title: Evidence of possible vertical transmission of Tembusu virus in ducks.
abstract: In 2013, Tembusu virus (TMUV) infection was successively observed on several breeding duck farms in Shandong province, China. Affected ducks showed consistently acute anorexia, diarrhea and egg production drop. 125 hatching eggs produced by TMUV infected breeding ducks from four duck farms were collected. Among them, 35 hatching eggs were selected randomly from all before incubation for vitelline membrane samples collection. The rest of 90 hatching eggs were incubated routinely. As a result, 16 hatching eggs were found non-embryonated, 28 duck embryos died during incubation and 46 newly hatched ducklings were obtained. Vitelline membranes of non-embryonated hatching eggs, vitelline membrane, brain or liver samples of dead embryos and brain samples of newly hatched ducklings were collected for virus detection. Samples collected from one egg, embryo or duckling were treated as one. Consequently, 18 of 35 (51.43%) hatching eggs, 2 of 16 (12.50%) non-embryonated duck eggs, 17 of 28 (60.71%) dead duck embryos and 5 of 46 (10.87%) newly hatched ducklings were detected positive for TMUV using NS3-based RT-PCR. Overall, 42 of 125 (33.6%) eggs were positive for TMUV. A virus strain, designated as TMUV-SDDE, was isolated from one of these dead duck embryos which were detected TMUV positive. The results of phylogenetic analysis showed that E gene of TMUV-SDDE virus was closely related to other TMUV strains isolated in China during 2010-2013. Pathogenicity studies showed that TMUV-SDDE strain was virulent to ducklings. This is the first report that TMUV is isolated from duck embryos. The findings provide evidence of possible vertical transmission of TMUV from breeding ducks to ducklings.
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: Ying
authors.initials: Y
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: Xiuli
authors.initials: X
authors.lastname: Li
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Ti
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Yang
authors.affiliation: Zoology Institute, Agricultural University of Shan Dong Province, Dai Zong Avenue 61, Taian City 271018, Shan Dong Province, China.
authors.forename: Lu
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: Yunjian
authors.initials: Y
authors.lastname: Lu
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: Youxiang
authors.initials: Y
authors.lastname: Diao
mesh_terms: D000818:Animals; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004372:Ducks; D005260:Female; D005416:Flavivirus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D018177:Flavivirus Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D010063:Ovum / Q000821:virology; D010802:Phylogeny; D011201:Poultry Diseases / Q000635:transmission* / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms
chemical_list: D018076:DNA, Complementary; D012367:RNA, Viral
keywords: Duck embryo; Tembusu virus; Vertical transmission