1
|
Yi Z, Lu G, Chaojian S, Ping L, Renjun Z, Jida L, Yuhai B, Xiaoyan Z, Honglin Y, Quangang X, Yan L, Magalhães RJS, Youming W. Exploring the determinants of influenza A/H7N9 control intervention efficacy in China: disentangling the effect of the "1110" policy and poultry vaccination. Transbound Emerg Dis 2022; 69:e1982-e1991. [PMID: 35332680 DOI: 10.1111/tbed.14532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/23/2022] [Accepted: 03/21/2022] [Indexed: 12/01/2022]
Abstract
: The influenza A virus of the H7N9 subtype (FLUAV H7N9) emerged in Eastern China provinces in 2013 causing illness in both poultry and humans. Most reported FLUAV H7N9 human cases were related to those associated with the live poultry market chain. From 2013 to 2017, there were five epidemic waves of human infections, and from the end of 2016, the number of human cases increased sharply. To control FLUAV H7N9 in the market chain, the so-called "1110" policy at live poultry markets and a national vaccination programme were implemented. The relative efficacy of these two measures on the number of poultry and human infections has not been quantified and compared. To explore their efficacy, a cross-sectional study was conducted in six provinces of China, and the vaccination and surveillance data of H7N9 were analysed. Our survey data showed that poultry vendors were not widely aware of and did not accept the "1110" policy. For subjective and objective factors, some measures of the "1110" policy were not implemented in live bird markets (LBMs). However, the national vaccination programme achieved good immune effects and sharply decreased poultry FLUAV H7N9 infections. The detection rates of FLUAV H7N9 in LBMs and farms gradually decreased since the vaccination programme was implemented. Our analysis also indicated that human infections were closely related to poultry virus carriage rates; therefore, controlling FLUAV H7N9 circulation in poultry was an effective measure to control FLUAV H7N9 infections in humans. Although LBMs play a significant role in human infections, the management measures may not be implemented efficiently; hence, we need to conduct more investigations before developing related policies. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Zhang Yi
- College of public health, Zunyi Medical University, Guizhou Zunyi, China
| | - Gao Lu
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| | - Shen Chaojian
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| | - Liu Ping
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| | - Zhang Renjun
- Center for Animal Disease Control and Prevention of GuiZhou Province, Guizhou Guiyang, China
| | - Li Jida
- College of public health, Zunyi Medical University, Guizhou Zunyi, China
| | - Bi Yuhai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Center for Influenza Research and Early-warning (CASCIRE), Beijing, China
| | - Zhou Xiaoyan
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| | - Yang Honglin
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| | - Xu Quangang
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| | - Li Yan
- College of public health, Zunyi Medical University, Guizhou Zunyi, China
| | - Ricardo J Soares Magalhães
- UQ Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, Gatton Queensland, 4343, Australia.,Children Health and Environment Program, UQ Child Health Research Centre, The University of Queensland, South Brisbane, Queensland, 4101, Australia
| | - Wang Youming
- China Animal Health and Epidemiology Center (CAHEC), Shandong Qingdao, China
| |
Collapse
|
2
|
Chowdhury S, Azziz-Baumgartner E, Kile JC, Hoque MA, Rahman MZ, Hossain ME, Ghosh PK, Ahmed SSU, Kennedy ED, Sturm-Ramirez K, Gurley ES. Association of Biosecurity and Hygiene Practices with Environmental Contamination with Influenza A Viruses in Live Bird Markets, Bangladesh. Emerg Infect Dis 2021; 26:2087-2096. [PMID: 32818393 PMCID: PMC7454050 DOI: 10.3201/eid2609.191029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In Bangladesh, live bird market environments are frequently contaminated with avian influenza viruses. Shop-level biosecurity practices might increase risk for environmental contamination. We sought to determine which shop-level biosecurity practices were associated with environmental contamination. We surveyed 800 poultry shops to describe biosecurity practices and collect environmental samples. Samples from 205 (26%) shops were positive for influenza A viral RNA, 108 (14%) for H9, and 60 (8%) for H5. Shops that slaughtered poultry, kept poultry overnight, remained open without rest days, had uneven muddy floors, held poultry on the floor, and housed sick and healthy poultry together were more frequently positive for influenza A viruses. Reported monthly cleaning seemed protective, but disinfection practices were not otherwise associated with influenza A virus detection. Slaughtering, keeping poultry overnight, weekly rest days, infrastructure, and disinfection practices could be targets for interventions to reduce environmental contamination.
Collapse
|
3
|
Cheng W, Wang X, Shen Y, Yu Z, Liu S, Cai J, Chen E. Comparison of the three waves of avian influenza A(H7N9) virus circulation since live poultry markets were permanently closed in the main urban areas in Zhejiang Province, July 2014-June 2017. Influenza Other Respir Viruses 2019; 12:259-266. [PMID: 29243376 PMCID: PMC5820431 DOI: 10.1111/irv.12532] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The sudden increase in the number of human cases infected with avian influenza A(H7N9) virus after September 2016 raised global concern. OBJECTIVES To assess the changes in epidemiological characteristics of H7N9 cases since the massive closure of live poultry markets (LPMs) in the main urban areas in Zhejiang province. METHODS We used descriptive statistics to compare epidemiological characteristics of the three distinct waves of H7N9 cases in Zhejiang province. The rural or urban cases were defined according to the location where the patients had exposure within 2 weeks before illness onset. RESULTS Between July 2014 and June 2017, 166 H7N9 cases were reported in Zhejiang province, with 45, 34, and 87 cases reported in the third, fourth, and fifth wave, respectively. Across the three waves, most reported cases were from rural areas. A similar percentage of cases in all three waves reported exposure to LPMs, raising poultry at home or around the house, as well as occupational exposure. Compared to the third (80.00%) and fourth wave (70.59%), a significantly larger proportion of cases from the non-LPMs closure areas were observed in the fifth wave (89.66%) (P = .034). CONCLUSION Epidemiological characteristics of human cases infected with avian influenza A(H7N9) virus had generally remained unchanged since the massive closure of LPMs in the main urban area of Zhejiang province. The sudden increase in the number of H7N9 cases in the fifth wave was mainly attributed to the excessive cases reported from areas where LPMs were not permanently closed.
