The European subtype of tick-borne encephalitis virus (TBEV-Eur; species Orthoflavivirus encephalitidis, family Flaviviridae) was the only tick-borne flavivirus present in central Europe known to cause neurologic disease in humans and several animal species. Here, we report a tick-borne flavivirus isolated from Alpine chamois (Rupicapra rupicapra rupicapra) with encephalitis and attached ticks, present over a wide area in the Alps. Cases were detected in 2017 in Salzburg, Austria, and 2023 in Lombardy and Piedmont, Italy. The virus strains exhibit 94.8-97.3% nucleotide identities to each other and are more closely related to Louping ill viruses (LIV; Orthoflavivirus loupingi; 90-92% identities) than to TBEV-Eur (less than 88%). The chamois-derived virus strains, tentatively termed "Alpine chamois encephalitis virus", form a well-supported independent genetic clade with Spanish goat encephalitis virus, clearly separated from other LIV. This supports its designation as a new virus subtype with the proposed shared taxonomic name "Spanish goat and Alpine chamois encephalitis virus subtype" within the species Orthoflavivirus loupingi. The zoonotic potential of this newly identified virus subtype as well as its host range in other animal species including farm animals needs to be further investigated.

• Klíčová slova
• Alpine chamois, Flaviviridae, Ixodes ricinus, Rupicapra rupicapra, Spanish goat encephalitis virus, encephalitis, flavivirus, louping ill virus, neurotropic, tick-borne encephalitis virus,
• MeSH
• fylogeneze MeSH
• genom virový MeSH
• klíšťata virologie   MeSH
• klíšťová encefalitida * veterinární   virologie   epidemiologie   MeSH
• Rupicapra * virologie   MeSH
• viry klíšťové encefalitidy * genetika   izolace a purifikace   klasifikace   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Itálie epidemiologie   MeSH
• Rakousko epidemiologie   MeSH

The emergence of West Nile virus (WNV) and Usutu virus (USUV) in addition to the autochthonous tick-borne encephalitis virus (TBEV) in Europe causes rising concern for public and animal health. The first equine case of West Nile neuroinvasive disease in Austria was diagnosed in 2016. As a consequence, a cross-sectional seroprevalence study was conducted in 2017, including 348 equids from eastern Austria. Serum samples reactive by ELISA for either flavivirus immunoglobulin G or M were further analyzed with the plaque reduction neutralization test (PRNT-80) to identify the specific etiologic agent. Neutralizing antibody prevalences excluding vaccinated equids were found to be 5.3% for WNV, 15.5% for TBEV, 0% for USUV, and 1.2% for WNV from autochthonous origin. Additionally, reverse transcription quantitative polymerase chain reaction (RT-qPCR) was performed to detect WNV nucleic acid in horse sera and was found to be negative in all cases. Risk factor analysis did not identify any factors significantly associated with seropositivity.

• Klíčová slova
• Austria, Usutu virus, West Nile virus, epidemiology, flavivirus, horses, seroprevalence, tick-borne encephalitis virus,
• MeSH
• endemické nemoci veterinární   MeSH
• Equidae virologie   MeSH
• Flavivirus imunologie   MeSH
• infekce viry z rodu Flavivirus epidemiologie   veterinární   MeSH
• klíšťová encefalitida epidemiologie   veterinární   MeSH
• koně MeSH
• nemoci koní epidemiologie   MeSH
• protilátky virové krev   MeSH
• průřezové studie MeSH
• rizikové faktory MeSH
• séroepidemiologické studie MeSH
• virus západního Nilu imunologie   MeSH
• viry klíšťové encefalitidy imunologie   MeSH
• západonilská horečka epidemiologie   veterinární   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rakousko epidemiologie   MeSH
• Názvy látek
• protilátky virové MeSH

