Reproduction de : Thèse d'exercice : Médecine vétérinaire : Toulouse 3 : 2008. / Titre provenant de l'écran titre. Bibliogr. p 131-141.

Objective: To assess the presence of Dengue, Chikungunya, and Zika in serum samples of patients with acute febrile illness in Piura, Peru and describe the most common clinical features. Results: Dengue was the most common arbovirus detected in 170/496 (34.3%), followed by Zika in 39/496 (7.9%) and Chikungunya in 23/496 (4.6%). Among the 170 samples positive for Dengue, serotype 2 was the most predominant type present in 97/170 (57.1%) of samples, followed by the serotype 3 in 9/170 (5.3%). Headaches, muscle pain, and joint pain were the most common symptoms associated with fever in patients with Dengue and Zika. No symptoms predominance was observed in patients with Chikungunya.Dengue is considered the most frequent arbovirus in Peru and the number of cases has increased dramatically in the last 5 years. However, it is not the only arbovirus that circulates along the northern coast of Peru. It has also been determined the presence of Zika and Chikungunya in our population, which may suggest the circulation of other arboviruses that have not been detected.

Objective: To evaluate the frequency of infection caused by the Oropouche virus (OROV) in 496 patients with acute febrile disease (AFI), whose samples were obtained for the analysis of endemic arboviruses in a previous investigation carried out in 2016. Results: OROV was detected in 26.4% (131/496) of serum samples from patients with AFI. Co-infections with Dengue virus (7.3%), Zika virus (1.8%) and Chikungunya (0.2%) were observed. The most common clinical symptoms reported among the patients with OROV infections were headache 85.5% (112/131), myalgia 80.9% (106/131), arthralgia 72.5% (95/131) and loss of appetite 67.9% (89/131). Headache and myalgia were predominant in all age groups. Both OROV infections and co-infections were more frequent in May, June and July corresponding to the dry season of the region. / Revisión por pares

Objective: To describe the prevalence of dengue virus serotypes, as well as other viral and bacterial pathogens that cause acute febrile illness during an outbreak in Cajamarca in 2016. Results: Dengue virus (DENV) was the most frequent etiologic agent detected in 25.8% of samples (32/124), followed by Rickettsia spp. in 8.1% (10/124), Zika virus in 4.8% (6/124), Chikungunya virus 2.4% (3/124) and Bartonella bacilliformis 1.6% (2/124) cases. No positive cases were detected of Oropouche virus and Leptospira spp. DENV serotypes identification was only achieved in 23% of the total positive for DENV, two samples for DENV-2 and four samples for DENV-4. During the 2016 outbreak in Cajamarca-Peru, it was observed that in a large percentage of positive samples for DENV, the infecting serotype could not be determined by conventional detection assays. This represents a problem for the national surveillance system and for public health due to its epidemiological and clinical implications. Other viral and bacterial pathogens responsible for acute febrile syndrome were less frequently identified. / Revisión por pares

No grupo das doenças infecciosas emergentes e reemergentes, os arbovírus transmitidos por mosquitos, são considerados importantes desafios para a saúde pública. O alastramento mundial do vírus Chikungunya (CHIKV, Togaviridae, Alphavirus), acabou resultando na introdução do CHIKV no Brasil, através da transmissão zoonótica por mosquitos do gênero Aedes spp, particularmente Ae. aegypti e Ae. albopictus, duas espécies invasoras e cosmopolitas. Outro Alphavirus, o vírus Mayaro (MAYV) presente na região amazônica da América do Sul, vem apresentando indícios de uma real urbanização, elevando a preocupação sobre sua possível transmissão por mosquitos urbanos. Diante desse cenário, fica clara a necessidade da realização de estudos sobre estratégias de controle e prevenção da infecção por MAYV e CHIKV, uma vez que não há vacinas ou terapia antiviral específica para a infecção por esses arbovírus. Este projeto descreve pela primeira vez a eficiente expressão, purificação e análise de partículas semelhantes a vírus (VLP, virus-like particles) dos Alphavirus CHIKV e MAYV em células de inseto S2 (Drosophila melanogaster). Para esse fim, clonamos os genes das proteínas estruturais dos vírus MAYV e CHIKV em vetores para a expressão recombinante em células S2. Essa plataforma de expressão de proteínas provou ser adequada para o processamento de glicoproteínas do CHIKV e MAYV para produção de VLP, uma vez que detectamos a presença de partículas no sobrenadante do cultivo por Western blotting e Microscopia eletrônica de transmissão (TEM). Ainda, foi possível selecionar células para uma maior produção de VLP e estabelecer um método de purificação das partículas. / In the group of emerging and reemerging infectious diseases, mosquito-borne arboviruses are considered major public health challenges. The transmission of Chikungunya (CHIKV, Togaviridae, Alphavirus) in America continent was first reported in Central America and Caribbean region The CHIKV epidemics