| 1. |
- Ahola, T, et al.
(författare)
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Therapeutics and vaccines against chikungunya virus
- 2015
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Ingår i: Vector borne and zoonotic diseases (Larchmont, N.Y.). - : Mary Ann Liebert Inc. - 1557-7759 .- 1530-3667. ; 15:4, s. 250-257
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Andersson, Martin, et al.
(författare)
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Co-Infection with 'Candidatus Neoehrlichia mikurensis' and Borrelia afzelii in Ixodes ricinus Ticks in Southern Sweden.
- 2013
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1557-7759 .- 1530-3667. ; 13:7, s. 438-442
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Tidskriftsartikel (refereegranskat)abstract
- Abstract The tick-borne bacterium 'Candidatus Neoehrlichia mikurensis' has recently been recognized as a human pathogen in Europe and appears to be the second most common pathogenic bacterium in Ixodes ricinus ticks in central Europe, second to Borrelia afzelii. Here, we investigate the prevalence of 'Candidatus N. mikurensis' in host-seeking ticks in southern Sweden and the rate of co-infection with B. afzelii. We developed a real-time qPCR assay targeting the groEL gene of 'Candidatus N. mikurensis' and applied this assay to 949 I. ricinus ticks collected at several locations over 2 years. We found an overall prevalence of 6.0%, which means that Candidatus N. mikurensis is one of the most common tick-transmitted zoonotic agents in this area. Co-infections with both 'Candidatus N. mikurensis' and B. afzelii occurred in 2.1% of the ticks, which is significantly more than expected under random co-occurrence. The infection intensity (number of bacterial cells) of 'Candidatus N. mikurensis' was not affected by co-infection with B. afzelii, and vice versa. We conclude that there is a risk for simultaneous transmission of these 2 tick-borne pathogens. The potential medical consequences of this require further investigation.
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| 3. |
- Bennet, Louise, et al.
(författare)
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Effect of Gender on Clinical and Epidemiologic Features of Lyme Borreliosis
- 2007
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Ingår i: Vector Borne and Zoonotic Diseases. - : Vector-borne and zoonotic diseases. - 1530-3667 .- 1557-7759. ; 7:1, s. 34-41
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Tidskriftsartikel (refereegranskat)abstract
- The aim is to highlight the influence of patients’ gender on Lyme borreliosis and especially erythema migrans (EM), focusing on exposure to tick bites, epidemiology, and the clinical picture. All studies were conducted in the county of Blekinge, located in southeastern Sweden. A prospective study was conducted in 235 individuals (women, n=110; men, n=125) engaged in recreational or occupational activities focusing on exposure to tick bites. A retrospective epidemiological study evaluating 123,495 electronic patients´ records (women, n=61,712; men, n=61,783) and a prospective clinical study including 118 patients (women, n=54; men, n=64) 18 years or older seeking care for EM > 5 cm in diameter with genospecies verified by polymerase chain reaction were conducted. Results: Women 40 years or older had a 48% higher risk than men 40 years or older and 42% higher risk than women younger than 40 years of attracting tick bites (0.0188 versus 0.0127 and 0.0188 versus 0.0132 tick bites respectively per hour). Additionally they had a 96% higher risk than men younger than 40 years of attracting tick bites (0.0188 versus 0.0096). The annual incidence rate of EM in women was 506 and in men 423 cases per 100,000 inhabitants (p<0.001). Significant differences in incidence rates occurred in those 40 years or older. Odds ratios for males infected with Borrelia afzelii developing nonannular EM were 0.09 (95% confidence interval [CI] 0.03 to 0.33) in comparison with females infected by Borrelia afzelii. Conclusions: Significant gender differences in the risk of contracting tick bites, incidence rates, and clinical picture of EM have been observed. Exposure to tick bites alone may not explain these observations and further studies need to be done to clarify the biologic, immunologic, and sociological mechanisms causing these differences.
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| 4. |
- Bergqvist, Joakim, et al.
