Objectifs scientifiques et projet de recherche

Infections caused by Dengue (DENV) and Chikungunya (CHIKV) arboviruses are widespread, medically important arboviral diseases with high socio-economic impact, for which there are no preventive or curative treatments. For both viruses, their main vectors are mosquitoes of the genus Aedes, including Aedes albopictus, originally from Asia, but now present on every continent. DENV is endemic in most urban centers of the tropics and a dramatic increase in urbanization has created ideal conditions for increased transmission of dengue disease. In Thailand, the areas affected by CHIKV overlap those in which dengue fever is endemic and this situation may therefore constitute an increased risk of co-infection by both viruses that are transmitted by the same mosquito vector. Because co-infection of hosts by DENV and CHIKV is likely to be an JEAI program – Application form 2015 3 emerging trend in other parts of the world, the situation in Thailand, where both DENV and CHIKV are endemic, constitutes an interesting model to study its pathophysiological impact. The objectives of the DENCHICTHAI are as follows to constitute cohorts of patients, monoinfected with either DENV (serotype 1, 2, 3 or 4) or CHIKV and co-infected with both viruses, in which the clinical, virological and immunological parameters will be evaluated during the acute, convalescence and post-convalescence phases of infection; I - To determine whether co-infection with both DENV and CHIKV will lead to increased comorbidity and an aggravated clinical state of these patients; II - To isolate DENV and CHIKV from patients’ serum samples and to determine the precise genotype of the viruses that circulate in Thailand thereby establishing its relationship with those of other reported circulating strains; III - To study the consequences of co-infection on mosquito vector competence of both DENV and CHIKV and to determine whether co-infection modulates the immune response of the mosquito vector, as compared with infection of each virus alone; IV - To investigate the dynamics of replication of DENV and CHIKV, either alone or in combination, in permissive human skin cells and to compare the antiviral response between the different experimental conditions of viral infection which might provide a biological explanation if, according to the hypothesis, co-infection results in a more severe clinical state.

Unités IRD impliquées

2R22400 : MIVEGEC

Institutions membres

MU : Mahidol University

Correspondant

Mme. X

Disciplines scientifiques

Biologie, médecine et santé

Thématiques de recherche

The project work will be carried out in collaboration with thirteen hospitals in Thailand. Overall, the results of this study will enable the conclusion whether if patients co-infected by the two arboviruses have an increased risk of developing a severe form of dengue as a result of infection with CHIKV. The data obtained from this project may contribute to better diagnosis and improved medical care for these patients and therefore will be valuable information for public health policy and medical staff. The DENCHICTHAI team will promote capacity building of young scientists, including students from other Asian countries. This project will also strengthen the skills and the partnership between two Thai universities and the UMR 224 MIVEGEC and will provide in-depth knowledge to enrich the training modules in arbovirology and medical entomology that are already in place in the team.