TY - JOUR
T1 - Emergence and establishment of Usutu virus infection in wild and captive avian species in and around Zurich, Switzerland-Genomic and pathologic comparison to other central European outbreaks
AU - Steinmetz, Hanspeter W.
AU - Bakonyi, Tamás
AU - Weissenböck, Herbert
AU - Hatt, Jean Michel
AU - Eulenberger, Ulrike
AU - Robert, Nadia
AU - Hoop, Richard
AU - Nowotny, Norbert
N1 - Funding Information:
The authors thank the keepers at Zurich zoo and all the laboratory personnel for their help during the study. The work and organization of Ms. G. Hürlimann is gratefully appreciated. The study was partially supported by the grant OTKA K67900. T. Bakonyi is a grantee of the “Bolyai János” fellowship grant of the Hungarian Academy of Sciences .
PY - 2011/3/24
Y1 - 2011/3/24
N2 - In late summer 2006 considerable mortality in wild and captive Passeriformes and Strigiformes was observed in Zurich, Switzerland. All animals were found in a range of 2km 2. Observed clinical signs involved depression, ruffled plumage, incoordination, seizures and peracute death. Nutritional status was generally moderate to poor in wild birds, and variable in captive animals. Necropsy showed marked splenomegaly, a mild hepatomegaly, and pulmonary hyperemia in most animals. Histopathologic lesions were very discrete and consisted mainly of neuronal necrosis, leucocytolysis in and around the brain blood vessels, and miliary liver necrosis. The diagnosis Usutu virus (USUV) infection was established by USUV-specific immunohistochemistry and reverse transcription-polymerase chain reaction. Partial nucleotide sequence comparisons revealed>99% identity between the viruses that emerged in Zurich in 2006, in Vienna in 2001, and in Budapest in 2005. Since 2008 a significantly lower mortality was observed in wild Passeriformes, but USUV infection was confirmed for the first time beyond Zurich city limits. Indoor housing and regular treatment against ectoparasites are likely to have prevented acute USUV disease in captive Strigiformes. USUV is a mosquito-borne flavivirus causing fatalities in various avian species. After the initial European outbreaks in Austria in 2001 it appears that the virus has extended its range in Central Europe and has established a transmission cycle between local bird and mosquito species. Further episodes of increased avian mortality in the forthcoming years, with impact on wild and captive bird populations, predominantly Passeriformes and Strigiformes, can be anticipated. Furthermore, the possibility of broader dispersal of USUV in Europe during the next mosquito seasons must be considered and an increased mortality in Passeriformes and Strigiformes must be expected until protective " flock immunity" is established. Collections of valuable and endangered Passeriformes and Strigiformes, especially young of the year, should therefore be housed indoors or treated against ectoparasites at acceptable intervals between July and September each year.
AB - In late summer 2006 considerable mortality in wild and captive Passeriformes and Strigiformes was observed in Zurich, Switzerland. All animals were found in a range of 2km 2. Observed clinical signs involved depression, ruffled plumage, incoordination, seizures and peracute death. Nutritional status was generally moderate to poor in wild birds, and variable in captive animals. Necropsy showed marked splenomegaly, a mild hepatomegaly, and pulmonary hyperemia in most animals. Histopathologic lesions were very discrete and consisted mainly of neuronal necrosis, leucocytolysis in and around the brain blood vessels, and miliary liver necrosis. The diagnosis Usutu virus (USUV) infection was established by USUV-specific immunohistochemistry and reverse transcription-polymerase chain reaction. Partial nucleotide sequence comparisons revealed>99% identity between the viruses that emerged in Zurich in 2006, in Vienna in 2001, and in Budapest in 2005. Since 2008 a significantly lower mortality was observed in wild Passeriformes, but USUV infection was confirmed for the first time beyond Zurich city limits. Indoor housing and regular treatment against ectoparasites are likely to have prevented acute USUV disease in captive Strigiformes. USUV is a mosquito-borne flavivirus causing fatalities in various avian species. After the initial European outbreaks in Austria in 2001 it appears that the virus has extended its range in Central Europe and has established a transmission cycle between local bird and mosquito species. Further episodes of increased avian mortality in the forthcoming years, with impact on wild and captive bird populations, predominantly Passeriformes and Strigiformes, can be anticipated. Furthermore, the possibility of broader dispersal of USUV in Europe during the next mosquito seasons must be considered and an increased mortality in Passeriformes and Strigiformes must be expected until protective " flock immunity" is established. Collections of valuable and endangered Passeriformes and Strigiformes, especially young of the year, should therefore be housed indoors or treated against ectoparasites at acceptable intervals between July and September each year.
KW - Blackbirds
KW - Ectoparasites
KW - Herd immunity
KW - House sparrows
KW - Passeriformes
KW - Strigiformes
KW - Switzerland
KW - USUV
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U2 - 10.1016/j.vetmic.2010.09.018
DO - 10.1016/j.vetmic.2010.09.018
M3 - Article
C2 - 20980109
AN - SCOPUS:79951578091
SN - 0378-1135
VL - 148
SP - 207
EP - 212
JO - Veterinary Microbiology
JF - Veterinary Microbiology
IS - 2-4
ER -