(författare)
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Detection and Isolation of Sindbis Virus from Mosquitoes Captured During an Outbreak in Sweden, 2013
- 2015
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 15:2, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- Mosquito-borne alphaviruses have the potential to cause large outbreaks throughout the world. Here we investigated the causative agent of an unexpected Sindbis virus (SINV) outbreak during August-September, 2013, in a previously nonendemic region of Sweden. Mosquitoes were collected using carbon dioxide-baited CDC traps at locations close to human cases. The mosquitoes were initially screened as large pools by SINV-specific quantitative RT-PCR, and the SINV-positive mosquitoes were species determined by single-nucleotide polymorphism (SNP) analysis, followed by sequencing the barcoding region of the cytochrome oxidase I gene. The proportion of the collected mosquitoes was determined by a metabarcoding strategy. By using novel strategies for PCR screening and genetic typing, a new SINV strain, Lovanger, was isolated from a pool of 1600 mosquitoes composed of Culex, Culiseta, and Aedes mosquitoes as determined by metabarcoding. The SINV-positive mosquito Culiseta morsitans was identified by SNP analysis and sequencing. After whole-genome sequencing and phylogenetic analysis, the SINV Lovanger isolate was shown to be most closely similar to recent Finnish SINV isolates. In conclusion, within a few weeks, we were able to detect and isolate a novel SINV strain and identify the mosquito vector during a sudden SINV outbreak.
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| 5. |
- Brissette, Catherine, et al.
(författare)
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An Expert Panel DiscussionLyme Disease in Europe
- 2023
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Ingår i: Vector Borne and Zoonotic Diseases. - : MARY ANN LIEBERT, INC. - 1530-3667 .- 1557-7759. ; 23:S1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Ecke, Frauke, et al.
(författare)
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Geographical Distribution of Ljungan Virus in Small Mammals in Europe
- 2020
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Ingår i: Vector-Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 20, s. 692-702
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Tidskriftsartikel (refereegranskat)abstract
- Ljungan virus (LV), which belongs to the Parechovirus genus in the Picornaviridae family, was first isolated from bank voles (Myodes glareolus) in Sweden in 1998 and proposed as a zoonotic agent. To improve knowledge of the host association and geographical distribution of LV, tissues from 1685 animals belonging to multiple rodent and insectivore species from 12 European countries were screened for LV-RNA using reverse transcriptase (RT)-PCR. In addition, we investigated how the prevalence of LV-RNA in bank voles is associated with various intrinsic and extrinsic factors. We show that LV is widespread geographically, having been detected in at least one host species in nine European countries. Twelve out of 21 species screened were LV-RNA PCR positive, including, for the first time, the red vole (Myodes rutilus) and the root or tundra vole (Alexandromys formerly Microtus oeconomus), as well as in insectivores, including the bicolored white-toothed shrew (Crocidura leucodon) and the Valais shrew (Sorex antinorii). Results indicated that bank voles are the main rodent host for this virus (overall RT-PCR prevalence: 15.2%). Linear modeling of intrinsic and extrinsic factors that could impact LV prevalence showed a concave-down relationship between body mass and LV occurrence, so that subadults had the highest LV positivity, but LV in older animals was less prevalent. Also, LV prevalence was higher in autumn and lower in spring, and the amount of precipitation recorded during the 6 months preceding the trapping date was negatively correlated with the presence of the virus. Phylogenetic analysis on the 185 base pair species-specific sequence of the 5 ' untranslated region identified high genetic diversity (46.5%) between 80 haplotypes, although no geographical or host-specific patterns of diversity were detected.
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| 7. |
- Ecke, Frauke, et al.
(författare)
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Puumala Orthohantavirus Infection Does Not Affect the Trapping Success of Its Reservoir Host
- 2022
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert. - 1530-3667 .- 1557-7759. ; 22:5, s. 297-299
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Tidskriftsartikel (refereegranskat)abstract
- Pathogens might affect behavior of infected reservoir hosts and hence their trappability, which could bias population estimates of pathogen prevalence. In this study, we used snap-trapping data on Puumala orthohantavirus (PUUV)-infected (n = 1619) and noninfected (n = 6940) bank voles (Myodes glareolus) from five vole cycles, normally representing increase, peak, and decline phase, to evaluate if infection status affected trapping success. If PUUV infection, as previously suggested, increases activity and/or mobility, we would expect a higher proportion of infected than noninfected specimens in the first trapping night. However, the proportion of PUUV-infected voles did not differ across the three trapping nights. We conclude that PUUV infection did not affect trapping success, confirming snap trapping as an appropriate trapping method for studies on PUUV prevalence and likely other orthohantaviruses.
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| 8. |
- Ecke, Frauke, et al.