Collapse
Affiliation(s)
- Wei Cheng
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Xiaoxiao Wang
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Ye Shen
- Department of Epidemiology and BiostatisticsUniversity of GeorgiaAthensGAUSA
| | - Zhao Yu
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Shelan Liu
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Jian Cai
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| | - Enfu Chen
- Zhejiang Provincial Centre for Disease Control and PreventionHangzhouChina
| |
Collapse
|
4
|
Zhang ZH, Meng LS, Kong DH, Liu J, Li SZ, Zhou C, Sun J, Song RJ, Wu JJ. A Suspected Person-to-person Transmission of Avian Influenza A (H7N9) Case in Ward. Chin Med J (Engl) 2018; 130:1255-1256. [PMID: 28485329 PMCID: PMC5443035 DOI: 10.4103/0366-6999.205849] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Ze-Hua Zhang
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Ling-Sheng Meng
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - De-Hua Kong
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Jun Liu
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Si-Zhao Li
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Chao Zhou
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Juan Sun
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Ren-Jie Song
- Department of Intensive Care Unit, Anhui No. 2 Provincial People's Hospital, Hefei, Anhui 230041, China
| | - Jin-Ju Wu
- Hefei Center for Disease Control and Prevention, Hefei, Anhui 230061, China
| |
Collapse
|
5
|
de Vries RP, Tzarum N, Peng W, Thompson AJ, Ambepitiya Wickramasinghe IN, de la Pena ATT, van Breemen MJ, Bouwman KM, Zhu X, McBride R, Yu W, Sanders RW, Verheije MH, Wilson IA, Paulson JC. A single mutation in Taiwanese H6N1 influenza hemagglutinin switches binding to human-type receptors. EMBO Mol Med 2018; 9:1314-1325. [PMID: 28694323 PMCID: PMC5582370 DOI: 10.15252/emmm.201707726] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In June 2013, the first case of human infection with an avian H6N1 virus was reported in a Taiwanese woman. Although this was a single non‐fatal case, the virus continues to circulate in Taiwanese poultry. As with any emerging avian virus that infects humans, there is concern that acquisition of human‐type receptor specificity could enable transmission in the human population. Despite mutations in the receptor‐binding pocket of the human H6N1 isolate, it has retained avian‐type (NeuAcα2‐3Gal) receptor specificity. However, we show here that a single nucleotide substitution, resulting in a change from Gly to Asp at position 225 (G225D), completely switches specificity to human‐type (NeuAcα2‐6Gal) receptors. Significantly, G225D H6 loses binding to chicken trachea epithelium and is now able to bind to human tracheal tissue. Structural analysis reveals that Asp225 directly interacts with the penultimate Gal of the human‐type receptor, stabilizing human receptor binding.
Collapse
Affiliation(s)
- Robert P de Vries
- Departments of Molecular Medicine & Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA.,Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands
| | - Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, The Scripps Research Institute, La Jolla, CA, USA
| | - Wenjie Peng
- Departments of Molecular Medicine & Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Andrew J Thompson
- Departments of Molecular Medicine & Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | | | - Alba T Torrents de la Pena
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Marielle J van Breemen
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Kim M Bouwman
- Pathology Division, Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Xueyong Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, The Scripps Research Institute, La Jolla, CA, USA
| | - Ryan McBride
- Departments of Molecular Medicine & Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Wenli Yu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, The Scripps Research Institute, La Jolla, CA, USA
| | - Rogier W Sanders
- Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Microbiology and Immunology, Weil Medical College of Cornell University, New York, NY, USA
| | - Monique H Verheije
- Pathology Division, Department of Pathobiology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, The Scripps Research Institute, La Jolla, CA, USA .,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - James C Paulson
- Departments of Molecular Medicine & Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| |
Collapse
|
6
|
Chen E, Wang MH, He F, Sun R, Cheng W, Zee BCY, Lau SYF, Wang X, Chong KC. An increasing trend of rural infections of human influenza A (H7N9) from 2013 to 2017: A retrospective analysis of patient exposure histories in Zhejiang province, China. PLoS One 2018; 13:e0193052. [PMID: 29447278 PMCID: PMC5814046 DOI: 10.1371/journal.pone.0193052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/02/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Although investigations have shown that closing live poultry markets (LPMs) is highly effective in controlling human influenza A (H7N9) infections, many of the urban LPMs were shut down, but rural LPMs remained open. This study aimed to compare the proportional changes between urban and rural infections in the Zhejiang province from 2013 to 2017 by analyzing the exposure histories of human cases. METHODS All laboratory-confirmed cases of H7N9 from 2013 (the first wave) to 2017 (the fifth wave) in the Zhejiang province of China were analyzed. Urban and rural infections were defined based on the locations of poultry exposure (direct and indirect) in urban areas (central towns) and rural areas (towns and villages on the outskirts of cities). A Chi-square trend test was used to compare the proportional trend between urban and rural infections over time and logistic regression was used to obtain the odds ratio by years. RESULTS From 2013 to 2017, a statistically significant trend in rural infections was observed (p <0.01). The incremental odds ratio by years of rural infections was 1.59 with 95% confidence intervals of 1.34 to 1.86. Each year, significant increases in the proportion of live poultry transactions in LPMS and poultry processing plants were detected in conjunction with an increased proportion of urban and rural infections. CONCLUSION The empirical evidence indicated a need for heightened infection control measures in rural areas, such as serving rural farms and backyards as active surveillance points for the H7N9 virus. Other potential interventions such as the vaccination of poultry and extending the closure of LPMs to the provincial level require further careful investigations.
