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.

BackgroundThe prevalence of transfusion associated hepatitis B virus infection varies across different geographical populations. Establishing the sero-prevalence of the disease is important to informing the direction of preventive and control strategies. We sought to estimate the sero-prevalence of hepatitis B surface antigen among blood donors in Ho Municipal Hospital, Ghana.MethodsThis was a retrospective study which involved reviewing of blood donation records for the year 2014 in Ho Municipal Hospital. The records were analysed to determine the prevalence of hepatitis B virus among blood donors. Data analysis was done using STATA statistical package.ResultsA total of 576 blood donors were screened in 2014, out of which 520 (90%) were males and the rest females. The overall sero-prevalence of hepatitis B virus was 7.5% (95% CI 5.6–9.9%). The prevalence was highest (8.9%; 95% CI 5.6–14.0) among donors between 30 and 39 years old and among females (14.3%; 95% CI 7.4–25.7). Females were about 2.5 times more likely to be HBsAg positive compared with males (p < 0.05).ConclusionsThe findings suggest that the study region is of intermediate to high endemicity with hepatitis B infection. Generally, females are more likely to be HBsAg positive than males. Planning more extensive screening and vaccination campaigns and educational programmes would help reduce the transmission of the infection among the general population.

Mosquito-associated viruses (MAVs), including mosquito-specific viruses (MSVs) and mosquito-borne (arbo)viruses (MBVs), are an increasing public, veterinary, and global health concern, and West Africa is projected to be the next front for arboviral diseases. As in-depth knowledge of the ecologies of both western African MAVs and related mosquitoes is still limited, we review available and comprehensive data on their diversity, abundance, and distribution. Data on MAVs’ occurrence and related mosquitoes were extracted from peer-reviewed publications. Data on MSVs, and mosquito and vertebrate host ranges are sparse. However, more data are available on MBVs (i.e., dengue, yellow fever, chikungunya, Zika, and Rift Valley fever viruses), detected in wild and domestic animals, and humans, with infections more concentrated in urban areas and areas affected by strong anthropogenic changes. Aedes aegypti, Culex quinquefasciatus, and Aedes albopictus are incriminated as key arbovirus vectors. These findings outline MAV, related mosquitoes, key knowledge gaps, and future research areas. Additionally, these data highlight the need to increase our understanding of MAVs and their impact on host mosquito ecology, to improve our knowledge of arbovirus transmission, and to develop specific strategies and capacities for arboviral disease surveillance, diagnostic, prevention, control, and outbreak responses in West Africa.