title: Clinical symptoms, immune factors, and molecular characteristics of an adult male in Shenzhen, China infected with influenza virus H5N1.
abstract: 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.
authors.affiliation: Center for Disease Control and Prevention, Shenzhen 518020, China.
authors.forename: Chunli
authors.initials: C
authors.lastname: Wu
authors.forename: Xing
authors.initials: X
authors.lastname: Lu
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Jin
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Cheng
authors.forename: Shisong
authors.initials: S
authors.lastname: Fang
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Wang
authors.forename: Hanwu
authors.initials: H
authors.lastname: Ma
authors.forename: Renli
authors.initials: R
authors.lastname: Zhang
authors.forename: Jinquan
authors.initials: J
authors.lastname: Cheng
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001784:Blood Gas Analysis; D016516:CD4-CD8 Ratio; D002681:China; D016000:Cluster Analysis; D016207:Cytokines / Q000097:blood; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications / Q000276:immunology / Q000473:pathology* / Q000821:virology*; D007958:Leukocyte Count; D008231:Lymphopenia; D008297:Male; D008969:Molecular Sequence Data; D009102:Multiple Organ Failure; D010802:Phylogeny; D010976:Platelet Count; D011024:Pneumonia, Viral / Q000473:pathology / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D016207:Cytokines; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D012367:RNA, Viral