Molecular epidemiology of avian influenza viruses circulating among healthy poultry flocks in farms in northern Vietnam

Takakuwa, Hiroki; Yamashiro, Tetsu; Le, Mai Quynh; Phuong, Lien S.; Ozaki, Hiroichi; Tsunekuni, Ryota; Usui, Tatsufumi; Ito, Hiroshi; Morimatsu, Masami; Tomioka, Y.; Yamaguchi, Tsuyoshi; Ito, Toshihiro; Murase, Toshiyuki; Ono, Etsuro; Otsuki, Koichi

doi:10.1016/j.prevetmed.2011.09.014

Cited by 9 publications

(1 citation statement)

References 26 publications

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“…However, some studies indicate that wild waterfowl can be infected sporadically with H5N1 viruses prevailing in domestic poultry and die on the way back to the nest [Sakoda et al, 2010]. Some studies have shown some healthy poultry, such as domestic ducks and geese, can maintain and transmit the H5N1 viruses [Takakuwa et al, 2012]. Therefore, the new subclade 2.3.2.1 might have originated in poultry and been transmitted by migratory wild birds.…”

Section: Discussionmentioning

confidence: 99%

Clinical symptoms, immune factors, and molecular characteristics of an adult male in Shenzhen, China infected with influenza virus H5N1

Wu¹,

Lü²,

Wang³

et al. 2013

Journal of Medical Virology

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On December 29, 2011, a man infected with a subclade of the H5N1 virus was confirmed in Shenzhen, China. The clinical symptoms and immune factors of the patient were investigated and the phylogenetic and molecular characteristics of the virus were analyzed. High fever, rapid development of serious pneumonia and multi-organ failure were the main clinical symptoms. Arterial blood gas analysis showed that PaCO2 rose sharply and PO2 decreased. Leukocyte and platelet counts decreased rapidly. Peripheral blood lymphocyte counts indicated lymphopenia and inverted ratios of CD4(+) to CD8(+) cells. Cytokine analysis showed that the levels of serum IL-6, IL-10, and IFN-r continued to increase, whereas the levels of IL-12 and TNFs decreased during the clinical course. MCP-1 and IP-10 remained at a high level after infection. Phylogenetic analysis confirmed that the virus A/Shenzhen/1/2011 belongs to the new subclade 2.3.2.1. An Arg (R) insertion at P6 and an RP8I substitution in the HA cleavage site motif were detected in the virus. Compared to the vaccine strain, 16 specific substitutions occurred in the HA1 protein. Some of them were located on the receptor-binding site, glycosylation site and the region of the antigenic determinant. In summary, serious complications and immune system disorders were the main features of the infection with H5N1. Gene variation did not weaken the highly pathogenic features of viruses and the pathogenicity and antigenicity of the new subclade virus were changed.

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Section: Discussionmentioning

confidence: 99%

Clinical symptoms, immune factors, and molecular characteristics of an adult male in Shenzhen, China infected with influenza virus H5N1

Wu¹,

Lü²,

Wang³

et al. 2013

Journal of Medical Virology

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The genetic and antigenic diversity of avian influenza viruses isolated from domestic ducks, muscovy ducks, and chickens in northern and southern Vietnam, 2010–2012

et al. 2013

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To estimate the prevalence of avian influenza virus infection in Vietnam, surveillance was conducted in domestic and wild birds from households, live-bird markets, slaughtering sites, and bird sanctuaries in Vietnam between October 2010 and October 2012. Of the 4,550 samples collected, 226 influenza A virus isolates were obtained from domestic ducks, muscovy ducks, and chickens. Of these, 25 and 22 H5N1 highly pathogenic avian influenza viruses (HPAIVs) were isolated from apparently healthy domestic ducks in live-bird markets and slaughtering sites in northern and southern Vietnam, respectively. The HA genes of H5 viruses isolated from birds in northern Vietnam phylogenetically belonged to the genetic clade 2.3.2.1 and those in southern Vietnam belonged to the genetic clade 1.1. In addition, 39 H3, 12 H4, 1 H5, 93 H6, 2 H7, 18 H9, 3 H10, and 11 H11 viruses were isolated. Phylogenetic and antigenic analyses of the H6 and H9 viruses revealed that they were closely related to the isolates obtained from domestic poultry in China. Phylogenetic analyses of internal gene segments of these isolates revealed that these viruses were circulating in both domestic and wild birds in Asia and reassortment events had occurred frequently. Therefore, it will be important to continue the surveillance and strict controls over the movement and trade of poultry and poultry products in order to eradicate H5N1 HPAIV from Asia.

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Characterization of H3 subtype avian influenza viruses isolated from poultry in Vietnam

et al. 2020

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Molecular epidemiology of avian influenza viruses circulating among healthy poultry flocks in farms in northern Vietnam

Cited by 9 publications

References 26 publications

Clinical symptoms, immune factors, and molecular characteristics of an adult male in Shenzhen, China infected with influenza virus H5N1

Clinical symptoms, immune factors, and molecular characteristics of an adult male in Shenzhen, China infected with influenza virus H5N1

The genetic and antigenic diversity of avian influenza viruses isolated from domestic ducks, muscovy ducks, and chickens in northern and southern Vietnam, 2010–2012

Characterization of H3 subtype avian influenza viruses isolated from poultry in Vietnam

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