title: Comparative Epidemiology of Human Fatal Infections with Novel, High (H5N6 and H5N1) and Low (H7N9 and H9N2) Pathogenicity Avian Influenza A Viruses.
abstract: This study aimed to assess the mortality risks for human infection with high (HPAI) and low (LPAI) pathogenicity avian influenza viruses. The HPAI case fatality rate (CFR) was far higher than the LPAI CFR [66.0% (293/444) vs. 68.75% (11/16) vs. 40.4% (265/656) vs. 0.0% (0/18) in the cases with H5N1, H5N6, H7N9, and H9N2 viruses, respectively;p< 0.001]. Similarly, the CFR of the index cases was greater than the secondary cases with H5N1 [100% (43/43) vs. 43.3% (42/97),p< 0.001]. Old age [22.5 vs. 17 years for H5N1,p= 0.018; 61 vs. 49 years for H7H9,p< 0.001], concurrent diseases [18.8% (15/80) vs. 8.33% (9/108) for H5N1,p= 0.046; 58.6% (156/266) vs. 34.8% (135/388) for H7H9,p< 0.001], delayed confirmation [13 vs. 6 days for H5N1,p< 0.001; 10 vs. 8 days for H7N9,p= 0.011] in the fatalities and survivors, were risk factors for deaths. With regard to the H5N1 clusters, exposure to poultry [67.4% (29/43) vs. 45.2% (19/42),p= 0.039] was the higher risk for the primary than the secondary deaths. In conclusion, old age, comorbidities, delayed confirmation, along with poultry exposure are the major risks contributing to fatal outcomes in human HPAI and LPAI infections.
authors.affiliation: Department of Respiratory Medicine, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China. wuzuqun522@sohu.com.
authors.forename: Zu-Qun
authors.initials: ZQ
authors.lastname: Wu
authors.affiliation: Department of Medicine, Jinxi Petrochemical Hospital, Huludao 125001, China. zgdzy_zgdzy@sina.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: National Research Center for Wildlife Borne Diseases, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China. nazhao2007@163.com.
authors.forename: Na
authors.initials: N
authors.lastname: Zhao
authors.affiliation: Department of Infectious Diseases and Key Lab of Vaccine against Hemorrhagic Fever with Renal Syndrome, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China. zhy@cdc.zj.cn.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Department of Infectious Diseases, Shanghai Municipal Centre for Disease Control and Prevention, Shanghai 200336, China. scdcph@163.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Pan
authors.affiliation: Center for Geographic Information Science, Research Centre for Humanities and Social Science, Academia Sinica, Taipei 115, Taiwan. dachianpig@gmail.com.
authors.forename: Ta-Chien
authors.initials: TC
authors.lastname: Chan
authors.affiliation: School of Public Health, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China. zhangzhiruo@sjtu.edu.cn.
authors.forename: Zhi-Ruo
authors.initials: ZR
authors.lastname: Zhang
authors.affiliation: Department of Infectious Diseases and Key Lab of Vaccine against Hemorrhagic Fever with Renal Syndrome, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China. liushelan@126.com.
authors.forename: She-Lan
authors.initials: SL
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000818:Animals; D001717:Birds; D005260:Female; D006801:Humans; D015994:Incidence; D053124:Influenza A Virus, H5N1 Subtype / Q000472:pathogenicity*; D064766:Influenza A Virus, H7N9 Subtype / Q000472:pathogenicity*; D053127:Influenza A Virus, H9N2 Subtype / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000453:epidemiology / Q000821:virology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000401:mortality / Q000821:virology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012621:Seasons; D014774:Virulence; D055815:Young Adult
keywords: endemic infection; horizontal transmission; influenza virus; seasonal incidence