Dengue, Yellow Fever, Zika and Chikungunya epidemic arboviruses in Brazil: ultrastructural aspects

The impact of the cocirculation of several arboviruses in Brazil is still little known. As in the case of reinfection by different serotypes of DENV, the interaction of arboviruses (DENV serotypes 1-4, YF, ZIKV and CHIKV) could theoretically result in more intense viremia or other immunological alterations. In 2015 the epidemic of ZIKV in the Americas provided evidence for features of pathogenicity that had not been previously observed in infections by flaviviruses. ZIKV was shown to be able to cross the placental barrier to cause congenital infections and to be transmitted sexually among humans. In vitro studies by transmission electron microscopy show that part of the ZIKV morphogenesis may occur within viroplasm-like structures never seen in other flaviviruses. Current studies suggest that flaviviruses produce an ensemble of structurally different virions circulating in an organism, collectively contributing to tissue tropism and virus dissemination. In this work, Aedes albopictus mosquito cell lineage (C6/36 cells) and Kidney epithelial cells of African green monkey (Vero cells) were infected with samples of these main circulating arboviruses in Brazil (DENV-1, DENV-2, DENV-3, DENV-4, ZIKV, YF and CHIKV) and ultrastructural studies by transmission electron microscopy were performed.