Chikungunya virus and Aedes mosquitoes: saliva is infectious as soon as two days after oral infection.

Mathieu Dubrulle (1) , Laurence Mousson (1) , Sara Moutailler (1) , Marie Vazeille (1) , Anna-Bella Failloux (1)

1 Génétique Moléculaire des Bunyavirus

BACKGROUND: Aedes aegypti and Aedes albopictus are potential vectors of chikungunya virus (CHIKV). The recent CHIKV outbreaks were caused by a new variant characterized by a mutation in the E1 glycoprotein gene (E1-226V) which has favored a better transmissibility by Ae. albopictus. As Ae. albopictus tends to replace Ae. aegypti in many regions, one question remained: is Ae. albopictus as efficient as Ae. aegypti to transmit the variant E1-226V of CHIKV? METHODOLOGY AND FINDINGS: We infected orally both species with the variant E1-226V and estimated the infection, the viral dissemination, and the transmission rate by real time RT-PCR. Additionally, we used an in vitro assay to determine the amount of virus delivered by mosquitoes in their saliva. We found that Ae. aegypti as well as Ae. albopictus ensured a high replication of the virus which underwent an efficient dissemination as detectable in the salivary glands at day 2 post-infection (pi). Infectious CHIKV particles were delivered by salivary glands from day 2 with a maximum at day 6 pi for Ae. albopictus (10(3.3) PFU) and day 7 pi for Ae. aegypti (10(2.5) PFU). CONCLUSIONS: Ae. albopictus is slightly more efficient than Ae. aegypti to transmit the variant E1-226V of CHIKV. These results will help to design an efficient vector control to limit transmission as soon as the first human cases are diagnosed.

Keywords: Aedes; chikungunya; saliva; transmission

Domains: Symbiosis

Mathieu Dubrulle, Laurence Mousson, Sara Moutailler, Marie Vazeille, Anna-Bella Failloux. Chikungunya virus and Aedes mosquitoes: saliva is infectious as soon as two days after oral infection.: Salivation and CHIKV. PLoS ONE, 2009, 4 (6), pp.e5895. ⟨10.1371/journal.pone.0005895⟩. ⟨pasteur-00395262⟩