reached Brazil through zoonotic transmission by Aedes spp mosquitoes, particularly Ae. Aegypti and Ae. albopictus, two invasive and cosmopolitan species. Another Alphavirus, the Mayaro virus (MAYV) present mainly in the Amazon region has been showing evidence of a real urbanization, increasing concerns about its transmission by urban mosquitoes. Therefore, it is clear that studies on strategies for the control and prevention of MAYV and CHIKV infection are needed. Currently no vaccines or antiviral therapy specific for CHIKV and MAYV infection are available. This work describes for the first time an efficient expression, purification and analysis of virus-like particles (VLP) of CHIKV and MAYV Alphaviruses in S2 (Drosophila melanogaster) insect cells. The genes coding for the structural proteins of the MAYV and CHIKV viruses were cloned into vectors for recombinant expression in S2 cells. This platform proved to be suitable for the processing of CHIKV and MAYV glycoproteins and to produce VLP, since we detected the presence of particles in the culture supernatant by Western blotting and Transmission Electron Microscopy (TEM). Furthermore, it was possible to select cells for greater production of VLP and to establish a method for particle purification.

Devido a existência de 2 alphavírus artritogênicos no Brasil, os vírus Mayaro (MAYV) e Chikungunya (CHIKV) tornou-se importante desenvolver testes diagnósticos eficazes para discriminar suas infecções. No presente trabalho, desenvolvemos ELISAs indiretos para diagnóstico de CHIKV e MAYV utilizando proteínas de envelope viral E2 recombinantes, produzidas em Escherichia coli, as rE2-CHIKV e rE2-MAYV ELISAs. As proteínas E2 recombinantes tiveram suas antigenicidades verificadas nos ensaios utilizando anticorpos policlonais oriundos de camundongos hiperimunizados com CHIKV, MAYV e outros alphavírus. O rE2-CHIKV ELISA detectou anticorpos murinos de forma homotípica e não produziu reações cruzadas evidenciáveis utilizando anticorpos murinos específicos contra outros Alphavírus. O rE2-MAYV ELISA detectou anticorpos murinos homotípicos e também, reagiu cruzadamente com anticorpos murinos anti-CHIKV, mas não para outros Alphavírus. Esses ELISAs, também, foram usados na detecção de anticorpos em soros de pacientes com suspeita de infecção arboviral. Pelo o rE2-CHIKV ELISA, testaram-se 59 soros, resultando em 26 amostras IgG positivas. Resultados desse ELISA, quando comparados aos obtidos por teste de neutralização, demonstraram sensibilidade de 89,66% e especificidade de 100%. Soros humanos IgG positivos foram detectados em altas diluições pelo rE2-CHIKV ELISA. Quanto a detecção de IgM, o rE2- CHIKV ELISA apresentou moderada concordância com outros ensaios sorológicos. Com rE2- MAYV ELISA, testaram-se 68 soros resultando em 23 amostras IgG positivas, das quais 11 também mostraram-se positivas em teste de neutralização, demonstrando sensibilidade de 100% e especificidade de 78,95%. Portanto, os rE2-CHIKV e rE2 MAYV ELISAs, particularmente para detecção de IgG, mostraram-se adequadamente sensíveis e específicos para serem validados em estudos com maiores números de amostras e serem aplicados ao diagnóstico de pacientes infectados com CHIKV e MAYV. / Due the existence of 2 arthritogenic alphaviruses in Brasil, the viruses Mayaro (MAYV) and Chikungunya (CHIKV), it became important the development of efficient diagnose tests to discriminate their infections. In the present work, we developed indirect ELISAs for CHIKV and MAYV diagnosis using viral recombinant envelope proteins E2, produced in Escherichia coli, the rE2-CHIKV and rE2-MAYV. The recombinant E2 proteins had their antigenicity confirmed in the assay by using polyclonal antibodies produced in hyperimmunized mice with CHIKV, MAYV and other alphaviruses. The rE2-CHIKV ELISA detected homotypic murine antibodies and did not produced detectable cross-reactivity signal when using murine antibodies from other alphaviruses. The rE2-MAYV ELISA detected homotypic antibodies and also cross-reacted with murine anti-CHIKV antibodies, but not to other alphaviruses. These ELISAs were also tested for the detection of human antibodies, using patient sera suspected of arboviral infection. For rE2- CHIKV ELISA, it were tested 59 sera, resulting in 26 positive IgG samples. These ELISA results, when compared to those of a neutralizing assay, demonstrated a sensibility of 89.66% and specificity of 100%. The IgG positive human sera were detected in high dilutions by rE2-CHIKV ELISA. Regarding the detection of IgM, the rE2-CHIKV ELISA showed a moderate samples detection agreement when compared to other serologic assays. For rE2-MAYV ELISA, it were tested 68 sera, resulting in 23 positive IgG samples, of which 11 demonstrated to be positive by the neutralization assay, demonstrating a sensibility of 100% and specificity of 78.95%. Therefore, the rE2-CHIKV and rE2-MAYV ELISAs, especially for IgG detection, demonstrated to be properly sensitive and specific to be validated in studies using a greater number of samples, and also to be applied in the diagnosis of infected CHIKV and MAYV patients.

