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The aim of this review was to delve into the extent of mosquito virome coverage (proportion of viral reads) via meta-viromic sequencing and uncover potential factors of heterogeneity that could impact this coverage. Data sources were PubMed, Web of Science, Embase, Scopus, Science-Direct, Google Scholar, and the China National Knowledge Infrastructure. Pooled coverage was estimated using random-effects modeling, and subgroup analyses further reveal potential heterogeneous factors. Within the three mosquito genera studied, Culex exhibited the highest pooled viral coverage of mosquito viromes at 7.09% (95% CI: 3.44–11.91%), followed by Anopheles at 5.28% (95% CI: 0.45–14.93%), and Aedes at 2.11% (95% CI: 0.58–7.66%). Subgroup analyses showed that multiple processing methods significantly affected the viral coverage of mosquito viromes, especially pre-treatment of mosquito samples with saline buffer/medium and antibiotics prior to DNase/RNase treatment and removal of the host genome prior to RNA library construction. In conclusion, the results of this study demonstrate that the viral coverage of mosquito viromes varies between mosquito genera and that pre-treatment of mosquito samples with saline buffer/medium and antibiotics before DNase/RNase treatment and removing host genomes prior to RNA library construction are critical for the detection of RNA viruses in mosquito vectors using meta-viromic sequencing.

The most prevalent arthropod-borne viruses, including the dengue viruses, are primarily transmitted by infected mosquitoes. However, the dynamics of dengue virus (DENV) infection and dissemination in human skin following Aedes aegypti probing remain poorly understood. We exposed human skin explants to adult female Ae. aegypti mosquitoes following their infection with DENV-2 by intrathoracic injection. Skin explants inoculated with a similar quantity of DENV-2 by a bifurcated needle were used as controls. Quantitative in situ imaging revealed that DENV replication was greatest in keratinocytes in the base of the epidermis, accounting for 50–60% of all infected cells regardless of the route of inoculation. However, DENV inoculation by Ae. aegypti probing resulted in an earlier and increased viral replication in the dermis, infecting twice as many cells at 24 h when compared to needle inoculation. Within the dermis, enhanced replication of DENV by Ae. aegypti infected mosquitoes was mediated by increased local recruitment of skin-resident macrophages, dermal dendritic cells, and epidermal Langerhans cells relative to needle inoculation. An enhanced but less pronounced influx of resident myeloid cells to the site of mosquito probing was also observed in the absence of infection. Ae. aegypti probing also increased recruitment and infection of dermal mast cells. Our findings reveal for the first time that keratinocytes are the primary targets of DENV infection following Ae. aegypti inoculation, even though most of the virus is inoculated into the dermis during probing. The data also show that mosquito probing promotes the local recruitment and infection of skin-resident myeloid cells in the absence of an intact vasculature, indicating that influx of blood-derived neutrophils is not an essential requirement for DENV spread within and out of skin.

The complete lack of yellow fever virus (YFV) in Asia, and the lack of urban YFV transmission in South America, despite the abundance of the peridomestic mosquito vector Aedes (Stegomyia.) aegypti is an enigma. An immunologically naïve population of over 2 billion resides in Asia, with most regions infested with the urban YF vector. One hypothesis for the lack of Asian YF, and absence of urban YF in the Americas for over 80 years, is that prior immunity to related flaviviruses like dengue (DENV) or Zika virus (ZIKV) modulates YFV infection and transmission dynamics. Here we utilized an interferon α/β receptor knock-out mouse model to determine the role of pre-existing dengue-2 (DENV-2) and Zika virus (ZIKV) immunity in YF virus infection, and to determine mechanisms of cross-protection. We utilized African and Brazilian YF strains and found that DENV-2 and ZIKV immunity significantly suppresses YFV viremia in mice, but may or may not protect relative to disease outcomes. Cross-protection appears to be mediated mainly by humoral immune responses. These studies underscore the importance of re-assessing the risks associated with YF outbreak while accounting for prior immunity from flaviviruses that are endemic.

In this study, we analyzed the potential of viral infections in the species Homo sapiens as environmental causes of orofacial clefts (OFCs). A scoring system was adapted for qualitatively assessing the potential of viruses to cause cleft lip and/or palate (CL/P). This assessment considered factors such as information from the literature, nucleotide and amino acid similarities, and the presence of Endogenous Viral Elements (EVEs). The analysis involved various algorithm packages within Basic Local Alignment Search Tool 2.13.0 software and databases from the National Center for Biotechnology Information and the International Committee on Taxonomy of Viruses. Twenty significant viral species using different biosynthesis strategies were identified: Human coronavirus NL63, Rio Negro virus, Alphatorquevirus homin9, Brisavirus, Cosavirus B, Torque teno mini virus 4, Bocaparvovirus primate2, Human coronavirus HKU1, Monkeypox virus, Mammarenavirus machupoense, Volepox virus, Souris mammarenavirus, Gammapapillomavirus 7, Betainfluenzavirus influenzae, Lymphocytic choriomeningitis mammarenavirus, Ledantevirus kern, Gammainfluenzavirus influenzae, Betapolyomavirus hominis, Vesiculovirus perinet, and Cytomegalovirus humanbeta5. The evident viral etiological potential in relation to CL/P varies depending on the Baltimore class to which the viral species belongs. Given the multifactorial nature of CL/P, this relationship appears to be dynamic.

