| 1. |
- Blagrove, Marcus S. C., et al.
(författare)
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Potential for Zika virus transmission by mosquitoes in temperate climates
- 2020
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 287:1930
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Tidskriftsartikel (refereegranskat)abstract
- Mosquito-borne Zika virus (ZIKV) transmission has almost exclusively been detected in the tropics despite the distributions of its primary vectors extending farther into temperate regions. Therefore, it is unknown whether ZIKV's range has reached a temperature-dependent limit, or if it can spread into temperate climates. Using field-collected mosquitoes for biological relevance, we found that two common temperate mosquito species,Aedes albopictusandOchlerotatus detritus, were competent for ZIKV. We orally exposed mosquitoes to ZIKV and held them at between 17 and 31 degrees C, estimated the time required for mosquitoes to become infectious, and applied these data to a ZIKV spatial risk model. We identified a minimum temperature threshold for the transmission of ZIKV by mosquitoes between 17 and 19 degrees C. Using these data, we generated standardized basic reproduction numberR(0)-based risk maps and we derived estimates for the length of the transmission season for recent and future climate conditions. Our standardizedR(0)-based risk maps show potential risk of ZIKV transmission beyond the current observed range in southern USA, southern China and southern European countries. Transmission risk is simulated to increase over southern and Eastern Europe, northern USA and temperate regions of Asia (northern China, southern Japan) in future climate scenarios.
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| 2. |
- Caminade, Cyril, et al.
(författare)
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Global risk model for vector-borne transmission of Zika virus reveals the role of El Nino 2015
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:1, s. 119-124
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Tidskriftsartikel (refereegranskat)abstract
- Zika, a mosquito-borne viral disease that emerged in South America in 2015, was declared a Public Health Emergency of International Concern by the WHO in February of 2016. We developed a climate-driven R-0 mathematical model for the transmission risk of Zika virus (ZIKV) that explicitly includes two keymosquito vector species: Aedes aegypti and Aedes albopictus. The model was parameterized and calibrated using the most up to date information from the available literature. It was then driven by observed gridded temperature and rainfall datasets for the period 1950-2015. We find that the transmission risk in South America in 2015 was the highest since 1950. This maximum is related to favoring temperature conditions that caused the simulated biting rates to be largest and mosquito mortality rates and extrinsic incubation periods to be smallest in 2015. This event followed the suspected introduction of ZIKV in Brazil in 2013. The ZIKV outbreak in Latin America has very likely been fueled by the 2015-2016 El Nino climate phenomenon affecting the region. The highest transmission risk globally is in South America and tropical countries where Ae. aegypti is abundant. Transmission risk is strongly seasonal in temperate regions where Ae. albopictus is present, with significant risk of ZIKV transmission in the southeastern states of the United States, in southern China, and to a lesser extent, over southern Europe during the boreal summer season.
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| 3. |
- Hesson, Jenny C., et al.
(författare)
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Culex torrentium Mosquito Role as Major Enzootic Vector Defined by Rate of Sindbis Virus Infection, Sweden, 2009
- 2015
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 21:5, s. 875-878
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Tidskriftsartikel (refereegranskat)abstract
- We isolated Sindbis virus (SINV) from the enzootic mosquito vectors Culex torrentium, Cx. pipiens, and Culiseta morsitans collected in an area of Sweden where SINV disease is endemic. The infection rate in Cx. torrentium mosquitoes was exceptionally high (36 infections/1,000 mosquitoes), defining Cx. torrentium as the main enzootic vector of SINV in Scandinavia.
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| 4. |
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| 5. |
- Ling, Jiaxin, et al.
(författare)
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Identification of hepatitis C virus in the common bed bug - a potential, but uncommon route for HCV infection?
- 2020
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Ingår i: Emerging Microbes & Infections. - : TAYLOR & FRANCIS LTD. - 2222-1751. ; 9:1, s. 1429-1431
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Tidskriftsartikel (refereegranskat)abstract
- During an ongoing virome metagenomics project we identified hepatitis C virus (HCV) in a pool of recently blood-fed common bed bug (Cimex lectularius) nymphs sampled from domestic residences in Europe. Additional PCR and genomic analysis revealed that the virus was a member of HCV genotype 3A, one of the most prevalent genotypes in Europe. Although the role of the common bed bug in the transmission of human hepatitis viruses remains unclear, our study suggests that it merits additional investigation.