La dengue et le chikungunya sont des maladies transmises par Aedes aegypti et Aedes albopictus pouvant causer des pathologies sévères et des atteintes incapacitantes chroniques. Ce sont aussi les maladies qui se diffusent le plus rapidement, en partie à cause du changement climatique. Le Vietnam est une zone d’hyperendémicité pour la dengue et à risque pour le chikungunya comme le Cambodge voisin qui est atteint par les deux maladies.et représente une source de diffusion. L’objectif de cette thèse est d’évaluer le statut de ces deux maladies et la présence du chikungunya, d’évaluer l’efficacité du système de surveillance et d’évaluer la diversité des populations de moustiques vecteurs et leurs rôles respectifs dans la transmission. Une première partie de la thèse est dévolue à une revue bibliographique. La seconde partie comprend trois chapitres associés à trois publications. Le premier chapitre est consacré à une étude de la surveillance à l’hôpital général de la province sud de Dong Thap. Une cohorte de 131 patents avec une fièvre aigue a été étudiée pour tester la présence de dengue et de chikungunya. 101 patients sur 131 ont été positifs pour la dengue et les quatre sérotypes ont été détectés avec une prédominance de DENV1 et DENV4. Aucun cas de chikungunya n’a été détecté. Une variation d’efficacité dans la détection sérologique de la dengue a été observée avec un passage de 29% lors de l’admission à 53% sept jours après admission. Il y a donc clairement un risque de sous-estimation de la dengue alors que le chikungunya, n’est pas du tout testé. Des changements dans la procédure de détection et de surveillance sont proposés pour améliorer l’efficacité de la surveillance et surveiller l’émergence du chikungunya. Le deuxième chapitre est consacré à l’étude du rôle respectif d’A. aegypti et A. albopictus dans l’épidémie de Dengue de 2011 à Hanoi. Seuls DENV1 et DENV2 ont été détectés chez les 140 patients étudiés. Une corrélation positive a été observée entre la densité de population d’A. aegypti et le nombre de cas humains et la durée des épidémies. Ceci n’a pas été observé chez A. albopictus. Trois lots d’A. aegypti se sont révélés positifs pour la dengue, deux pour DENV1 et un pour DENV2. Cette étude montre clairement le rôle d’A. aegypti dans l’épidémie de 2011 à Hanoi. Le dernier chapitre est consacré à une analyse transversale sur 5 provinces frontalières du Laos et du Cambodge. 558 sérums collectés chez des patients admis pour fièvre aigue et de symptômes compatibles avec la dengue et chikungunya entre 2012 et 2014 dans des centres de médecine préventive. Les quatre sérotypes ont été détectés mais pas tous dans la même province. Seulement deux sérotypes ont été détectés au maximum dans une même province. Le chikungunya n’a pas été détecté. Un total de 1104 moustiques adultes a été prélevé dans les mêmes zones à l’intérieur et à l’extérieur des habitations. La densité de population de moustiques et les indices entomologiques ont été évalués suite à la capture de larves. Des densités très différentes ont été observées et la densité la plus importante a été obtenue dans la province de Long An, voisine du Cambodge. Le virus de la dengue a été détecté principalement chez A. albopictus. Le virus du chikungunya a également été détecté chez A. albopictus. L’analyse phylogénétique des moustiques collectés a montré une grande diversité génétique avec des génotypes décrits sur d’autres continents. Cette partie de la thèse met en évidence le rôle différentiel d’A. aegypti et A. albopictus, le rôle croissant de ce dernier et le transport anthropique des moustiques sur de grandes distances. Ce travail souligne le besoin de nouvelles approches de surveillance, au niveau clinique et au niveau entomologique, pour s’attaquer de façon efficace au risque épidémique de dengue et de chikungunya. / Dengue and chikungunya are both transmitted by Aedes aegypti and Aedes albopictus and can cause potentially severe and or debilitating chronic disease. They are the fastest spreading diseases, in part because of the climate change. Vietnam is a hyperendemicity country for dengue and is at risk to be like neighboring Cambodia affected both by dengue and chikungunya and be an overlapping area of distribution for both viruses. The aim of this PhD work was therefore to assess the status of single and dual infections all over the country, investigate the presence of chikungunya, assess the efficiency of the surveillance procedures routinely established and assess the diversity of mosquito populations and their potential respective role. A first part of the PhD dissertation is devoted to a bibliographic review. The second part comprises three chapters associated to three different publications. The first chapter is devoted to a surveillance study in the general hospital if the Southern Province of Dong Thap. A cohort of 131 patients with acute fever symptoms was investigated for the presence of dengue and chikungunya. 101 patients out of 131 were confirmed with dengue. All four dengue serotypes were detected with a predominance of DENV2 and DENV4. No chikungunya infection was detected although reported in neighboring Cambodia. A differential efficiency of serological dengue detection was observed. Efficiency was 29% upon admission and 53% after seven days on the same patients. There is thus a clear risk of dengue being underestimated while chikungunya is not systematically detected. Changes in detection and surveillance procedures are therefore proposed to increase the efficiency of dengue detection and continue the monitoring the emergence of CHIKV. The second Chapter is dedicated to the respective role of A. aegypti and A. albopictus in the 2011 outbreak in the Northern capital city of Hanoi. Only DENV-1 and DENV-2 serotypes were detected from the 140 patients hospitalized. A positive correlation was found between the population density of A. aegypti and the number of human cases and duration of outbreaks. This was not observed for A. albopictus. Three pools of A. aegypti were positive with dengue virus, two with DENV-1 and one with DENV-2. This work indicate clearly the role of A. aegypti in the 2011 Hanoi epidemics. The last chapter of the PhD is devoted to a crosscutting country wide survey in five provinces border with Lao PDR and Cambodia. In this work, a total of 558 serum samples were collected from patients admitted in the 2012-2014 period in five provincial preventive medicine centers with acute fever and symptoms compatible to DENV-CHIKV infection. All four dengue serotypes were found altogether but not in the same province. Only two serotypes were found at the maximum in a single province. No CHIKV was detected. A total of 1104 adult mosquitoes were collected inside and outside houses at the same place. Mosquito population density and vector indexes were assessed following capture of larvae. Differing densities of mosquito populations were found with the highest one being in the Long An province border with Cambodia. Dengue viruses were detected mostly in A. albopictus. CHIKV was also detected in A. albopictus mosquitoes. The phylogenetic analysis of the collected mosquitoes showed a large diversity of genotypes, all of them having been described in other parts of the world. This part of the PhD work underline the dual role of A. aegypti and A. albopictus, the increasing role of the latter and the high level of man-related very long distance mobility of mosquitoes. This work underlines the need of novel approaches for surveillance both at the clinical and at the entomological level to efficiently tackle the risk of dengue and chikungunya outbreaks.