(författare)
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Selective Predation by Owls on Infected Bank Voles (Myodes glareolus) as a Possible Sentinel of Tularemia Outbreaks
- 2020
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert. - 1530-3667 .- 1557-7759. ; 20:8, s. 630-632
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Tidskriftsartikel (refereegranskat)abstract
- Tularemia is a widely spread zoonotic disease in the northern hemisphere, caused by the bacterium Francisella tularensis. In humans, tularemia is an acute febrile illness with incidence peaks in late summer to early autumn of outbreak years, but there is no early warning system in place that can reduce the impact of disease by providing timely risk information. In this study, we revisit previously unpublished data on F. tularensis in water, sediment, soil, and small mammals from 1984 in northern Sweden. In addition, we used human case data from the national surveillance system for tularemia in the same year. In the environmental and small mammal material, bank vole (Myodes glareolus) samples from urine and bladder were the only samples that tested positive for F. tularensis. The prevalence of F. tularensis among trapped bank voles was 13.5%, although all six bank voles that were retrieved from owl nest boxes in early May tested positive. Forty-two human tularemia cases were reported from August to December in 1984. Based on these results, we encourage investigating the potential role of tularemia-infected bank voles retrieved from owl nest boxes in spring as an early warning for outbreaks of tularemia among humans in summer and autumn of the same year.
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| 9. |
- Elfving, Karin, et al.
(författare)
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Serologic and Molecular Prevalence of Rickettsia helvetica and Anaplasma phagocytophilum in Wild Cervids and Domestic Mammals in the Central Parts of Sweden
- 2015
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 15:9, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- Both Rickettsia helvetica and Anaplasma phagocytophilum are common in Ixodes ricinus ticks in Sweden. Knowledge is limited regarding different animal species' competence to act as reservoirs for these organism. For this reason, blood samples were collected from wild cervids (roe deer, moose) and domestic mammals (horse, cat, dog) in central Sweden, and sera were tested using immunofluorescence assay to detect antibodies against spotted fever rickettsiae using Rickettsia helvetica as antigen. Sera with a titer >= 1:64 were considered as positive, and 23.1% (104/450) of the animals scored positive. The prevalence of seropositivity was 21.5% (23/107) in roe deer, 23.3% (21/90) in moose, 36.5% (23/63) in horses, 22.1% (19/90) in cats, and 17.0% (17/100) in dogs. PCR analysis of 113 spleen samples from moose and sheep from the corresponding areas were all negative for rickettsial DNA. In roe deer, 85% (91/107) also tested seropositive for A. phagocytophilum with a titer cutoff of 1:128. The findings indicate that the surveyed animal species are commonly exposed to rickettsiae and roe deer also to A. phagocytophilum.
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| 10. |
- Elväng, Annelie, et al.
(författare)
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Sequencing of a Tick-Borne Encephalitis Virus from Ixodes ricinus Reveals a Thermosensitive RNA Switch Significant for Virus Propagation in Ectothermic Arthropods
- 2011
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 11:6, s. 649-658
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis virus (TBEV) is a flavivirus with major impact on global health. The geographical TBEV distribution is expanding, thus making it pivotal to further characterize the natural virus populations. In this study, we completed the earlier partial sequencing of a TBEV pulled out of a pool of RNA extracted from 115 ticks collected on Torö in the Stockholm archipelago. The total RNA was sufficient for all sequencing of a TBEV genome (Torö-2003), without conventional enrichment procedures such as cell culturing or suckling mice amplification. To our knowledge, this is the first time that the genome of TBEV has been sequenced directly from an arthropod reservoir. The Torö-2003 sequence has been characterized and compared with other TBE viruses. In silico analyses of secondary RNA structures formed by the two untranslated regions revealed a temperature-sensitive structural shift between a closed replicative form and an open AUG accessible form, analogous to a recently described bacterial thermoswitch. Additionally, novel phylogenetic conserved structures were identified in the variable part of the 3′-untranslated region, and their sequence and structure similarity when compared with earlier identified structures suggests an enhancing function on virus replication and translation. We propose that the thermo-switch mechanism may explain the low TBEV prevalence often observed in environmentally sampled ticks. Finally, we were able to detect variations that help in the understanding of virus adaptations to varied environmental temperatures and mammalian hosts through a comparative approach that compares RNA folding dynamics between strains with different mammalian cell passage histories.