Collapse
Affiliation(s)
- Enfu Chen
- Zhejiang Provincial Center for Disease Control and Prevention, Binjiang District, Hangzhou, Zhejiang, China
| | - Maggie H. Wang
- School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Fan He
- Zhejiang Provincial Center for Disease Control and Prevention, Binjiang District, Hangzhou, Zhejiang, China
| | - Riyang Sun
- School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Wei Cheng
- Zhejiang Provincial Center for Disease Control and Prevention, Binjiang District, Hangzhou, Zhejiang, China
| | - Benny C. Y. Zee
- School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Steven Y. F. Lau
- School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Xiaoxiao Wang
- Zhejiang Provincial Center for Disease Control and Prevention, Binjiang District, Hangzhou, Zhejiang, China
- * E-mail: (KCC); (XW)
| | - Ka Chun Chong
- School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Clinical Trials and Biostatistics Laboratory, Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
- * E-mail: (KCC); (XW)
| |
Collapse
|
7
|
Pathobiology of Clade 2.3.4.4 H5Nx High-Pathogenicity Avian Influenza Virus Infections in Minor Gallinaceous Poultry Supports Early Backyard Flock Introductions in the Western United States in 2014-2015. J Virol 2017; 91:JVI.00960-17. [PMID: 28794040 DOI: 10.1128/jvi.00960-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 08/04/2017] [Indexed: 11/20/2022] Open
Abstract
In 2014 and 2015, the United States experienced an unprecedented outbreak of Eurasian clade 2.3.4.4 H5 highly pathogenic avian influenza (HPAI) virus. Initial cases affected mainly wild birds and mixed backyard poultry species, while later outbreaks affected mostly commercial chickens and turkeys. The pathogenesis, transmission, and intrahost evolutionary dynamics of initial Eurasian H5N8 and reassortant H5N2 clade 2.3.4.4 HPAI viruses in the United States were investigated in minor gallinaceous poultry species (i.e., species for which the U.S. commercial industries are small), namely, Japanese quail, bobwhite quail, pearl guinea fowl, chukar partridges, and ring-necked pheasants. Low mean bird infectious doses (<2 to 3.7 log10) support direct introduction and infection of these species as observed in mixed backyard poultry during the early outbreaks. Pathobiological features and systemic virus replication in all species tested were consistent with HPAI virus infection. Sustained virus shedding with transmission to contact-exposed birds, alongside long incubation periods, may enable unrecognized dissemination and adaptation to other gallinaceous species, such as chickens and turkeys. Genome sequencing of excreted viruses revealed numerous low-frequency polymorphisms and 20 consensus-level substitutions in all genes and species, but especially in Japanese quail and pearl guinea fowl and in internal proteins PB1 and PB2. This genomic flexibility after only one passage indicates that influenza viruses can continue to evolve in galliform species, increasing their opportunity to adapt to other species. Our findings suggest that these gallinaceous poultry are permissive for infection and sustainable transmissibility with the 2014 initial wild bird-adapted clade 2.3.4.4 virus, with potential acquisition of mutations leading to host range adaptation.IMPORTANCE The outbreak of clade 2.3.4.4 H5 highly pathogenic avian influenza (HPAI) virus that occurred in the United States in 2014 and 2015 represents the worst livestock disease event in the country, with unprecedented socioeconomic and commercial consequences. Epidemiological and molecular investigations can identify transmission pathways of the HPAI virus. However, understanding the pathogenesis, transmission, and intrahost evolutionary dynamics of new HPAI viruses in different avian species is paramount. The significance of our research is in examining the susceptibility of minor gallinaceous species to HPAI virus, as this poultry sector also suffers from HPAI epizootics, and identifying the biological potential of these species as an epidemiological link between the waterfowl reservoir and the commercial chicken and turkey populations, with the ultimate goal of refining surveillance in these populations to enhance early detection, management, and control in future HPAI virus outbreaks.
Collapse
|
8
|
Ma W, Huang H, Chen J, Xu K, Dai Q, Yu H, Deng F, Qi X, Wang S, Hong J, Bao C, Huo X, Zhou M. Predictors for fatal human infections with avian H7N9 influenza, evidence from four epidemic waves in Jiangsu Province, Eastern China, 2013-2016. Influenza Other Respir Viruses 2017; 11:418-424. [PMID: 28675634 PMCID: PMC5596522 DOI: 10.1111/irv.12461] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2017] [Indexed: 01/13/2023] Open
Abstract
Background Four epidemic waves of human infection with H7N9 have been recorded in China up to 1 June 2016, including in Jiangsu Province. However, few studies have investigated the differences in patients' characteristics among the four epidemic waves, and the analyses of factors associated with fatal infection lacked statistical power in previous studies due to limited sample size. Methods All laboratory‐confirmed A(H7N9) patients in Jiangsu province were analysed. Patients' characteristics were compared across four waves and between survivors and those who died. Multivariate analyses were used to identify independent predictors of death. Results Significant differences were found in the lengths of several time intervals (from onset of disease to laboratory confirmation, to onset of ARDS and respiratory failure, and to death) and in the development of heart failure. The proportions of overweight patients and rural patients increased significantly across the four waves. Administration of glucocorticoids and double‐dose neuraminidase inhibitors became the norm. Predictors of death included complications such as ARDS, heart failure and septic shock, administration of glucocorticoids, and disease duration. Conclusion Characteristics of H7N9 patients and clinical treatment options changed over time. Particular complications and the use of particular treatment, along with disease duration, could help clinicians predict the outcome of H7N9 infections.
Collapse
Affiliation(s)
- Wang Ma
- School of Public Health, Nanjing Medical University, Nanjing, China
| | - Haodi Huang
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Jian Chen
- School of Public Health, Wannan Medical College, Wannan, China
| | - Ke Xu
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Qigang Dai
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Huiyan Yu
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Fei Deng
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Xian Qi
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Shenjiao Wang
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Jie Hong
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Changjun Bao
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Xiang Huo
- Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| | - Minghao Zhou
- School of Public Health, Nanjing Medical University, Nanjing, China.,Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China
| |
Collapse
|
9
|
Abstract
OBJECTIVE This study aims to discuss the correlation between daily reported H7N9 cases and stock price indices in China. METHODS Information on daily reported H7N9 cases and stock market sectors indices between February 19, 2013 and March 31, 2014 were collected. A distributed lag non-linear model was used to describe the variation trend for the stock indices. RESULTS The daily reported number of H7N9 cases was associated with the closing price of the Avian Influenza Sector Index (P < 0.05) and the opening price of the Shanghai Composite Index (P = 0.029). The Avian Influenza Sector Index decreased with increasing of daily reported case number when daily reported cases ≤ 4. Case number was associated with the opening/closing price of the Chinese Traditional Medicine Sector Index, the Biological Product Sector Index, and the Biomedicine Sector Index (P < 0.05). CONCLUSION New or reemerging infectious diseases epidemic cause economic loss which is reflected in movements in stock prices.
Collapse
|
10
|
Lu L, Leigh Brown AJ, Lycett SJ. Quantifying predictors for the spatial diffusion of avian influenza virus in China. BMC Evol Biol 2017; 17:16. [PMID: 28086751 PMCID: PMC5237338 DOI: 10.1186/s12862-016-0845-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 12/08/2016] [Indexed: 11/18/2022] Open
Abstract
Background Avian influenza virus (AIV) causes both severe outbreaks and endemic disease among poultry and has caused sporadic human infections in Asia, furthermore the routes of transmission in avian species between geographic regions can be numerous and complex. Using nucleotide sequences from the internal protein coding segments of AIV, we performed a Bayesian phylogeographic study to uncover regional routes of transmission and factors predictive of the rate of viral diffusion within China. Results We found that the Central area and Pan-Pearl River Delta were the two main sources of AIV diffusion, while the East Coast areas especially the Yangtze River delta, were the major targets of viral invasion. Next we investigated the extent to which economic, agricultural, environmental and climatic regional data was predictive of viral diffusion by fitting phylogeographic discrete trait models using generalised linear models. Conclusions Our results highlighted that the economic-agricultural predictors, especially the poultry population density and the number of farm product markets, are the key determinants of spatial diffusion of AIV in China; high human density and freight transportation are also important predictors of high rates of viral transmission; Climate features (e.g. temperature) were correlated to the viral invasion in the destination to some degree; while little or no impacts were found from natural environment factors (such as surface water coverage). This study uncovers the risk factors and enhances our understanding of the spatial dynamics of AIV in bird populations. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0845-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lu Lu
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh, Edinburgh, EH9 3JT, UK
| | - Andrew J Leigh Brown
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh, Edinburgh, EH9 3JT, UK
| | - Samantha J Lycett
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK.