Devido a existência de 2 alphavírus artritogênicos no Brasil, os vírus Mayaro (MAYV) e Chikungunya (CHIKV) tornou-se importante desenvolver testes diagnósticos eficazes para discriminar suas infecções. No presente trabalho, desenvolvemos ELISAs indiretos para diagnóstico de CHIKV e MAYV utilizando proteínas de envelope viral E2 recombinantes, produzidas em Escherichia coli, as rE2-CHIKV e rE2-MAYV ELISAs. As proteínas E2 recombinantes tiveram suas antigenicidades verificadas nos ensaios utilizando anticorpos policlonais oriundos de camundongos hiperimunizados com CHIKV, MAYV e outros alphavírus. O rE2-CHIKV ELISA detectou anticorpos murinos de forma homotípica e não produziu reações cruzadas evidenciáveis utilizando anticorpos murinos específicos contra outros Alphavírus. O rE2-MAYV ELISA detectou anticorpos murinos homotípicos e também, reagiu cruzadamente com anticorpos murinos anti-CHIKV, mas não para outros Alphavírus. Esses ELISAs, também, foram usados na detecção de anticorpos em soros de pacientes com suspeita de infecção arboviral. Pelo o rE2-CHIKV ELISA, testaram-se 59 soros, resultando em 26 amostras IgG positivas. Resultados desse ELISA, quando comparados aos obtidos por teste de neutralização, demonstraram sensibilidade de 89,66% e especificidade de 100%. Soros humanos IgG positivos foram detectados em altas diluições pelo rE2-CHIKV ELISA. Quanto a detecção de IgM, o rE2- CHIKV ELISA apresentou moderada concordância com outros ensaios sorológicos. Com rE2- MAYV ELISA, testaram-se 68 soros resultando em 23 amostras IgG positivas, das quais 11 também mostraram-se positivas em teste de neutralização, demonstrando sensibilidade de 100% e especificidade de 78,95%. Portanto, os rE2-CHIKV e rE2 MAYV ELISAs, particularmente para detecção de IgG, mostraram-se adequadamente sensíveis e específicos para serem validados em estudos com maiores números de amostras e serem aplicados ao diagnóstico de pacientes infectados com CHIKV e MAYV. / Due the existence of 2 arthritogenic alphaviruses in Brasil, the viruses Mayaro (MAYV) and Chikungunya (CHIKV), it became important the development of efficient diagnose tests to discriminate their infections. In the present work, we developed indirect ELISAs for CHIKV and MAYV diagnosis using viral recombinant envelope proteins E2, produced in Escherichia coli, the rE2-CHIKV and rE2-MAYV. The recombinant E2 proteins had their antigenicity confirmed in the assay by using polyclonal antibodies produced in hyperimmunized mice with CHIKV, MAYV and other alphaviruses. The rE2-CHIKV ELISA detected homotypic murine antibodies and did not produced detectable cross-reactivity signal when using murine antibodies from other alphaviruses. The rE2-MAYV ELISA detected homotypic antibodies and also cross-reacted with murine anti-CHIKV antibodies, but not to other alphaviruses. These ELISAs were also tested for the detection of human antibodies, using patient sera suspected of arboviral infection. For rE2- CHIKV ELISA, it were tested 59 sera, resulting in 26 positive IgG samples. These ELISA results, when compared to those of a neutralizing assay, demonstrated a sensibility of 89.66% and specificity of 100%. The IgG positive human sera were detected in high dilutions by rE2-CHIKV ELISA. Regarding the detection of IgM, the rE2-CHIKV ELISA showed a moderate samples detection agreement when compared to other serologic assays. For rE2-MAYV ELISA, it were tested 68 sera, resulting in 23 positive IgG samples, of which 11 demonstrated to be positive by the neutralization assay, demonstrating a sensibility of 100% and specificity of 78.95%. Therefore, the rE2-CHIKV and rE2-MAYV ELISAs, especially for IgG detection, demonstrated to be properly sensitive and specific to be validated in studies using a greater number of samples, and also to be applied in the diagnosis of infected CHIKV and MAYV patients.

