a été observée dans une seule localité (Bagratashen) à la frontière avec la Géorgie, sur l'axe routier principal Tbilisi-Yerevan. Cette espèce a également été observée en 2017 et en 2018, faisant la preuve de son installation et de sa diffusion dans le nord de l'Arménie. Ces suivis confirment la présence des vecteurs de Plasmodium humains (en particulier An. sacharovi) et du virus West Nile (Cx. pipiens). Conclusion : La connaissance de la faune culicidienne d'Arménie progresse, avec une liste actualisée à 28 espèces. L'observation d'Aedes albopictus, un important vecteur potentiel de nombreux arbovirus, a d'importantes implications en termes de santé publique.