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| 11. |
- Goeijenbier, Marco, et al.
(författare)
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Emerging Viruses in the Republic of Suriname : Retrospective and Prospective Study into Chikungunya Circulation and Suspicion of Human Hantavirus Infections, 2008-2012 and 2014
- 2015
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 15:10, s. 611-618
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Suriname is a country on the northeastern Atlantic coast of South America. It is unique in the sense that different ethnic cultures live together within the country, resulting in high levels of transport of both humans and products between the Asian, African, and European continents as well as the Caribbean. Travel is only one of the many factors present in Suriname contributing to the risk for the emergence or introduction of any infectious disease. Recently, circulation of both chikungunya virus (CHIKV) and hantavirus was reported in areas neighboring Suriname. Here we report a retrospective and prospective study into chikungunya and hantavirus circulation. Methods: A chikungunya and hantavirus retrospective serological study was conducted on samples submitted for dengue, leptospirosis, and/or influenza virus diagnostics between 2008 and 2012 to the Bureau of Public Health in Suriname. This was followed by a prospective CHIKV serological and molecular surveillance study until the detection of the first autochthonous CHIKV cases in Suriname in May and June of 2014. Results: None of the tested samples showed the presence of CHIKV antibodies in the retrospective serological study. Prospective testing of CHIKV-suspected patients resulted in the detection of the first autochthonous CHIKV cases in Suriname in May, 2015. In one sample, we were able to isolate and sequence the virus. Retrospective testing for the presence of hantavirus antibodies showed a relative high response in both pan-hantavirus enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA). However, neutralization tests did not yield any evidence for infection with either Seoul or Andes hantavirus. Conclusion: Here we report the presence of CHIKV in the republic of Suriname and the first serological indication of hantavirus infections in symptomatic patients.
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| 12. |
- Gunnarsson, Gunnar, et al.
(författare)
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Zero Prevalence of Influenza A Virus in Two Raptor Species by Standard Screening
- 2010
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Ingår i: Vector-borne and zoonotic diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 10:4, s. 387-390
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Tidskriftsartikel (refereegranskat)abstract
- Disease can have sever impact on animal populations, especially in rare species. Baseline data for atypical host species are missing for a range of infectious diseases, although such hosts are potentially more affected than the normal vectors and reservoir species. If highly pathogenic avian influenza strikes rare birds of prey, this may have crucial impact on the predator species itself, but also on the food web in which it interacts. Here we present the first large-scale screening of raptors that regularly consume birds belonging to the natural reservoir of influenza A viruses. Influenza A virus prevalence was studied in two rare raptors, the white-tailed sea eagle (Haliaetus albicilla) and the peregrine falcon (Falco peregrinus). Nestlings were screened for active (181 white-tailed sea eagles and 168 peregrine falcons) and past (123 white-tailed sea eagles and 6 peregrine falcons) infection in 2006-2007, and an additional 20 succumbed adult white-tailed sea eagles were sampled in 2003-2006. Neither high- nor low-pathogenic influnza infections were found in our sample, but this does not rule out that the former may have major impact on rare raptors and their food webs.
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| 13. |
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| 14. |
- Haemig, Paul D., et al.
(författare)
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Barn Swallows (Hirundo rustica) Test Negative for Salmonella
- 2008
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert. - 1530-3667 .- 1557-7759. ; 8:4, s. 451-453
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Tidskriftsartikel (refereegranskat)abstract
- Farmers around the world have been urged to eliminate barn swallows (Hirundo rustica) from their buildings, based on the unproven assumption that these birds amplify and spread Salmonella to livestock, humans, and stored food. However, we tested over 500 barn swallows in Sweden and found no evidence that they carry Salmonella. Our results cast doubt on the hypothesis that barn swallows are competent reservoirs of Salmonella and suggest that their role, if any, is limited to being accidental hosts of the bacterium.
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| 15. |
- Hesson, Jenny C., et al.
