Impact of Espirito Santo Virus on Dengue Virus Growth Kinetics In Vitro

Abstract

With more than half the world’s population living in areas at risk, vector-borne diseases have been, and continue to be, a major threat to public health. One of the most important arboviruses today is dengue virus (DENV) which impacts approximately 390 million individuals each year. Dengue virus is transmitted primarily by Aedes aegypti and Ae. albopictus mosquitoes, which are now prevalent in just about every continent across the globe due to urbanization and climate change. Co-circulation of vectors capable of transmitting various pathogens put humans at risk for contracting one or more arboviruses either simultaneously or sequentially. Espirito Santo virus (ESV) has been characterized as an insect-specific virus (i.e., should not replicate or have cytopathic effects in mammalian cells). Here, we investigated ESV growth kinetics in various mammalian cell lines and evaluated the interaction between ESV and DENV in coinfection. We hypothesized that ESV would interfere with DENV replication in vitro. We show that ESV replicated in human embryonic kidney (HEK) cells without the presence of DENV, indicating that the virus may not be insect-specific. We also found that ESV seemed to inhibit the growth of DENV in Vero cells. However, DENV seemed to inhibit ESV growth in all cell lines. Although our findings did not support our initial hypothesis, we expect our findings will lead to further studies evaluating ESV alone and ESV coinfection with other medically important arboviruses and under different initial infecting doses. This could further discoveries in combating the global burden of arboviral diseases.