| |
Collapse
|
11
|
Offeddu V, Cowling BJ, Peiris JM. Interventions in live poultry markets for the control of avian influenza: a systematic review. One Health 2016; 2:55-64. [PMID: 27213177 PMCID: PMC4871622 DOI: 10.1016/j.onehlt.2016.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 02/17/2016] [Accepted: 03/14/2016] [Indexed: 11/19/2022] Open
Abstract
Background Live poultry markets (LPMs) pose a threat to public health by promoting the amplification and dissemination of avian influenza viruses (AIVs) and by providing the ideal setting for zoonotic influenza transmission. Objective This review assessed the impact of different interventions implemented in LPMs to control the emergence of zoonotic influenza. Methods Publications were identified through a systematic literature search in the PubMed, MEDLINE and Web of Science databases. Eligible studies assessed the impact of different interventions, such as temporary market closure or a ban on holding poultry overnight, in reducing i) AIV-detection rates in birds and the market environment or ii) influenza incidence in humans. Unpublished literature, reviews, editorials, cross-sectional studies, theoretical models and publications in languages other than English were excluded. Relevant findings were extracted and critically evaluated. For the comparative analysis of findings across studies, standardized outcome measures were computed as i) the relative risk reduction (RRR) of AIV-detection in LPMs and ii) incidence rate ratios (IRRs) of H7N9-incidence in humans. Results A total of 16 publications were identified and reviewed. Collectively, the data suggest that AIV-circulation can be significantly reduced in the LPM-environment and among market-birds through (i) temporary LPM closure, (ii) periodic rest days (iii) market depopulation overnight and (iv) improved hygiene and disinfection. Overall, the findings indicate that the length of stay of poultry in the market is a critical control point to interrupt the AIV-replication cycle within LPMs. In addition, temporary LPM closure was associated with a significant reduction of the incidence of zoonotic influenza. The interpretation of these findings is limited by variations in the implementation of interventions. In addition, some of the included studies were of ecologic nature or lacked an inferential framework, which might have lead to cosiderable confounding and bias. Conclusions The evidence collected in this review endorses permanent LPM-closure as a long-term objective to reduce the zoonotic risk of avian influenza, although its economic and socio-political implications favour less drastic interventions, e.g. weekly rest days, for implementation in the short-term. •Avian influenza viruses (AIVs) can infect humans. Bird-to-human transmission is particularly intense in live poultry markets. •Periodic rest days, overnight depopulation or sale bans of certain species significantly reduce AIV-circulation in the markets. •Market closure would lastingly reduce the risk of animal and human infection.
Collapse
Key Words
- influenza a virus
- live poultry market
- a/h7n9
- a/h9n2
- closure
- rest day
- c/d, cleansing and disinfection
- glm, general linear model
- irr, incidence rate ratio
- lbm, live bird market
- lpm, live poultry market
- ndv, newcastle disease virus
- or, odds ratio
- pue, pneumonia of unknown etiology
- rlpm, retail live poultry market
- rr, relative risk
- rrr, relative risk reduction
- rt-pcr, reverse transcription polymerase chain reaction
- wlpm, wholesale live poultry market
Collapse
Affiliation(s)
- Vittoria Offeddu
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Benjamin J. Cowling
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - J.S. Malik Peiris
- WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
- Centre of Influenza Research, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| |
Collapse
|
12
|
Yuan J, Lau EH, Li K, Leung YC, Yang Z, Xie C, Liu Y, Liu Y, Ma X, Liu J, Li X, Chen K, Luo L, Di B, Cowling BJ, Tang X, Leung GM, Wang M, Peiris M. Effect of Live Poultry Market Closure on Avian Influenza A(H7N9) Virus Activity in Guangzhou, China, 2014. Emerg Infect Dis 2016; 21:1784-93. [PMID: 26402310 PMCID: PMC4593444 DOI: 10.3201/eid2110.150623] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Temporary closure and disinfection can rapidly reduce levels of infectious virus in these settings. We assessed the effect of closing live poultry markets in China on influenza A(H7N9) virus detection and viability. Intensive sampling was carried out before, during, and after a 2-week citywide market closure; the markets were cleaned and disinfected at the beginning of the closure period. Swab samples were collected at different sites within the markets and tested for H7N9 by real-time reverse transcription PCR and culture. During the closure, H7N9 viral RNA detection and isolation rates in retail markets decreased by 79% (95% CI 64%–88%) and 92% (95% CI 58%–98%), respectively. However, viable H7N9 virus could be cultured from wastewater samples collected up to 2 days after the market closure began. Our findings indicates that poultry workers and the general population are constantly exposed to H7N9 virus at these markets and that market closure and disinfection rapidly reduces the amount of viable virus.
Collapse
|
13
|
Gerloff NA, Khan SU, Zanders N, Balish A, Haider N, Islam A, Chowdhury S, Rahman MZ, Haque A, Hosseini P, Gurley ES, Luby SP, Wentworth DE, Donis RO, Sturm-Ramirez K, Davis CT. Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh. PLoS One 2016; 11:e0152131. [PMID: 27010791 PMCID: PMC4806916 DOI: 10.1371/journal.pone.0152131] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/09/2016] [Indexed: 12/01/2022] Open
Abstract
Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year timeframe of sampling, indicate a continuous circulation of these viruses in the country.
Collapse
Affiliation(s)
- Nancy A. Gerloff
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
| | - Salah Uddin Khan
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Natosha Zanders
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
| | - Amanda Balish
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
| | - Najmul Haider
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Ausraful Islam
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Sukanta Chowdhury
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Mahmudur Ziaur Rahman
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Ainul Haque
- Department of Livestock Services, Ministry of Fisheries and Livestock, Dhaka, Bangladesh
| | | | - Emily S. Gurley
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Stephen P. Luby
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - David E. Wentworth
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
| | - Ruben O. Donis
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
| | - Katharine Sturm-Ramirez
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - C. Todd Davis
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA 30333, United States of America
| |
Collapse
|
14
|
Kucharski AJ, Mills HL, Donnelly CA, Riley S. Transmission Potential of Influenza A(H7N9) Virus, China, 2013-2014. Emerg Infect Dis 2016; 21:852-5. [PMID: 25897624 PMCID: PMC4412215 DOI: 10.3201/eid2105.141137] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
To determine transmission potential of influenza A(H7N9) virus, we used symptom onset data to compare 2 waves of infection in China during 2013–2014. We found evidence of increased transmission potential in the second wave and showed that live bird market closure was significantly less effective in Guangdong than in other regions.