Usutu virus (USUV) is a flavivirus (Flaviviridae: Flavivirus) of an African origin transmitted among its natural hosts (diverse species of birds) by mosquitoes. The virus was introduced multiple times to Europe where it caused mortality of blackbirds (Turdus merula) and certain other susceptible species of birds. In this study, we report detection of USUV RNA in blackbirds, Culex pipiens and Cx. modestus mosquitoes in the Czech Republic, and isolation of 10 new Czech USUV strains from carcasses of blackbirds in cell culture. Multiple lineages (Europe 1, 2 and Africa 3) of USUV were found in blackbirds and mosquitoes in the southeastern part of the country. A single USUV lineage (Europe 3) was found in Prague and was likely associated with increased mortalities in the local blackbird population seen in this area in 2018. USUV genomic RNA (lineage Europe 2) was detected in a pool of Cx. pipiens mosquitoes from South Bohemia (southern part of the country), where no major mortality of birds has been reported so far, and no flavivirus RNA has been found in randomly sampled cadavers of blackbirds. The obtained data contributes to our knowledge about USUV genetic variability, distribution and spread in Central Europe.

• Klíčová slova
• Culex spp., Usutu virus, blackbird, mosquito,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: West Nile virus (WNV) is currently the most important mosquito-borne pathogen spreading in Europe. Data on overwintering of WNV in mosquitoes are crucial for understanding WNV circulation in Europe; nonetheless, such data were not available so far. RESULTS: A total of 28,287 hibernating mosquitoes [27,872 Culex pipiens, 73 Anopheles maculipennis (sensu lato), and 342 Culiseta annulata], caught in February or March between 2011 and 2017 in a WNV-endemic region of South Moravia, Czech Republic, were screened for the presence of WNV RNA. No WNV positive pools were found from 2011 to 2016, while lineage 2 WNV RNA was detected in three pools of Culex pipens mosquitoes collected in 2017 at two study sites. CONCLUSIONS: To the best of our knowledge, this is the first record of WNV RNA in overwintering mosquitoes in Europe. The data support the hypothesis of WNV persistence in mosquitoes throughout the winter season in Europe.

• Klíčová slova
• Anopheles maculipennis, Culex pipiens, Culiseta annulata, Czech Republic, Flavivirus, Hibernation, Overwintering, West Nile fever, West Nile virus,
• MeSH
• Culicidae virologie   MeSH
• hmyz - vektory virologie   MeSH
• lidé MeSH
• roční období MeSH
• virus západního Nilu genetika   izolace a purifikace   fyziologie   MeSH
• západonilská horečka epidemiologie   přenos   virologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH

The detection of West Nile virus (WNV) nucleic acid in a blood donation from Vienna, Austria, as well as in Culex pipiens pupae and egg rafts, sampled close to the donor's residence, is reported. Complete genomic sequences of the human- and mosquito-derived viruses were established, genetically compared and phylogenetically analyzed. The viruses were not identical, but closely related to each other and to recent Czech and Italian isolates, indicating co-circulation of related WNV strains within a confined geographic area. The detection of WNV in a blood donation originating from an area with low WNV prevalence in humans (only three serologically diagnosed cases between 2008 and 2014) is surprising and emphasizes the importance of WNV nucleic acid testing of blood donations even in such areas, along with active mosquito surveillance programs.

• MeSH
• Culex virologie   MeSH
• dárci krve * MeSH
• dospělí MeSH
• epidemiologické monitorování MeSH
• fylogeneze MeSH
• hmyz - vektory virologie   MeSH
• lidé MeSH
• molekulární typizace MeSH
• myši inbrední ICR MeSH
• myši MeSH
• polymerázová řetězová reakce MeSH
• polyproteiny genetika   MeSH
• virové proteiny genetika   MeSH
• virus západního Nilu klasifikace   genetika   izolace a purifikace   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• západonilská horečka diagnóza   přenos   virologie   MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rakousko MeSH
• Názvy látek
• polyproteiny MeSH
• virové proteiny MeSH