title: Tembusu virus infection in Cherry Valley ducks: the effect of age at infection.
abstract: Three groups of Cherry Valley ducks at 5 day, 2 week and 5 week of age were intranasally infected with the WFCL strain of Tembusu virus (TMUV) to investigate the effect of host age on the outcome of TMUV infection. For each age group, clinical signs, gross and microscopic lesions, viral copy numbers in tissues and serum neutralizing antibody titers were recorded. Age-related differences in the resistance to TMUV infection were observed with younger ducks being more susceptible. Some ducks infected at 5 day and 2 week of age developed severe clinical signs, including severe neurological dysfunction and death. However, subclinical signs and no mortality were observed in ducks infected at 5 week of age. A decline in the severity of gross and microscopic lesions was observed as ducks mature. Systemic infections were established in the three age groups post challenge. Higher viral copy numbers in the tissues, especially in vital organs such as the brain and the heart, were developed in the ducks infected at 5 day of age than older ducks, correlating with the severity of clinical signs and lesions in the tissues. Furthermore, ducks infected at 5 week of age developed significantly higher serum neutralizing antibody titers than ducks infected at 5 day of age as determined by serum neutralization test. Therefore, age-related differences in the resistance to TMUV infection should be considered when studying the pathogenicity, pathogenesis, formulation of the vaccination and therapy strategies of TMUV infection in ducks.
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Sun
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China. Electronic address: yxdiao@126.com.
authors.forename: Y X
authors.initials: YX
authors.lastname: Diao
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: A L
authors.initials: AL
authors.lastname: Lu
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: P P
authors.initials: PP
authors.lastname: Ge
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: D M
authors.initials: DM
authors.lastname: Hao
mesh_terms: D000367:Age Factors; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D001715:Bird Diseases / Q000276:immunology / Q000473:pathology* / Q000821:virology; D004372:Ducks / Q000821:virology*; D005416:Flavivirus; D018177:Flavivirus Infections / Q000276:immunology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D009500:Neutralization Tests; D019562:Viral Load
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral
keywords: Age; Cherry Valley ducks; Experimental infection; Tembusu virus