Collapse
|
15
|
Zaraket H, Baranovich T, Kaplan BS, Carter R, Song MS, Paulson JC, Rehg JE, Bahl J, Crumpton JC, Seiler J, Edmonson M, Wu G, Karlsson E, Fabrizio T, Zhu H, Guan Y, Husain M, Schultz-Cherry S, Krauss S, McBride R, Webster RG, Govorkova EA, Zhang J, Russell CJ, Webby RJ. Mammalian adaptation of influenza A(H7N9) virus is limited by a narrow genetic bottleneck. Nat Commun 2015; 6:6553. [PMID: 25850788 PMCID: PMC4403340 DOI: 10.1038/ncomms7553] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 02/06/2015] [Indexed: 02/05/2023] Open
Abstract
Human infection with avian influenza A(H7N9) virus is associated mainly with the exposure to infected poultry. The factors that allow interspecies transmission but limit human-to-human transmission are unknown. Here we show that A/Anhui/1/2013(H7N9) influenza virus infection of chickens (natural hosts) is asymptomatic and that it generates a high genetic diversity. In contrast, diversity is tightly restricted in infected ferrets, limiting further adaptation to a fully transmissible form. Airborne transmission in ferrets is accompanied by the mutations in PB1, NP and NA genes that reduce viral polymerase and neuraminidase activity. Therefore, while A(H7N9) virus can infect mammals, further adaptation appears to incur a fitness cost. Our results reveal that a tight genetic bottleneck during avian-to-mammalian transmission is a limiting factor in A(H7N9) influenza virus adaptation to mammals. This previously unrecognized biological mechanism limiting species jumps provides a measure of adaptive potential and may serve as a risk assessment tool for pandemic preparedness.
Collapse
Affiliation(s)
- Hassan Zaraket
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, PO Box 11-0236 Riad El Solh, Beirut 1107 2020, Lebanon
| | - Tatiana Baranovich
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Bryan S. Kaplan
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Robert Carter
- Department of Computation Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Min-Suk Song
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - James C. Paulson
- Departments of Cell and Molecular Biology and Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, MEM-L71, La Jolla, California 92037, USA
| | - Jerold E. Rehg
- Department of Pathology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Justin Bahl
- School of Public Health, The University of Texas Health Science Center at Houston, 1200 Pressler Street, Houston Texas 77030 USA
| | - Jeri C. Crumpton
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Jon Seiler
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Michael Edmonson
- Department of Computation Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Gang Wu
- Department of Computation Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Erik Karlsson
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Thomas Fabrizio
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Huachen Zhu
- Joint Influenza Research Center (Shantou University Medical College & Hong Kong University), Shantou University Medical College, Shantou, Guangdong 515031, PR China
| | - Yi Guan
- Joint Influenza Research Center (Shantou University Medical College & Hong Kong University), Shantou University Medical College, Shantou, Guangdong 515031, PR China
| | - Matloob Husain
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Stacey Schultz-Cherry
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Scott Krauss
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Ryan McBride
- Departments of Cell and Molecular Biology and Chemical Physiology, The Scripps Research Institute, 10550 North Torrey Pines Road, MEM-L71, La Jolla, California 92037, USA
| | - Robert G. Webster
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Elena A. Govorkova
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Jinghui Zhang
- Department of Computation Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
| | - Charles J. Russell
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
- Department of Microbiology, Immunology & Biochemistry, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| | - Richard J. Webby
- Department of Infectious Diseases, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, Tennessee 38105-3678, USA
- Department of Microbiology, Immunology & Biochemistry, College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
| |
Collapse
|
16
|
Tan KX, Jacob SA, Chan KG, Lee LH. An overview of the characteristics of the novel avian influenza A H7N9 virus in humans. Front Microbiol 2015; 6:140. [PMID: 25798131 PMCID: PMC4350415 DOI: 10.3389/fmicb.2015.00140] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 02/06/2015] [Indexed: 01/05/2023] Open
Abstract
The novel avian influenza A H7N9 virus which caused the first human infection in Shanghai, China; was reported on the 31st of March 2013 before spreading rapidly to other Chinese provinces and municipal cities. This is the first time the low pathogenic avian influenza A virus has caused human infections and deaths; with cases of severe respiratory disease with pneumonia being reported. There were 440 confirmed cases with 122 fatalities by 16 May 2014; with a fatality risk of ∼28%. The median age of patients was 61 years with a male-to-female ratio of 2.4:1. The main source of infection was identified as exposure to poultry and there is so far no definitive evidence of sustained person-to-person transmission. The neuraminidase inhibitors, namely oseltamivir, zanamivir, and peramivir; have shown good efficacy in the management of the novel H7N9 virus. Treatment is recommended for all hospitalized patients, and for confirmed and probable outpatient cases; and should ideally be initiated within 48 h of the onset of illness for the best outcome. Phylogenetic analysis found that the novel H7N9 virus is avian in origin and evolved from multiple reassortments of at least four origins. Indeed the novel H7N9 virus acquired human adaptation via mutations in its eight RNA gene segments. Enhanced surveillance and effective global control are essential to prevent pandemic outbreaks of the novel H7N9 virus.
Collapse
Affiliation(s)
- Kei-Xian Tan
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University MalaysiaBandar Sunway, Malaysia
| | - Sabrina A. Jacob
- School of Pharmacy, Monash University MalaysiaBandar Sunway, Malaysia
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of MalayaKuala Lumpur, Malaysia
| | - Learn-Han Lee
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University MalaysiaBandar Sunway, Malaysia
| |
Collapse
|
17
|
Spackman E, Pantin-Jackwood M, Swayne DE, Suarez DL, Kapczynski DR. Impact of route of exposure and challenge dose on the pathogenesis of H7N9 low pathogenicity avian influenza virus in chickens. Virology 2015; 477:72-81. [PMID: 25662310 PMCID: PMC4359631 DOI: 10.1016/j.virol.2015.01.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/06/2015] [Accepted: 01/14/2015] [Indexed: 12/01/2022]
Abstract
H7N9 influenza A first caused human infections in early 2013 in China. Virus genetics, histories of patient exposures to poultry, and previous experimental studies suggest the source of the virus is a domestic avian species, such as chickens. In order to better understand the ecology of this H7N9 in chickens, we evaluated the infectious dose and pathogenesis of A/Anhui/1/2013 H7N9 in two common breeds of chickens, White Leghorns (table-egg layers) and White Plymouth Rocks (meat chickens). No morbidity or mortality were observed with doses of 10(6) or 10(8)EID50/bird when administered by the upper-respiratory route, and the mean infectious dose (10(6) EID50) was higher than expected, suggesting that the virus is poorly adapted to chickens. Virus was shed at higher titers and spread to the kidneys in chickens inoculated by the intravenous route. Challenge experiments with three other human-origin H7N9 viruses showed a similar pattern of virus replication.