(författare)
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Geographic distribution and relative abundance of the sibling vector species Culex torrentium and Culex pipiens in Sweden
- 2011
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 11:10, s. 1383-1389
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Tidskriftsartikel (refereegranskat)abstract
- Culex torrentium and Culex pipiens are sibling species and potential viral vectors that coexist in Europe. Larvae and females of the two species are morphologically almost identical, and reliable identification can only be done on males. To investigate the distribution and relative abundance of the two species in Sweden, we collected Culex larvae from sites spread over the country, identified them as Culex pipiens/torrentium based on morphology, and identified them to species using a recently developed restriction enzyme method. Cx. torrentium was the dominant species (89%, n = 1012) and it occurred in 48 of the 49 sites investigated, and also dominated in most of the study sites. The proportion of Cx. pipiens larvae in relation to Cx. torrentium collected at each site decreased with both increasing latitude and altitude, and the presence of Cx. pipiens decreased with latitude. In addition, Cx. pipiens/torrentium females were sampled with Centres for Disease Control light traps baited with carbon dioxide. The overall country mean was 4.0 Cx. pipiens/torrentium caught per trap night, with decreasing numbers of Cx. pipiens/torrentium caught per trap night with increasing latitude. Thus, the abundance of Cx. pipiens/torrentium decreased, but the proportion Cx. torrentium increased, with increasing latitude. This is the first study that shows the vast dominance of Cx. torrentium over Cx. pipiens in Sweden. The unexpected dominance of Cx. torrentium highlights the importance of distinguishing between the two species in studies of Culex-borne arboviruses in Europe.
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| 16. |
- Jaaskelainen, Anne J., et al.
(författare)
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Development and Evaluation of a Real-Time RT-qPCR for Detection of Crimean-Congo Hemorrhagic Fever Virus Representing Different Genotypes
- 2014
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert. - 1530-3667 .- 1557-7759. ; 14:12, s. 870-872
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Tidskriftsartikel (refereegranskat)abstract
- Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic disease caused by a nairovirus belonging to family Bunyaviridae. The CCHF virus (CCHFV) can be transmitted to humans by Hyalomma ticks as well as by direct contact with infected body fluids or tissues from viremic livestock or humans. Our aim was to set up a fast RT-qPCR for detection of the different CCHFV genotypes in clinical samples, including an inactivation step to make the sample handling possible in lower biosafety levels (BSL) than BSL-4. This method was evaluated against commercial reference assays and international External Quality Assessment (EQA) samples. The analytical limit of detection for the developed CCHFV-S RT-qPCR was 11 CCHFV genomes per reaction. After exclusion of four dubious samples, we studied 38 CCHFV-positive samples (using reference tests) of which 38 were found positive by CCHFV-S RT-qPCR, suggesting a sensitivity of 100%. CCHFV-S RT q-PCR detected all eight different CCHFV strains representing five different CCHFV genotypes. In conclusion, the CCHFV-S RT-qPCR described in this study was evaluated using various sources of CCHFV samples and shown to be an accurate tool to detect human CCHFV infection caused by different genotypes of the virus.
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| 17. |
- Johansson Wensman, Jonas, et al.
(författare)
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Application of Viral Metagenomics for Study of Emerging and Reemerging Tick-Borne Viruses
- 2020
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Ingår i: Vector-Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 20, s. 557-565
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Tidskriftsartikel (refereegranskat)abstract
- Ticks are important vectors for different tick-borne viruses, some of which cause diseases and death in humans, livestock, and wild animals. Tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Kyasanur forest disease virus, severe fever with thrombocytopenia syndrome virus, Heartland virus, African swine fever virus, Nairobi sheep disease virus, and Louping ill virus are just a few examples of important tick-borne viruses. The majority of tick-borne viruses have RNA genomes that routinely undergo rapid genetic modifications such as point mutations during their replication. These genomic changes can influence the spread of viruses to new habitats and hosts and lead to the emergence of novel viruses that can pose a threat to public health. Therefore, investigation of the viruses circulating in ticks is important to understand their diversity, host and vector range, and evolutionary history, as well as to predict new emerging pathogens. The choice of detection method is important, as most methods detect only those viruses that have been previously well described. On the other hand, viral metagenomics is a useful tool to simultaneously identify all the viruses present in a sample, including novel variants of already known viruses or completely new viruses. This review describes tick-borne viruses, their historical background of emergence, and their reemergence in nature, and the use of viral metagenomics for viral discovery and studies of viral evolution.
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| 18. |
- Johansson Wensman, Jonas, et al.
