Mosquito-Specific Viruses-Transmission and Interaction

Abstract

Mosquito-specific viruses (MSVs) are a subset of insect-specific viruses that are found to infect mosquitoes or mosquito derived cells. There has been an increase in discoveries of novel MSVs in recent years. This has expanded our understanding of viral diversity and evolution but has also sparked questions concerning the transmission of these viruses and interactions with their hosts and its microbiome. In fact, there is already evidence that MSVs interact with the immune system of their host. This is especially interesting, since mosquitoes can be infected with both MSVs and arthropod-borne (arbo) viruses of public health concern. In this review, we give an update on the different MSVs discovered so far and describe current data on their transmission and interaction with the mosquito immune system as well as the effect MSVs could have on an arboviruses-co-infection. Lastly, we discuss potential uses of these viruses, including vector and transmission control.

Keywords: MSV; RNAi; arbovirus; horizontal transmission; vaccines; vector control; vertical transmission.

Figure 1

Potential transmission routes for MSVs: It is hypothesized that MSVs can be transmitted horizontally from environment to the adults through feeding on plant nectars (A) or to the larvae from plant material in the water or directly through the water (B). Infected larvae and adults might become natural reservoir for some MSVs when they die (e.g. food source) (C). The larvae that survive the infection can emerge as adults and potentially vertically transmit MSVs to their offspring either directly through the egg (transovarially) or indirectly by contaminating the egg surface (transovum) or the water (D). Some MSVs have been shown to be horizontally transmitted by parasitic mermithids, where the latter carries the MSV when they enter the larvae (E). MSVs can also be venereally transmitted between infected and uninfected adults in a low rate (F).