Collapse
Affiliation(s)
- Erica Spackman
- Southeast Poultry Research Laboratory, USDA-Agricultural Research Service, 934 College Station Rd., Athens, GA 30605, USA.
| | - Mary Pantin-Jackwood
- Southeast Poultry Research Laboratory, USDA-Agricultural Research Service, 934 College Station Rd., Athens, GA 30605, USA.
| | - David E Swayne
- Southeast Poultry Research Laboratory, USDA-Agricultural Research Service, 934 College Station Rd., Athens, GA 30605, USA.
| | - David L Suarez
- Southeast Poultry Research Laboratory, USDA-Agricultural Research Service, 934 College Station Rd., Athens, GA 30605, USA.
| | - Darrell R Kapczynski
- Southeast Poultry Research Laboratory, USDA-Agricultural Research Service, 934 College Station Rd., Athens, GA 30605, USA.
| |
Collapse
|
18
|
Zhang Y, Shen Z, Ma C, Jiang C, Feng C, Shankar N, Yang P, Sun W, Wang Q. Cluster of human infections with avian influenza A (H7N9) cases: a temporal and spatial analysis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:816-28. [PMID: 25599373 PMCID: PMC4306894 DOI: 10.3390/ijerph120100816] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/07/2015] [Indexed: 12/03/2022]
Abstract
Objectives: This study aims to describe the spatial and temporal characteristics of human infections with H7N9 virus in China using data from February 2013 to March 2014 from the websites of every province’s Population and Family Planning Commission. Methods: A human infection with H7N9 virus dataset was summarized by county to analyze its spatial clustering, and by date of illness onset to analyze its space-time clustering using the ESRI® Geographic Information System (GIS) software ArcMap™ 10.1 and SatScan. Results: Based on active surveillance data, the distribution map of H7N9 cases shows that compared to the rest of China, the areas from near the Yangtze River delta (YRD) to farther south around the Pearl River delta (PRD) had the highest densities of H7N9 cases. The case data shows a strong space-time clustering in the areas on and near the YRD from 26 March to 18 April 2013 and a weak space-time clustering only in the areas on and near the PRD between 3 and 4 February 2014. However, for the rest of the study period, H7N9 cases were spatial-temporally randomly distributed. Conclusions: Our results suggested that the spatial-temporal clustering of H7N9 in China between 2013 and 2014 is fundamentally different.
Collapse
Affiliation(s)
- Yi Zhang
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| | - Zhixiong Shen
- Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA 70118, USA.
| | - Chunna Ma
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| | - Chengsheng Jiang
- Maryland Institute for Applied Environmental Health, School of Public Health in University of Maryland, College Park, MD 20742, USA.
| | - Cindy Feng
- School of Public Health & The Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Nivedita Shankar
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
| | - Peng Yang
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| | - Wenjie Sun
- School of Food Science, Guangdong Pharmaceutical University, Zhongshan 528458, China.
| | - Quanyi Wang
- Beijing Center for Disease Prevention and Control (CDC), Beijing 100013, China.
| |
Collapse
|
19
|
Watanabe T, Watanabe S, Maher EA, Neumann G, Kawaoka Y. Pandemic potential of avian influenza A (H7N9) viruses. Trends Microbiol 2014; 22:623-31. [PMID: 25264312 DOI: 10.1016/j.tim.2014.08.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/21/2014] [Accepted: 08/26/2014] [Indexed: 12/30/2022]
Abstract
Avian influenza viruses rarely infect humans, but the recently emerged avian H7N9 influenza viruses have caused sporadic infections in humans in China, resulting in 440 confirmed cases with 122 fatalities as of 16 May 2014. In addition, epidemiologic surveys suggest that there have been asymptomatic or mild human infections with H7N9 viruses. These viruses replicate efficiently in mammals, show limited transmissibility in ferrets and guinea pigs, and possess mammalian-adapting amino acid changes that likely contribute to their ability to infect mammals. In this review, we summarize the characteristic features of the novel H7N9 viruses and assess their pandemic potential.
Collapse
Affiliation(s)
- Tokiko Watanabe
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 575 Science Drive, Madison, WI 53711, USA; ERATO Infection-Induced Host Responses Project, Japan Science and Technology Agency, Saitama 332-0012, Japan; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Shinji Watanabe
- ERATO Infection-Induced Host Responses Project, Japan Science and Technology Agency, Saitama 332-0012, Japan; Laboratory of Veterinary Microbiology, Department of Veterinary Sciences, University of Miyazaki, Miyazaki, 889-2192, Japan
| | - Eileen A Maher
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 575 Science Drive, Madison, WI 53711, USA
| | - Gabriele Neumann
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 575 Science Drive, Madison, WI 53711, USA
| | - Yoshihiro Kawaoka
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 575 Science Drive, Madison, WI 53711, USA; ERATO Infection-Induced Host Responses Project, Japan Science and Technology Agency, Saitama 332-0012, Japan; Division of Virology, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan; Department of Special Pathogens, International Research Center for Infectious Diseases, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan.
| |
Collapse
|
20
|
Abstract
Pathogens such as MERS-CoV, influenza A/H5N1 and influenza A/H7N9 are currently generating sporadic clusters of spillover human cases from animal reservoirs. The lack of a clear human epidemic suggests that the basic reproductive number R0 is below or very close to one for all three infections. However, robust cluster-based estimates for low R0 values are still desirable so as to help prioritise scarce resources between different emerging infections and to detect significant changes between clusters and over time. We developed an inferential transmission model capable of distinguishing the signal of human-to-human transmission from the background noise of direct spillover transmission (e.g. from markets or farms). By simulation, we showed that our approach could obtain unbiased estimates of R0, even when the temporal trend in spillover exposure was not fully known, so long as the serial interval of the infection and the timing of a sudden drop in spillover exposure were known (e.g. day of market closure). Applying our method to data from the three largest outbreaks of influenza A/H7N9 outbreak in China in 2013, we found evidence that human-to-human transmission accounted for 13% (95% credible interval 1%–32%) of cases overall. We estimated R0 for the three clusters to be: 0.19 in Shanghai (0.01-0.49), 0.29 in Jiangsu (0.03-0.73); and 0.03 in Zhejiang (0.00-0.22). If a reliable temporal trend for the spillover hazard could be estimated, for example by implementing widespread routine sampling in sentinel markets, it should be possible to estimate sub-critical values of R0 even more accurately. Should a similar strain emerge with R0>1, these methods could give a real-time indication that sustained transmission is occurring with well-characterised uncertainty.
