Recently introduced Aedes albopictus in Corsica is competent to Chikungunya virus and in a lesser extent to dengue virus

Institut Pasteur, Génétique moléculaire des Bunyavirus, Paris, France.
Tropical Medicine & International Health (Impact Factor: 2.33). 10/2009; 14(9):1105-9. DOI: 10.1111/j.1365-3156.2009.02320.x
Source: PubMed


Aedes albopictus has been established in Europe for some decades rendering temperate countries vulnerable to tropical diseases. The Italian chikungunya (CHIK) outbreak in the summer of 2007 demonstrated that indigenous transmission of CHIK was possible in Europe. To estimate the risk of a CHIK outbreak in Corsica, we assessed the vector competence of A. albopictus established in the island since 2006 towards a CHIK variant (E1-A226V). A dengue serotype 2 virus was also tested. Experimental infections showed that A. albopictus was highly competent to CHIK virus (disseminated infection rates ranging from 75% to 100%) and to a lesser extent, to dengue virus (12.5-68.8%). Moreover, A. albopictus ensured a high level of viral replication and was able to transmit the virus as early as 2 days after ingestion of infected blood with around 1,000 viral RNA available in salivary glands. The risk for a local transmission of CHIK is thus likely in Corsica, if other parameters determining the vector capacity of A. albopictus are suitable.