Background and Objectives: Mosquito-borne viral diseases (MBVDs) create a dramatic health situation worldwide. There is a need to improve the understanding of factors to be addressed in intervention programmes. This study explored community knowledge, attitudes, and practices (KAP) regarding MBVD in Kinshasa. Materials and Methods: A cross-sectional survey was carried out between January and April 2019. The socio-demographic and KAP data collected through a questionnaire were analysed using Epi Info 7. Results: The study included 1464 male and female respondents aged from 18 to 70 years old. Open garbage cans and outdoor water storage units were found in 61.2% and 33.4% of respondent residences, respectively. Polluted water bodies (80.3%) were the most mentioned as mosquito breeding places. Among 86.6% of the respondents that had heard about yellow fever, 12% knew that it is an MBVD. The majority of respondents (72.5%) were perceived to be at risk of contracting MBVD. Environment sanitation (58%) and insecticide use (25%) were among the measures implemented to control mosquitoes. The greater overall knowledge score and attitude were not associated with good practice. Conclusion: The residents of Kinshasa had limited knowledge of MBVD. Raising awareness and educational sessions are essential in empowering the community regarding the correct attitudes and practices to effectively manage the risk posed by MBVD.

Due to globalisation and climate change, mosquito-borne pathogens are emerging in new areas on all continents, including Europe, which has recently faced outbreaks of dengue, chikungunya and West Nile fever. The present study complements previous investigations to evaluate the circulation of mosquito-borne viruses in Germany, with the aim of identifying potential vector species and risk areas. Mosquitoes collected from 2019 to 2021 and identified to species or species group level were screened for viruses of the families Flaviviridae, Peribunyaviridae and the genus Alphavirus of the family Togaviridae. In total, 22,528 mosquitoes were examined, thus providing the most comprehensive study on West Nile virus (WNV) circulation so far in the German mosquito population. Usutu virus (USUV) RNA was detected in six samples, Sindbis virus (SINV) RNA in 21 samples and WNV RNA in 11 samples. Samples containing RNA of USUV and WNV consisted of mosquitoes collected in the East German federal states of Brandenburg, Saxony and Saxony-Anhalt, while samples with RNA of SINV originated from more widespread locations. Although minimum infection rates have remained relatively low, the intensity of virus circulation appears to be increasing compared to previous studies. Continuous mosquito screening contributes to the early detection of the introduction and spread of mosquito-borne pathogens.

The aim of this review was to delve into the extent of mosquito virome coverage (proportion of viral reads) via meta-viromic sequencing and uncover potential factors of heterogeneity that could impact this coverage. Data sources were PubMed, Web of Science, Embase, Scopus, Science-Direct, Google Scholar, and the China National Knowledge Infrastructure. Pooled coverage was estimated using random-effects modeling, and subgroup analyses further reveal potential heterogeneous factors. Within the three mosquito genera studied, Culex exhibited the highest pooled viral coverage of mosquito viromes at 7.09% (95% CI: 3.44-11.91%), followed by Anopheles at 5.28% (95% CI: 0.45-14.93%), and Aedes at 2.11% (95% CI: 0.58-7.66%). Subgroup analyses showed that multiple processing methods significantly affected the viral coverage of mosquito viromes, especially pre-treatment of mosquito samples with saline buffer/medium and antibiotics prior to DNase/RNase treatment and removal of the host genome prior to RNA library construction. In conclusion, the results of this study demonstrate that the viral coverage of mosquito viromes varies between mosquito genera and that pre-treatment of mosquito samples with saline buffer/medium and antibiotics before DNase/RNase treatment and removing host genomes prior to RNA library construction are critical for the detection of RNA viruses in mosquito vectors using meta-viromic sequencing.