(författare)
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Genetic Relationship Between Hard Ticks (Ixodidae) Infesting Cattle from Select Areas of a Wildlife-Livestock Interface Ecosystem at Mikumi National Park, Tanzania
- 2021
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Ingår i: Vector-Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 21, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- Background: There has recently been a substantial increase in the number of tick species and tick-borne infectious agents in Tanzania. Owing to their impact on human, livestock, and wild animal health, increased knowledge of ticks is needed. So far, no published data on the genetic relationship between hard tick (Ixodidae) sequences collected from cattle are available in Tanzania.Methods: Ticks from cattle in the wards, which lie at the border of Mikumi National Park, were collected in the dry season, November to December 2019. Morphological identification of ticks was initially performed at the genus level. To identify ticks at the species level, molecular analysis based on the 16S rRNA gene was performed. Evolutionary relationships and genetic distances between ticks were determined using MaximumLikelihood and Kimura 2-parameter methods, respectively.Results: Based on morphology, two genera (Rhipicephalus and Hyalomma) were identified in the 630 adult ticks collected from a total of 252 cattle. Six species (Rhipicephalus microplus, Rhipicephalus evertsi, Hyalomma marginatum, Hyalomma rufipes, Hyalomma truncatum, and Hyalomma turanicum) were confirmed by BLASTn and phylogenetic analyses. Considerable mean and pairwise genetic distances were observed for Rhipicephalus and Hyalomma genera.Conclusion: The presence of different phylogenetic clusters and considerable mean and pairwise genetic distances observed reflect possible biological diversity of hard ticks present in the study area. Considering the value of the cattle in the livelihoods and economies of people and the country, the outcomes of this study will be useful in planning integrated control strategies for ticks and tick-borne diseases in Tanzania.
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| 19. |
- Jourdain, Elsa, et al.
(författare)
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Surveillance for West Nile virus in wild birds from northern Europe.
- 2011
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 11:1, s. 77-79
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Tidskriftsartikel (refereegranskat)abstract
- A total of 1935 migratory birds from 104 different species were captured in southeastern Sweden in 2005-2006 and tested for antibodies against West Nile virus (WNV). Overall, 46 birds (2.4%; binomial confidence limits, 1.8-3.2) were positive by blocking-ELISA, but only 2 (0.10%; binomial confidence limits, 0.0-0.4) had antibodies detectable by both blocking-ELISA and WNV neutralization test. ELISA-positive birds included long- and short-distance migrants likely exposed to WNV while wintering in or migrating through areas enzootic for WNV. Exposure to a cross-reactive Flavivirus was suspected for short-distance migrants of the Turdidae family, but no cross-neutralization with tick-borne encephalitis and Usutu viruses was observed.
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| 20. |
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| 21. |
- Khalil, Hussein, et al.
(författare)
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Dynamics and Drivers of Hantavirus Prevalence in Rodent Populations
- 2014
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert, Inc. publishers. - 1530-3667 .- 1557-7759. ; 14:8, s. 537-551
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Forskningsöversikt (refereegranskat)abstract
- Human encroachment on wildlife habitats has contributed to the emergence of several zoonoses. Pathogenic hantaviruses are hosted by rodents and cause severe diseases in the Americas and Eurasia. We reviewed several factors that potentially drive prevalence (the proportion of infected rodents) in host populations. These include demography, behavior, host density, small mammal diversity, predation, and habitat and landscape characteristics. This review is the first to include a quantitative summary of the literature investigating hantavirus prevalence in rodents. Demographic structure and density were investigated the most and predation the least. Reported effects of demographic structure and small mammal diversity were consistent, whereby reproductive males were most likely to be infected and prevalence decreased with small mammal diversity. The influences of habitat and landscape properties are often complex and indirect. The relationship between density and prevalence merits more investigation. Most hantavirus hosts are habitat generalists and their control is challenging. Incorporating all potential factors and their interactions is essential to understanding and controlling infection in host populations.
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| 22. |
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| 23. |
- Larsson, Christer, 1975-, et al.
(författare)
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First Record of Lyme Disease Borrelia in the Arctic
- 2007
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 7:3, s. 453-456
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Tidskriftsartikel (refereegranskat)abstract
- The epidemiology and ecology of Lyme disease is very complex, and its reported geographical distribution is constantly increasing. Furthermore, the involvement of birds in long distance dispersal and their role as reservoir hosts is now well established. In this study, we have shown that sea birds in the Arctic region of Norway carry Ixodes uriae ticks infected with Lyme disease Borrelia garinii spirochetes. Interestingly, DNA sequencing showed that these isolates are closely related to B. garinii previously isolated from birds, as well as from clinical specimens in northern Europe.
