Abstract
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.
Highlights
Usutu virus (USUV) is a flavivirus transmitted by ornithophilic mosquitoes
The virus was isolated from a number of mosquito species of the genera: Aedes, Anopheles, Culex, Culiseta, Ochlerotatus summarized in [1]), they are considered as potential vectors
A variety of resident (e.g., Eurasian magpie (Pica pica), domestic pigeon (Columba livia domestica), hooded crow (Corvus cornix), carrion crow (Corvus corone), Eurasian nuthatch (Sita europea), great tit (Parus major)) and partially migratory or migratory (e.g., Euroasian blackbird (Turdus merula), song thrush (T. philomelos), white stork (Ciconia ciconia), common redstart (Phoenicurus phoenicurus), and European robin (Erithacus rubecula)) bird species are considered the probable natural hosts in Europe, based on serologic evidence and direct proof of the virus [1,6,7], the virus was found in other vertebrates, such as bats [8], rodents and a shrew [9]
Summary
Usutu virus (USUV) is a flavivirus (family Flaviviridae, genus Flavivirus) transmitted by ornithophilic mosquitoes. The virus was isolated from a number of mosquito species of the genera: Aedes, Anopheles, Culex, Culiseta, Ochlerotatus summarized in [1]), they are considered as potential vectors. Passeriform and strigiform birds are sensitive to the infection in the sense of symptomatic disease (symptoms include: featherless heads, apathy, inability to fly, incoordination, splenomegaly, necrosis in liver and spleen, and signs of encephalitis) frequently followed by death [10,11,12,13,14]. Infections of humans are mostly associated with asymptomatic course [15,16,17] or mild symptoms including fever, rash or jaundice [18]. Not exclusively, in immunocompromised patients, USUV may cause infections of central nervous system [19,20,21]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