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    • "Upon its second arrival, A. albopictus became well established in Southern Europe [16,17]. This increases the risk that autochthonous CHIKV transmission may arise, as European populations of A. albopictus exhibit a remarkable high vector competence for CHIKV [18,19]. Indeed, the first epidemic of Chikungunya fever in Europe occurred in Ravenna, Northern Italy, with more than 200 affected humans after virus introduction from India [20]. "
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    ABSTRACT: Chikungunya was, from the European perspective, considered to be a travel-related tropical mosquito-borne disease prior to the first European outbreak in Northern Italy in 2007. This was followed by cases of autochthonous transmission reported in South-eastern France in 2010. Both events occurred after the introduction, establishment and expansion of the Chikungunya-competent and highly invasive disease vector Aedes albopictus (Asian tiger mosquito) in Europe. In order to assess whether these outbreaks are indicative of the beginning of a trend or one-off events, there is a need to further examine the factors driving the potential transmission of Chikungunya in Europe. The climatic suitability, both now and in the future, is an essential starting point for such an analysis. The climatic suitability for Chikungunya outbreaks was determined by using bioclimatic factors that influence both vector and pathogen. Climatic suitability for the European distribution of the vector Aedes albopictus was based upon previous correlative environmental niche models. Climatic risk classes were derived by combining climatic suitability for the vector with known temperature requirements for pathogen transmission, obtained from outbreak regions. In addition, the longest potential intra-annual season for Chikungunya transmission was estimated for regions with expected vector occurrences.In order to analyse spatio-temporal trends for risk exposure and season of transmission in Europe, climate change impacts are projected for three time-frames (2011--2040, 2041--2070 and 2071--2100) and two climate scenarios (A1B and B1) from the Intergovernmental Panel on Climate Change (IPCC). These climatic projections are based on regional climate model COSMO-CLM which builds on the global model ECHAM5. European areas with current and future climatic suitability of Chikungunya transmission are identified. An increase in risk is projected for Western Europe (e.g. France and Benelux-States) in the first half of the 21st century and from mid-century onwards for central parts of Europe (e.g. Germany). Interestingly, the southernmost parts of Europe do not generally provide suitable conditions in these projections. Nevertheless, many Mediterranean regions will persist to be climatically suitable for transmission. Overall, the highest risk of transmission by the end of the 21st century was projected for France, Northern Italy and the Pannonian Basin (East-Central Europe). This general tendency is depicted in both the A1B and B1 climate change scenarios. In order to guide preparedness for further outbreaks, it is crucial to anticipate risk as to identify areas where specific public health measures, such as surveillance and vector control, can be implemented. However, public health practitioners need to be aware that climate is only one factor driving the transmission of vector-borne disease.
    International Journal of Health Geographics 11/2013; 12(1):51. DOI:10.1186/1476-072X-12-51 · 2.62 Impact Factor
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    • "Following infection with DENV-2, disseminated infection rates were roughly similar to values found in previous studies, lower than 50% [16,45-47]. However, disseminated infection rates following exposure to CHIKV were lower than those reported from Corsica [47] and North Italy [16], as those ranged from 75% to 100%. When examining the profile of replication (Figure 4), viral RNA loads were found to peak more rapidly for CHIKV (day 6) than for the other two viruses (day 10 for DENV-2 and day 14 for WNV). "
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    ABSTRACT: Background The mosquito Aedes albopictus is undergoing a worldwide expansion with potential consequences on transmission of various arboviruses. This species has been first detected in Lebanon in 2003. Methods We performed a phylogenetic study of Lebanese specimens and assessed their host preference by detecting human, cat, dog and chicken immunoglobulins in mosquito blood-meals. Their capacity to transmit arboviruses was investigated by providing infectious blood-meals using an artificial feeding system followed by detection of viral particles in mosquito saliva. Results Our results suggest that Lebanese strains are part of the recent wave of Ae. albopictus expansion and are related to some European, African and North American strains. They exhibited a host preference towards humans and an important capacity to transmit arboviruses. Indeed, we showed that Ae. albopictus was able to transmit chikungunya (CHIKV), dengue (DENV) and West-Nile (WNV) viruses. At day 10 after an infectious blood-meal at a titer of 108 MID50/ml, 30% of mosquitoes delivered an average of 515 ± 781 viral particles of CHIKV in saliva collected using a forced salivation technique and 55% with an average of 245 ± 304 viral particles when infected with WNV. Whereas DENV was not found in saliva at day 10 post-infection (pi), an average of 174 ± 455 viral particles was detected in 38.1% of mosquitoes tested at day 21 after an infectious blood-meal at a higher titer of 109 MID50/ml. Conclusion These observations suggest that Ae. albopictus around Beirut is a potential vector of the three tested arboviruses.
    BMC Infectious Diseases 11/2012; 12(1):300. DOI:10.1186/1471-2334-12-300 · 2.61 Impact Factor
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    • "This confirms the ability of the species to deliver early infectious viral particles through saliva (Dubrulle et al., 2009). These results support our previous data on Ae. albopictus (Vazeille et al., 2007, 2008; Moutailler et al., 2009) and demonstrate the likely key role of this species as a vector of CHIKV in the province of Ravenna during the summer of 2007 (Rezza et al., 2007). Among mosquito species usually found in the north of Italy, Ae. vexans exhibited a low susceptibility to CHIKV. "
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    ABSTRACT: The Asian tiger mosquito Aedes albopictus (Skuse) (Diptera: Culicidae), native to Southeast Asia, has extended its geographical distribution to invade new temperate and tropical regions. This species was introduced in 1990 to Italy and has since become the main pest in urban settings. It was incriminated as a principal vector in the first European outbreak of chikungunya virus (CHIKV) in the province of Ravenna (Italy) in 2007. This outbreak was associated with CHIKV E1-226V, efficiently transmitted by Ae. albopictus. The occurrence of this outbreak in a temperate country led us to estimate the potential of Ae. albopictus to transmit CHIKV and dengue virus (DENV), and to determine the susceptibility to CHIKV of other mosquito species collected in northern Italy. Experimental infections showed that Ae. albopictus exhibited high disseminated infection rates for CHIKV (75.0% in Alessandria; 90.3% in San Lazzaro) and low disseminated infection rates for DENV-2 (14.3% in San Lazzaro; 38.5% in Alessandria). Moreover, Ae. albopictus was able to attain a high level of viral replication, with CHIKV detectable in the salivary glands at day 2 after infection. In addition, the other three mosquito species, Anopheles maculipennis Meigen, Aedes vexans vexans (Meigen) and Culex pipiens L., showed variable susceptibilities to infection with CHIKV, of 0%, 7.7% and 0-33%, respectively. This information on vector competence is crucial in assessing the risk for an outbreak of CHIKV or DENV in Italy.
    Medical and Veterinary Entomology 03/2010; 24(1):83-7. DOI:10.1111/j.1365-2915.2009.00853.x · 2.86 Impact Factor
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