La dengue et le chikungunya sont deux arboviroses émergentes qui sont transmises à l'homme par la piqûre de moustiques du genre Aedes. Il n'existe ni vaccin ni traitements commercialisés pour ces arboviroses. Il apparaît donc nécessaire de développer de nouvelles stratégies pour isoler les virus circulants et bloquer leur transmission. La compréhension des mécanismes mis en jeu dans les cellules des vecteurs Aedes lors d'une infection par le virus de la dengue (DENV) sont encore très peu étudiés, notamment pour les sérotypes 1 et 3. Par des analyses protéomiques de l'infection d'une lignée cellulaire du moustique Aedes albopictus par ces séroytypes, nous avons démontré qu'en réponse à l'infection, les cellules de moustiques utilisent les mécanismes antioxydants combinés à la production d'énergie pour faire face au virus. Les résultats de notre étude devraient permettre de mieux comprendre l'interaction DENV-vecteur Aedes au niveau cellulaire dans le but de concevoir des stratégies efficaces pour le contrôle du DENV. Nous avons également regroupé dans une revue les connaissances acquises sur les études protéomiques des principaux compartiments des arthropodes vecteurs de maladies humaines. Dans un second volet, nous avons mis en évidence une méthode rapide d'isolement et de concentration des DENV et du chikungunya. Cette technique d'isolement basée sur la capture de virus sur des billes magnétiques enrobées de polymères anioniques permet d'obtenir des particules virales infectieuses. Cette méthode combinée à des approches classiques de détection de virus pourrait non seulement permettre l'identification des échantillons infectés ayant une faible charge virale, mais aussi l'isolement simultanée de particules infectieuses de dengue et de chikungunya à partir d'un seul échantillon. / Dengue (DENV) and Chikungunya (CHIKV) viruses are two emerging arboviruses that are transmitted to humans by the bite of Aedes sp. mosquito vectors. Neither vaccines, nor medical treatments, are commercially available for these infections. It is, therefore, necessary to elaborate novel strategies to isolate the circulating viruses and block their transmission.Our understanding of the molecular mechanisms involved, during the infection of the Aedes vector by dengue virus (DENV), especially serotypes 1 and 3, remains very scant. We, therefore, performed a proteomics analysis of an Aedes albopictus cell line, infected by these two DENV serotypes, and showed that the cells use both anti-oxidant and energy-production mechanisms in the fight against the virus. These results should help to improve our knowledge of the interaction of the DENV virus and the Aedes mosquito vector, at the cellular level, with the aim of designing efficient strategies for the control of this virus. We have, in addition, developed a rapid and sensitive isolation technique, based on viral particle adsorption to magnetic beads coated with an anionic polymer. The use of this technique is of great interest, as it permits the rapid and simultaneous detection and isolation of CHIKV and DENV from samples with reduced viral loads.

