Excretion of dengue virus RNA by Aedes aegypti allows non-destructive monitoring of viral dissemination in individual mosquitoes

Albin Fontaine (1, 2) , Davy Jiolle (1) , Isabelle Moltini-Conclois (1) , Sebastian Lequime (1, 3) , Louis Lambrechts (1)

1 IVI - Interactions Virus-Insectes
2 Equipe Résidente de Recherche en Infectiologie Tropicale
3 UPMC - Université Pierre et Marie Curie - Paris 6 - UFR de Médecine Pierre et Marie Curie

Successful transmission of a vector-borne pathogen relies on a complex life cycle in the arthropod vector that requires initial infection of the digestive tract followed by systemic viral dissemination. The time interval between acquisition and subsequent transmission of the pathogen, called the extrinsic incubation period, is one of the most influential parameters of vector-borne pathogen transmission. However, the dynamic nature of this process is often ignored because vector competence assays are sacrificial and rely on end-point measurements. Here, we report that individual Aedes aegypti mosquitoes release large amounts of dengue virus (DENV) RNA in their excreta that can be non-sacrificially detected over time following oral virus exposure. Further, we demonstrate that detection of DENV RNA in excreta from individual mosquitoes is correlated to systemic viral dissemination with high specificity (0.9–1) albeit moderate sensitivity (0.64–0.89). Finally, we illustrate the potential of our finding to detect biological differences in the dynamics of DENV dissemination in a proof-of-concept experiment. Individual measurements of the time required for systemic viral dissemination, a prerequisite for transmission, will be valuable to monitor the dynamics of DENV vector competence, to carry out quantitative genetics studies, and to evaluate the risk of DENV transmission in field settings. Vector competence is the intrinsic ability of arthropods to acquire and subsequently transmit vector-borne pathogens , such as, malaria parasites or dengue viruses (DENV) 1. Experimental vector competence assessments of arthropod populations are an important component of assessing the risk of vector-borne disease. Vector competence is a quantitative trait that varies not only between arthropod species, but also within a vector species. For example, 24 populations of the mosquito Aedes aegypti sampled throughout Mexico and the United States displayed substantial variation in their vector competence for DENV 2

Domains: Life Sciences [q-bio]; Human health and pathology; Emerging diseases

Albin Fontaine, Davy Jiolle, Isabelle Moltini-Conclois, Sebastian Lequime, Louis Lambrechts. Excretion of dengue virus RNA by Aedes aegypti allows non-destructive monitoring of viral dissemination in individual mosquitoes. Scientific Reports, 2016, 6, ⟨10.1038/srep24885⟩. ⟨pasteur-01316118⟩