Collapse
|
21
|
Yu H, Wu JT, Cowling BJ, Liao Q, Fang VJ, Zhou S, Wu P, Zhou H, Lau EHY, Guo D, Ni MY, Peng Z, Feng L, Jiang H, Luo H, Li Q, Feng Z, Wang Y, Yang W, Leung GM. Effect of closure of live poultry markets on poultry-to-person transmission of avian influenza A H7N9 virus: an ecological study. Lancet 2014; 383:541-8. [PMID: 24183056 PMCID: PMC3946250 DOI: 10.1016/s0140-6736(13)61904-2] [Citation(s) in RCA: 207] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Transmission of the novel avian influenza A H7N9 virus seems to be predominantly between poultry and people. In the major Chinese cities of Shanghai, Hangzhou, Huzhou, and Nanjing--where most human cases of infection have occurred--live poultry markets (LPMs) were closed in April, 2013, soon after the initial outbreak, as a precautionary public health measure. Our objective was to quantify the effect of LPM closure in these cities on poultry-to-person transmission of avian influenza A H7N9 virus. METHODS We obtained information about every laboratory-confirmed human case of avian influenza A H7N9 virus infection reported in the four cities by June 7, 2013, from a database built by the Chinese Center for Disease Control and Prevention. We used data for age, sex, location, residence type (rural or urban area), and dates of illness onset. We obtained information about LPMs from official sources. We constructed a statistical model to explain the patterns in incidence of cases reported in each city on the basis of the assumption of a constant force of infection before LPM closure, and a different constant force of infection after closure. We fitted the model with Markov chain Monte Carlo methods. FINDINGS 85 human cases of avian influenza A H7N9 virus infection were reported in Shanghai, Hangzhou, Huzhou, and Nanjing by June 7, 2013, of which 60 were included in our main analysis. Closure of LPMs reduced the mean daily number of infections by 99% (95% credibility interval 93-100%) in Shanghai, by 99% (92-100%) in Hangzhou, by 97% (68-100%) in Huzhou, and by 97% (81-100%) in Nanjing. Because LPMs were the predominant source of exposure to avian influenza A H7N9 virus for confirmed cases in these cities, we estimated that the mean incubation period was 3·3 days (1·4-5·7). INTERPRETATION LPM closures were effective in the control of human risk of avian influenza A H7N9 virus infection in the spring of 2013. In the short term, LPM closure should be rapidly implemented in areas where the virus is identified in live poultry or people. In the long term, evidence-based discussions and deliberations about the role of market rest days and central slaughtering of all live poultry should be renewed. FUNDING Ministry of Science and Technology, China; Research Fund for the Control of Infectious Disease; Hong Kong University Grants Committee; China-US Collaborative Program on Emerging and Re-emerging Infectious Diseases; Harvard Center for Communicable Disease Dynamics; and the US National Institutes of Health.
Collapse
Affiliation(s)
- Hongjie Yu
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Joseph T Wu
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Benjamin J Cowling
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
| | - Qiaohong Liao
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Vicky J Fang
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Sheng Zhou
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Peng Wu
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Hang Zhou
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Eric H Y Lau
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Danhuai Guo
- Scientific Data Center, Computer Network Information Center, Chinese Academy of Sciences, Beijing, China
| | - Michael Y Ni
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Zhibin Peng
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Luzhao Feng
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hui Jiang
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Huiming Luo
- National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qun Li
- Public Health Emergency Center, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zijian Feng
- Public Health Emergency Center, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yu Wang
- Office of the Director, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Weizhong Yang
- Office of the Director, Chinese Center for Disease Control and Prevention, Beijing, China.
| | - Gabriel M Leung
- Division of Epidemiology and Biostatistics, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| |
Collapse
|
22
|
Gabbard JD, Dlugolenski D, Van Riel D, Marshall N, Galloway SE, Howerth EW, Campbell PJ, Jones C, Johnson S, Byrd-Leotis L, Steinhauer DA, Kuiken T, Tompkins SM, Tripp R, Lowen AC, Steel J. Novel H7N9 influenza virus shows low infectious dose, high growth rate, and efficient contact transmission in the guinea pig model. J Virol 2014; 88:1502-12. [PMID: 24227867 PMCID: PMC3911619 DOI: 10.1128/jvi.02959-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 11/06/2013] [Indexed: 12/31/2022] Open
Abstract
The zoonotic outbreak of H7N9 subtype avian influenza virus that occurred in eastern China in the spring of 2013 resulted in 135 confirmed human cases, 44 of which were lethal. Sequencing of the viral genome revealed a number of molecular signatures associated with virulence or transmission in mammals. We report here that, in the guinea pig model, a human isolate of novel H7N9 influenza virus, A/Anhui/1/2013 (An/13), is highly dissimilar to an H7N1 avian isolate and instead behaves similarly to a human seasonal strain in several respects. An/13 was found to have a low 50% infectious dose, grow to high titers in the upper respiratory tract, and transmit efficiently among cocaged guinea pigs. The pH of fusion of the hemagglutinin (HA) and the binding of virus to fixed guinea pig tissues were also examined. The An/13 HA displayed a relatively elevated pH of fusion characteristic of many avian strains, and An/13 resembled avian viruses in terms of attachment to tissues. One important difference was seen between An/13 and both the H3N2 human and the H7N1 avian viruses: when inoculated intranasally at a high dose, only the An/13 virus led to productive infection of the lower respiratory tract of guinea pigs. In sum, An/13 was found to retain fusion and attachment properties of an avian influenza virus but displayed robust growth and contact transmission in the guinea pig model atypical of avian strains and indicative of mammalian adaptation.
Collapse
MESH Headings
- Animals
- Disease Models, Animal
- Female
- Guinea Pigs
- Humans
- Influenza A Virus, H3N2 Subtype/genetics
- Influenza A Virus, H3N2 Subtype/physiology
- Influenza A Virus, H7N1 Subtype/genetics
- Influenza A Virus, H7N1 Subtype/physiology
- Influenza A Virus, H7N9 Subtype/genetics
- Influenza A Virus, H7N9 Subtype/growth & development
- Influenza A Virus, H7N9 Subtype/pathogenicity
- Influenza A Virus, H7N9 Subtype/physiology
- Influenza, Human/transmission
- Influenza, Human/virology
- Virulence
Collapse
Affiliation(s)
- Jon D. Gabbard
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Daniel Dlugolenski
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Debby Van Riel
- Department of Viroscience, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Nicolle Marshall
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Summer E. Galloway
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Patricia J. Campbell
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Cheryl Jones
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Scott Johnson
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Lauren Byrd-Leotis
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - David A. Steinhauer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Thijs Kuiken
- Department of Viroscience, Erasmus Medical Center, Rotterdam, The Netherlands
| | - S. Mark Tompkins
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Ralph Tripp
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, USA
| | - Anice C. Lowen
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - John Steel
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA
| |
Collapse
|
23
|
Wu YL, Shen LW, Ding YP, Tanaka Y, Zhang W. Preliminary success in the characterization and management of a sudden breakout of a novel H7N9 influenza A virus. Int J Biol Sci 2014; 10:109-18. [PMID: 24520209 PMCID: PMC3920865 DOI: 10.7150/ijbs.8198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 12/05/2013] [Indexed: 12/21/2022] Open
Abstract
Influenza has always been one of the major threats to human health. The Spanish influenza in 1918, the pandemic influenza A/H1N1 in 2009, and the avian influenza A/H5N1 have brought about great disasters or losses to mankind. More recently, a novel avian influenza A/H7N9 broke out in China and until December 2, 2013, it had caused 139 cases of infection, including 45 deaths. Its risk and pandemic potential attract worldwide attention. In this article, we summarize epidemiology, virology characteristics, clinical symptoms, diagnosis methods, clinical treatment and preventive measures about the avian influenza A/H7N9 virus infection to provide a reference for a possible next wave of flu outbreak.