Le virus chikungunya (CHIKV), transmis par les moustiques Aedes aegypti et Aedes albopictus, constitue un problème majeur de santé publique. Depuis 2004, des épidémies de CHIKV ont été rapportées en Afrique, en Asie, dans les îles de l'Océan Indien, et en Europe. Seule l'Amérique semblait épargnée malgré la présence de fortes densités de moustiques vecteurs et de multiples importations du virus dans le continent par des voyageurs de retour de pays où le virus circulait. Nous avons abordé dans cette thèse le risque d'émergence du CHIKV en Amérique à partir d'une évaluation de la compétence vectorielle de 35 populations d'Ae. aegypti et Ae. albopictus locaux avec différentes souches de CHIKV. Ces populations sont compétentes vis-à-vis du CHIKV avec un rôle des glandes salivaires comme "filtre" de la transmission. De plus, le génotypage des Ae. albopictus d'Amérique par microsatellites a permis d'identifier un cluster génétique de populations se caractérisant par une faible transmission des souches de CHIKV de génotype Est-Centre-Sud-africain. En octobre 2013, des souches asiatiques de CHIKV ont été signalées dans la Caraïbe. Nous avons alors évalué la réceptivité de 11 populations d'Ae. aegypti et Ae. albopictus d'Amérique vis-à-vis de CHIKV de génotype asiatique et avons mis en évidence que les deux espèces étaient compétents pour assurer la diffusion du virus sur le continent. On note aussi qu'Ae. albopictus peut faciliter la propagation du CHIKV vers l'Europe. Néanmoins, la compétence vectorielle d'Ae. albopictus de France vis-à-vis de CHIKV asiatique est affectée négativement par des températures plus basses que celles habituellement observées dans les pays tropicaux. / Chikungunya virus (CHIKV), transmitted mainly by the mosquitoes Aedes aegypti and Aedes albopictus, is a major public health problem. Since 2004, CHIKV epidemics have been reported in Africa, Asia, the Indian Ocean Islands, and Europe. Only the Americas seemed spared despite high densities of mosquitoes and multiple introductions of the virus to the continent by travelers returning from countries where CHIKV was circulating. We have assessed the risk of CHIKV emergence in the Americas by evaluating the vector competence of 35 local populations of Ae. aegypti and Ae. albopictus infected with different strains of CHIKV. These populations were shown to be susceptible to CHIKV infection, highlighting the predominant role of salivary glands as a "filter" of transmission. Genotyping of Ae. albopictus from the Americas using microsatellites allowed the identification of a genetic cluster of populations characterized by a low transmission of CHIKV strains of the East-Central-South-African genotype. In October 2013, Asian strains of CHIKV began circulating in the Caribbean. Thus, we evaluated the susceptibility of 11 populations of Ae. aegypti and Ae. albopictus to the Asian CHIKV genotype and showed that the two species were sufficiently competent to ensure dissemination of the virus throughout the continent. Furthermore, we showed that Ae. albopictus was likely to facilitate the spread of CHIKV to Europe. However, the vector competence of French Ae. albopictus to the Asian CHIKV genotype was negatively affected by temperatures lower than those usually found in tropical countries.