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| 6. |
- Ortiz-Baez, Ayda Susana, et al.
(författare)
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Meta-transcriptomics reveals potential virus transfer between Aedes communis mosquitoes and their parasitic water mites
- 2022
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Ingår i: Virus Evolution. - : Oxford University Press. - 2057-1577. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Arthropods harbor a largely undocumented diversity of RNA viruses. Some arthropods, like mosquitoes, can transmit viruses to vertebrates but are themselves parasitized by other arthropod species, such as mites. Very little is known about the viruses of these ectoparasites and how they move through the host-parasite relationship. To address this, we determined the virome of both mosquitoes and the mites that feed on them. The mosquito Aedes communis is an abundant and widely distributed species in Sweden, in northern Europe. These dipterans are commonly parasitized by water mite larvae (Trombidiformes: Mideopsidae) that are hypothesized to impose negative selection pressures on the mosquito by reducing fitness. In turn, viruses are dual-host agents in the mosquito-mite interaction. We determined the RNA virus diversity of mite-free and mite-detached mosquitoes, as well as their parasitic mites, using meta-transcriptomic sequencing. Our results revealed an extensive RNA virus diversity in both mites and mosquitoes, including thirty-seven putative novel RNA viruses that cover a wide taxonomic range. Notably, a high proportion of viruses (20/37) were shared between mites and mosquitoes, while a limited number of viruses were present in a single host. Comparisons of virus composition and abundance suggest potential virus transfer between mosquitoes and mites during their symbiotic interaction. These findings shed light on virome diversity and ecology in the context of arthropod host-parasite-virus relationships.
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| 7. |
- Parry, Rhys, et al.
(författare)
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Identification and RNAi Profile of a Novel Iflavirus Infecting Senegalese Aedes vexans arabiensis Mosquitoes
- 2020
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- The inland floodwater mosquito Aedes vexans (Meigen, 1830) is a competent vector of numerous arthropod-borne viruses such as Rift Valley fever virus (Phenuiviridae) and Zika virus (Flaviviridae). Aedes vexans spp. have widespread Afrotropical distribution and are common European cosmopolitan mosquitoes. We examined the virome of Ae. vexans arabiensis samples from Barkedji village, Senegal, with small RNA sequencing, bioinformatic analysis, and RT-PCR screening. We identified a novel 9494 nt iflavirus (Picornaviridae) designated here as Aedes vexans iflavirus (AvIFV). Annotation of the AvIFV genome reveals a 2782 amino acid polyprotein with iflavirus protein domain architecture and typical iflavirus 5' internal ribosomal entry site and 3' poly-A tail. Aedes vexans iflavirus is most closely related to a partial virus sequence from Venturia canescens (a parasitoid wasp) with 56.77% pairwise amino acid identity. Analysis of AvIFV-derived small RNAs suggests that AvIFV is targeted by the exogenous RNA interference pathway but not the PIWI-interacting RNA response, as similar to 60% of AvIFV reads corresponded to 21 nt Dicer-2 virus-derived small RNAs and the 24-29 nt AvIFV read population did not exhibit a "ping-pong" signature. The RT-PCR screens of archival and current (circa 2011-2020) Ae. vexans arabiensis laboratory samples and wild-caught mosquitoes from Barkedji suggest that AvIFV is ubiquitous in these mosquitoes. Further, we screened wild-caught European Ae. vexans samples from Germany, the United Kingdom, Italy, and Sweden, all of which tested negative for AvIFV RNA. This report provides insight into the diversity of commensal Aedes viruses and the host RNAi response towards iflaviruses.
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| 8. |
- Pettersson, John H-O, 1981-, et al.