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| 24. |
- Lindahl, Johanna
(författare)
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Relative Distribution, Diversity, and Bloodmeal Sources of Mosquitoes and Known Vectors of Rift Valley Fever Phlebovirus in Three Differing Ecosystems in Bura, Tana River County, Kenya
- 2020
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Ingår i: Vector-Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 20, s. 365-373
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Tidskriftsartikel (refereegranskat)abstract
- Environmental modifications disturb the equilibrium of mosquito populations, altering the risk of mosquito-borne diseases. Mosquito distribution, diversity, and bloodmeal sources were examined to compare Rift Valley fever (RVF) risk among irrigated, riverine, and pastoral ecosystems in Bura, Tana River County, Kenya, between September 2014 and June 2015. Thirty-eight households and 21 irrigation fields were selected for the study. Mosquitoes were trapped with carbon dioxide-impregnated CDC traps, one trap per household and three traps per irrigated field, and morphologically identified using taxonomic keys. Host DNA was extracted from engorged females and cytochrome b genes amplified by PCR to identify sources of bloodmeals. A total of 21,015 mosquitoes were collected; 5742 within households in the 3 ecosystems and 15,273 within irrigated fields. Mosquitoes collected within irrigated fields belonged to 8 genera and 37 species, while those from households within the irrigation scheme belonged to 6 genera and 29 species. Collections from riverine and pastoral households belonged to five and four genera, respectively. The most abundant genera in the irrigated fields were Aedes (21%) and Mansonia (22%), while Anopheles (43%) was the most abundant within households. Most mosquitoes in riverine and pastoral households belonged to Anopheles (76%) and Aedes (65%) genera, respectively. Seasonal variation driven by rainfall was evidenced by spikes in mosquito numbers within irrigated and riverine ecosystems. Host species identification revealed that goats and humans were the main sources of bloodmeal. There was an overall increase in mosquito abundance and diversity as a result of the presence of the irrigated ecosystem in this county, and an increased availability of highly RVF-susceptible hosts as a result of the establishment and concentration of residential areas, promoting potential vector-host contacts. These results highlight the impact of anthropogenic changes on mosquito ecology, potentially heightening the risk of transmission and maintenance of RVF in this region.
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- Litzba, Nadine, et al.
(författare)
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Evaluation of Different Serological Diagnostic Methods for Tick-Borne Encephalitis Virus : Enzyme-Linked Immunosorbent, Immunofluorescence, and Neutralization Assay
- 2014
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Ingår i: Vector Borne and Zoonotic Diseases. - : Mary Ann Liebert Inc. - 1530-3667 .- 1557-7759. ; 14:2, s. 149-159
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Tidskriftsartikel (refereegranskat)abstract
- Tick-borne encephalitis (TBE) is a zoonotic disease, transmitted mainly by the bite of ticks. The TBE virus (TBEV) belongs to the family Flaviviridae, genus Flavivirus and is able to cause meningoencephalitis. For serological TBEV detection, the neutralization test (NT) is the most specific assay available. Different NT protocols are used in the laboratories, and until now the performance of these NTs has never been tested in an external quality assessment (EQA). In this EQA, we compared the results of eight European laboratories in detecting 17 samples (11 TBEV positive, five flavivirus cross reactive, and one negative sample) by NT. Furthermore, 14 of these EQA samples and 15 additional samples were tested in different commercial assays: 15 immunoglobulin G (IgG) enzyme-linked immunosorbent assays (ELISAs) and an immunofluorescence assay (IFA). Four laboratories showed a good NT EQA performance, whereas four laboratories had some sensitivity problems. Additionally, two of these laboratories showed a lack in specificity, misidentifying a dengue-positive sample as TBEV positive. The comparison of the commercial ELISAs revealed a high sensitivity in all assays, but as expected for IgG, the ELISAs showed a high degree of flavivirus cross reactivity. The assessment of Vienna Units in some of the ELISAs revealed deviations in the standards used by the different companies. Therefore, these standards should be revised. Generally, in this EQA, we found that reliable NT protocols are used in most of the laboratories, and the evaluation of the IgG ELISAs and the IFA showed a good agreement.
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