Collapse
Affiliation(s)
- Yan-Ling Wu
- 1. Lab of Molecular Immunology, Virus Inspection Department, Zhejiang Provincial Center for Disease Control and Prevention, 630 Xincheng Road, Hangzhou, 310051, PR China
| | - Li-Wen Shen
- 2. Lab of Chemical Biology and Molecular Drug Design, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, PR China
| | - Yan-Ping Ding
- 1. Lab of Molecular Immunology, Virus Inspection Department, Zhejiang Provincial Center for Disease Control and Prevention, 630 Xincheng Road, Hangzhou, 310051, PR China
- 2. Lab of Chemical Biology and Molecular Drug Design, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, PR China
| | - Yoshimasa Tanaka
- 3. Center for Innovation in Immunoregulative Technology and Therapeutics, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Wen Zhang
- 2. Lab of Chemical Biology and Molecular Drug Design, College of Pharmaceutical Science, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, PR China
| |
Collapse
|
24
|
Yiu Lai K, Wing Yiu Ng G, Fai Wong K, Fan Ngai Hung I, Kam Fai Hong J, Fan Cheng F, Kwok Cheung Chan J. Human H7N9 avian influenza virus infection: a review and pandemic risk assessment. Emerg Microbes Infect 2013; 2:e48. [PMID: 26038484 PMCID: PMC3824111 DOI: 10.1038/emi.2013.48] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 06/12/2013] [Accepted: 06/18/2013] [Indexed: 12/20/2022]
Abstract
China is undergoing a recent outbreak of a novel H7N9 avian influenza virus (nH7N9) infection that has thus far involved 132 human patients, including 37 deaths. The nH7N9 virus is a reassortant virus originating from the H7N3, H7N9 and H9N2 avian influenza viruses. nH7N9 isolated from humans contains features related to adaptation to humans, including a Q226L mutation in the hemagglutinin cleavage site and E627K and D701N mutations in the PB2 protein. Live poultry markets provide an environment for the emergence, spread and maintenance of nH7N9 as well as for the selection of mutants that facilitate nH7N9 binding to and replication in the human upper respiratory tract. Innate immune suppression conferred by the internal genes of H9N2 may contribute to the virulence of nH7N9. The quail may serve as the intermediate host during the adaptation of avian influenza viruses from domestic waterfowl to gallinaceous poultry, such as chickens and related terrestrial-based species, due to the selection of viral mutants with a short neuraminidase stalk. Infections in chickens, common quails, red-legged partridges and turkeys may select for mutants with human receptor specificity. Infection in Ratitae species may lead to the selection of PB2-E627K and PB2-D701N mutants and the conversion of nH7N9 to a highly pathogenic avian influenza virus.
Collapse
Affiliation(s)
- Kang Yiu Lai
- Department of Intensive Care, Queen Elizabeth Hospital , Hong Kong, China
| | - George Wing Yiu Ng
- Department of Intensive Care, Queen Elizabeth Hospital , Hong Kong, China
| | - Kit Fai Wong
- Department of Pathology, Queen Elizabeth Hospital , Hong Kong, China
| | | | | | - Fanny Fan Cheng
- Department of Medicine, Queen Elizabeth Hospital , Hong Kong, China
| | | |
Collapse
|
25
|
Yu H, Cowling BJ, Feng L, Lau EHY, Liao Q, Tsang TK, Peng Z, Wu P, Liu F, Fang VJ, Zhang H, Li M, Zeng L, Xu Z, Li Z, Luo H, Li Q, Feng Z, Cao B, Yang W, Wu JT, Wang Y, Leung GM. Human infection with avian influenza A H7N9 virus: an assessment of clinical severity. Lancet 2013; 382:138-45. [PMID: 23803487 PMCID: PMC3801178 DOI: 10.1016/s0140-6736(13)61207-6] [Citation(s) in RCA: 209] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Characterisation of the severity profile of human infections with influenza viruses of animal origin is a part of pandemic risk assessment, and an important part of the assessment of disease epidemiology. Our objective was to assess the clinical severity of human infections with avian influenza A H7N9 virus, which emerged in China in early 2013. METHODS We obtained information about laboratory-confirmed cases of avian influenza A H7N9 virus infection reported as of May 28, 2013, from an integrated database built by the Chinese Center for Disease Control and Prevention. We estimated the risk of fatality, mechanical ventilation, and admission to the intensive care unit for patients who required hospital admission for medical reasons. We also used information about laboratory-confirmed cases detected through sentinel influenza-like illness surveillance to estimate the symptomatic case fatality risk. FINDINGS Of 123 patients with laboratory-confirmed avian influenza A H7N9 virus infection who were admitted to hospital, 37 (30%) had died and 69 (56%) had recovered by May 28, 2013. After we accounted for incomplete data for 17 patients who were still in hospital, we estimated the fatality risk for all ages to be 36% (95% CI 26-45) on admission to hospital. Risks of mechanical ventilation or fatality (69%, 95% CI 60-77) and of admission to an intensive care unit, mechanical ventilation, or fatality (83%, 76-90) were high. With assumptions about coverage of the sentinel surveillance network and health-care-seeking behaviour for patients with influenza-like illness associated with influenza A H7N9 virus infection, and pro-rata extrapolation, we estimated that the symptomatic case fatality risk could be between 160 (63-460) and 2800 (1000-9400) per 100,000 symptomatic cases. INTERPRETATION Human infections with avian influenza A H7N9 virus seem to be less serious than has been previously reported. Many mild cases might already have occurred. Continued vigilance and sustained intensive control efforts are needed to minimise the risk of human infection. FUNDING Chinese Ministry of Science and Technology; Research Fund for the Control of Infectious Disease; Hong Kong University Grants Committee; China-US Collaborative Program on Emerging and Re-emerging Infectious Diseases; Harvard Center for Communicable Disease Dynamics; US National Institute of Allergy and Infectious Disease; and the US National Institutes of Health.
Collapse
Affiliation(s)
- Hongjie Yu
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|