Among emerging zoonotic pathogens, mosquito-borne viruses (MBVs) circulate between vertebrate animals and mosquitoes and represent a serious threat to humans via spillover from enzootic cycles to the human community. Active surveillance of MBVs in their vectors is therefore essential to better understand and prevent spillover and emergence, especially at the human–animal interface. In this study, we assessed the presence of MBVs using molecular and phylogenetic methods in mosquitoes collected along an ecological gradient ranging from rural urbanized areas to highland forest areas in northern Thailand. We have detected the presence of insect specific flaviviruses in our samples, and the presence of the emerging zoonotic Tembusu virus (TMUV). Reported for the first time in 1955 in Malaysia, TMUV remained for a long time in the shadow of other flaviviruses such as dengue virus or the Japanese encephalitis virus. In this study, we identified two new TMUV strains belonging to cluster 3, which seems to be endemic in rural areas of Thailand and highlighted the genetic specificities of this Thai cluster. Our results show the active circulation of this emerging flavivirus in Thailand and the need for continuous investigation on this poorly known but threatening virus in Asia.

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.

Rift Valley fever virus (RVFV) is a zoonotic phlebovirus of the Phenuiviridae family with great opportunity for emergence in previously unaffected regions, despite its current geographical limits. Outbreaks of RVFV often infect humans or domesticated animals, such as livestock, concurrently and occur sporadically, ranging from localized outbreaks in villages to multi-country events that spread rapidly. The true burden of Rift Valley fever (RVF) is not well defined due to underreporting, misdiagnosis caused by the broad spectrum of disease presentation, and minimal access for rapid and accurate laboratory confirmation. Severe symptoms may include hemorrhagic fever, loss of vision, psychological impairment or disturbances, and organ failure. Those living in endemic areas and travelers should be aware of the potential for exposure to ongoing outbreaks or interepidemic transmission, and engage in behaviors to minimize exposure risks, as vaccinations in humans are currently unavailable and animal vaccinations are not used routinely or ubiquitously. The lack of vaccines approved for use in humans is concerning, as RVFV has proven to be highly pathogenic in naïve populations, causing severe disease in a large percent of confirmed cases, which could have considerable impact on human health.

The risk of emergence and/or re-emergence of arthropod-borne viral (arboviral) infections is rapidly growing worldwide, particularly in Africa. The burden of arboviral infections and diseases is not well scrutinized because of the inefficient surveillance systems in endemic countries. Furthermore, the health systems are fully occupied by the burden of other co-existing febrile illnesses, especially malaria. In this review we summarize the epidemiology and risk factors associated with the major human arboviral diseases and highlight the gap in knowledge, research, and control in Sudan. Published data in English up to March 2019 were reviewed and are discussed to identify the risks and challenges for the control of arboviruses in the country. In addition, the lack of suitable diagnostic tools such as viral genome sequencing, and the urgent need for establishing a genomic database of the circulating viruses and potential sources of entry are discussed. Moreover, the research and healthcare gaps and global health threats are analyzed, and suggestions for developing strategic health policy for the prevention and control of arboviruses with focus on building the local diagnostic and research capacity and establishing an early warning surveillance system for the early detection and containment of arboviral epidemics are offered.

Mosquitoes are vectors of arboviruses affecting animal and human health. Arboviruses circulate primarily within an enzootic cycle and recurrent spillovers contribute to the emergence of human-adapted viruses able to initiate an urban cycle involving anthropophilic mosquitoes. The increasing volume of travel and trade offers multiple opportunities for arbovirus introduction in new regions. This scenario has been exemplified recently with the Zika pandemic. To incriminate a mosquito as vector of a pathogen, several criteria are required such as the detection of natural infections in mosquitoes. In this study, we used a high-throughput chip based on the BioMark™ Dynamic arrays system capable of detecting 64 arboviruses in a single experiment. A total of 17,958 mosquitoes collected in Zika-endemic/epidemic countries (Brazil, French Guiana, Guadeloupe, Suriname, Senegal, and Cambodia) were analyzed. Here we show that this new tool can detect endemic and epidemic viruses in different mosquito species in an epidemic context. Thus, this fast and low-cost method can be suggested as a novel epidemiological surveillance tool to identify circulating arboviruses.

Rift Valley fever virus (RVFV) is a zoonotic phlebovirus of the Phenuiviridae family with great opportunity for emergence in previously unaffected regions, despite its current geographical limits. Outbreaks of RVFV often infect humans or domesticated animals, such as livestock, concurrently and occur sporadically, ranging from localized outbreaks in villages to multi-country events that spread rapidly. The true burden of Rift Valley fever (RVF) is not well defined due to underreporting, misdiagnosis caused by the broad spectrum of disease presentation, and minimal access for rapid and accurate laboratory confirmation. Severe symptoms may include hemorrhagic fever, loss of vision, psychological impairment or disturbances, and organ failure. Those living in endemic areas and travelers should be aware of the potential for exposure to ongoing outbreaks or interepidemic transmission, and engage in behaviors to minimize exposure risks, as vaccinations in humans are currently unavailable and animal vaccinations are not used routinely or ubiquitously. The lack of vaccines approved for use in humans is concerning, as RVFV has proven to be highly pathogenic in naïve populations, causing severe disease in a large percent of confirmed cases, which could have considerable impact on human health.