(författare)
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Meta-Transcriptomic Comparison of the RNA Viromes of the Mosquito Vectors Culex pipiens and Culex torrentium in Northern Europe
- 2019
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 11:11
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Tidskriftsartikel (refereegranskat)abstract
- Mosquitoes harbor an extensive diversity of 'insect-specific' RNA viruses in addition to those important to human and animal health. However, because most studies of the mosquito virome have been conducted at lower latitudes, little is known about the diversity and evolutionary history of RNA viruses sampled from mosquitoes in northerly regions. Here, we compared the RNA virome of two common northern mosquito species, Culex pipiens and Culex torrentium, collected in south-central Sweden. Following bulk RNA-sequencing (meta-transcriptomics) of 12 libraries, comprising 120 specimens of Cx. pipiens and 150 specimens of Cx. torrentium, we identified 40 viruses (representing 14 virus families) of which 28 were novel based on phylogenetic analysis of the RNA-dependent RNA polymerase (RdRp) protein. Hence, we documented similar levels of virome diversity as in mosquitoes sampled from the more biodiverse lower latitudes. Many viruses were also related to those sampled on other continents, indicative of a widespread global movement and/or long host-virus co-evolution. Although the two mosquito species investigated have overlapping geographical distributions and share many viruses, several viruses were only found at a specific location at this scale of sampling, such that local habitat and geography may play an important role in shaping viral diversity in Culex mosquitoes.
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| 9. |
- Bergman, Alexander, et al.
(författare)
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Sindbis Virus Infection in Non-Blood-Fed Hibernating Culex pipiens Mosquitoes in Sweden
- 2020
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Ingår i: Viruses. - : MDPI AG. - 1999-4915. ; 12:12
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Tidskriftsartikel (refereegranskat)abstract
- A crucial, but unresolved question concerning mosquito-borne virus transmission is how these viruses can remain endemic in regions where the transmission is halted for long periods of time, due to mosquito inactivity in, e.g., winter. In northern Europe, Sindbis virus (SINV) (genus alphavirus, Togaviridae) is transmitted among birds by Culex mosquitoes during the summer, with occasional symptomatic infections occurring in humans. In winter 2018-19, we sampled hibernating Culex spp females in a SINV endemic region in Sweden and assessed them individually for SINV infection status, blood-feeding status, and species. The results showed that 35 out of the 767 collected mosquitoes were infected by SINV, i.e., an infection rate of 4.6%. The vast majority of the collected mosquitoes had not previously blood-fed (98.4%) and were of the species Cx. pipiens (99.5%). This is the first study of SINV overwintering, and it concludes that SINV can be commonly found in the hibernating Cx. pipiens population in an endemic region in Sweden, and that these mosquitoes become infected through other means besides blood-feeding. Further studies on mosquito ecology and viral interactions are needed to elucidate the mechanisms of the persistence of these viruses over winter.
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| 10. |
- Bergman, Alexander, et al.
(författare)
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Wolbachia prevalence in the vector species Culex pipiens and Culex torrentium in a Sindbis virus-endemic region of Sweden
- 2021
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Ingår i: Parasites & Vectors. - : BioMed Central (BMC). - 1756-3305. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Wolbachia pipientis are endosymbiotic bacteria present in a large proportion of terrestrial arthropods. The species is known to sometimes affect the ability of its host to transmit vector-borne pathogens. Central Sweden is endemic for Sindbis virus (SINV), where it is mainly transmitted by the vector species Culex pipiens and Culex torrentium, with the latter established as the main vector. In this study we investigated the Wolbachia prevalence in these two vector species in a region highly endemic for SINV. Methods: Culex mosquitoes were collected using CDC light traps baited with carbon dioxide over 9 years at 50 collection sites across the River Dalalven floodplains in central Sweden. Mosquito genus was determined morphologically, while a molecular method was used for reliable species determination. The presence of Wolbachia was determined through PCR using general primers targeting the wsp gene and sequencing of selected samples. Results: In total, 676 Cx. pipiens and 293 Cx. torrentium were tested for Wolbachia. The prevalence of Wolbachia in Cx. pipiens was 97% (95% CI 94.8-97.6%), while only 0.7% (95% CI 0.19-2.45%) in Cx. torrentium. The two Cx. torrentium mosquitoes that were infected with Wolbachia carried different types of the bacteria. Conclusions: The main vector of SINV in the investigated endemic region, Cx. torrentium, was seldom infected with Wolbachia, while it was highly prevalent in the secondary vector, Cx. pipiens. The presence of Wolbachia could potentially have an impact on the vector competence of these two species. Furthermore, the detection of Wolbachia in Cx. torrentium could indicate horizontal transmission of the endosymbiont between arthropods of different species.
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