Prevention and control of the infectious risk of contemporary African strains of the Zika virus
The project concerns the Zika virus, which causes severe congenital malformations. Its aim is to characterize the factors promoting the pathogen's transmission by mosquitoes and viral persistence in individuals. The objective is to propose innovative anti-infective strategies based on the antiviral action of compounds extracted from plants in the overseas territory.
The Zika virus (ZIKV) is an arbovirus transmitted to humans by mosquitoes of the Aedes genus. ZIKV became a major public health problem starting in 2013 with epidemics in French Polynesia and then in Latin America. ZIKV epidemics have been associated so far with pathogenic viral strains originating from Asia. Viral infection in pregnant women can lead to major teratogenic effects grouped under the term Congenital Zika Syndrome (CZS), resulting in microcephaly and other congenital malformations in newborns. In infected adults, ZIKV is found in body fluids such as ocular secretions, urine, and especially semen. Human-to-human transmission of ZIKV via sexual intercourse has been unequivocally demonstrated during the 2015-2016 epidemic, linked to viral persistence in the male reproductive system. The risk of CZS remains poorly documented in Africa where ZIKV strains of the African genotype are distinct from the Asian genotype. ZIKV strains isolated recently in West Africa have a high teratogenic potential and are more efficiently transmitted by Ae. aegypti mosquitoes than Asian strains. The tiger mosquito vector Ae. albopictus has spread to Europe, including France, and also to overseas territories including Reunion Island (Indian Ocean). African strains of ZIKV represent an emergence risk in regions, including temperate ones, where Ae. albopictus has spread.
The CAZIKANO project, which involves eight multidisciplinary teams in France and Australia under the coordination of the UMR PIMIT in Reunion, aims to assess the emergence risk of the African genotype of ZIKV through the integrative study of two contemporary viral strains, one from a mosquito pool collected in Senegal in 2011 and the other from an infected individual in Guinea in 2018. The two viruses will be characterized for (i) their transmission efficiency by vector mosquitoes and their ability to cross the intestinal barrier of insects (Aedes mosquitoes and Drosophila model), (ii) their efficiency in replicating and persisting in target human cells related to the pathogenesis of viral infection, and (iii) their sensitivity to natural substances to identify inhibitors of viral replication. The CAZIKANO project will provide important information on the risk of vector and non-vector propagation of contemporary African strains of ZIKV, with the prospect of rationalizing the development of effective antiviral compound analogs from natural substances.
