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Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar

BACKGROUND: In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of th...

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Autores principales: Raharimalala, Fara Nantenaina, Ravaomanarivo, Lala Harivelo, Ravelonandro, Pierre, Rafarasoa, Lala Sahondra, Zouache, Karima, Tran-Van, Van, Mousson, Laurence, Failloux, Anna-Bella, Hellard, Eléonore, Moro, Claire Valiente, Ralisoa, Bakoly Olga, Mavingui, Patrick
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3359177/
https://www.ncbi.nlm.nih.gov/pubmed/22433186
http://dx.doi.org/10.1186/1756-3305-5-56
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author Raharimalala, Fara Nantenaina
Ravaomanarivo, Lala Harivelo
Ravelonandro, Pierre
Rafarasoa, Lala Sahondra
Zouache, Karima
Tran-Van, Van
Mousson, Laurence
Failloux, Anna-Bella
Hellard, Eléonore
Moro, Claire Valiente
Ralisoa, Bakoly Olga
Mavingui, Patrick
author_facet Raharimalala, Fara Nantenaina
Ravaomanarivo, Lala Harivelo
Ravelonandro, Pierre
Rafarasoa, Lala Sahondra
Zouache, Karima
Tran-Van, Van
Mousson, Laurence
Failloux, Anna-Bella
Hellard, Eléonore
Moro, Claire Valiente
Ralisoa, Bakoly Olga
Mavingui, Patrick
author_sort Raharimalala, Fara Nantenaina
collection PubMed
description BACKGROUND: In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. METHODS: The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 10(7.5 )pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. RESULTS: The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 × 10(-16)) and period (F = 36.22, p = 2.548 × 10(-13)), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. CONCLUSION: In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion.
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spelling pubmed-33591772012-05-24 Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar Raharimalala, Fara Nantenaina Ravaomanarivo, Lala Harivelo Ravelonandro, Pierre Rafarasoa, Lala Sahondra Zouache, Karima Tran-Van, Van Mousson, Laurence Failloux, Anna-Bella Hellard, Eléonore Moro, Claire Valiente Ralisoa, Bakoly Olga Mavingui, Patrick Parasit Vectors Research BACKGROUND: In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. METHODS: The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 10(7.5 )pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. RESULTS: The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 × 10(-16)) and period (F = 36.22, p = 2.548 × 10(-13)), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. CONCLUSION: In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion. BioMed Central 2012-03-20 /pmc/articles/PMC3359177/ /pubmed/22433186 http://dx.doi.org/10.1186/1756-3305-5-56 Text en Copyright ©2012 Raharimalala et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Raharimalala, Fara Nantenaina
Ravaomanarivo, Lala Harivelo
Ravelonandro, Pierre
Rafarasoa, Lala Sahondra
Zouache, Karima
Tran-Van, Van
Mousson, Laurence
Failloux, Anna-Bella
Hellard, Eléonore
Moro, Claire Valiente
Ralisoa, Bakoly Olga
Mavingui, Patrick
Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar
title Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar
title_full Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar
title_fullStr Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar
title_full_unstemmed Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar
title_short Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar
title_sort biogeography of the two major arbovirus mosquito vectors, aedes aegypti and aedes albopictus (diptera, culicidae), in madagascar
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3359177/
https://www.ncbi.nlm.nih.gov/pubmed/22433186
http://dx.doi.org/10.1186/1756-3305-5-56
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