Epidemiology of the avian influenza A (H7N9) outbreak in Zhejiang Province, China

BMC Infectious Diseases

Enfu Chen³  Zhao Yu³  Jian Cai³  Chengliang Chai³  Jimin Sun³  Jiankang Han¹  Hua Ding²  Huakun Lv³  Zhenyu Gong³ 

[1] Huzhou Municipal Center for Disease Control and Prevention, Huzhou, China;Hangzhou Municipal Center for Disease Control and Prevention, Hangzhou, China;Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China

关键词: Multi-exposure;    Rural cases;    Epidemiology;    Avian influenza A (H7N9) virus;   

Others  :  1131254
DOI  :  10.1186/1471-2334-14-244

 received in 2013-10-23, accepted in 2014-04-30,  发布年份 2014

【 摘 要 】

Background

A novel influenza A virus infection was identified on March 31, 2013 in China and a total of 134 cases were identified in 12 provinces of China between March 25 and September 31, 2013. Of these, 46 cases occurred in Zhejiang Province and the number of patients is the largest in China.

Methods

Field investigations were conducted for each confirmed H7N9 case. A standardized questionnaire was used to collect information about demographics, exposure history, clinical signs and symptoms, timelines of medical visits and care after onset of illness, and close contacts. Descriptive statistics were used to analyze the epidemiological and clinical characteristics. Samples from the patients were collected and tested by real time reverse transcriptase-polymerase chain reaction and viral culture.

Results

A total of 46 laboratory confirmed cases of H7N9 influenza infection were identified in the Zhejiang province between March 31 and September 31, 2013 of which 29 were male and 17 were female. The median age of patients was 61.5 years and 76.09% of cases occurred in persons aged ≥50 years old. Unlike other province, 34.78% of cases in Zhejiang Province were rural residents. Among 11 deaths, 9 were male, 10 were older than 60 years old, and 10 had underlying diseases. 30 of 38 cases with available data had a recent history of poultry exposures and 8 cases had multi-exposure history. The estimated median incubation period was two days which was shorter than corresponding data in other provinces. All cases were hospitalized and the median time from illness onset to hospitalization was 5 days. Symptoms at the onset of the illness included fever, cough, expectoration, shivering, fatigue, muscular aches, nausea, vomiting. Only 4.91% contacts developed respiratory symptoms, but their samples were tested negative for H7N9 virus designating lack of human-to-human transmission of the virus.

Conclusions

All cases were sporadic and there was no evidence of an epidemiologic link between them. Control measures including closing affected poultry and slaughtering backyard poultry are needed not only in urban areas but also in rural areas to reduce human H7N9 infection risk.

【 授权许可】

   
2014 Gong et al.; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Fouchier RA, Munster V, Wallensten A, Bestebroer TM, Herfst S, Smith D, Rimmelzwaan GF, Olsen B, Osterhaus AD: Characterization of a novel influenza A virus hemagglutinin subtype (H16) obtained from black headed gulls. J Virol 2005, 79:2814-2822.
• [2]Hirst M, Astell CR, Griffith M, Coughlin SM, Moksa M, Zeng T: Novel avian influenza H7N3 strain outbreak, British Columbia. Viruses 2009, 1:1351-1363.
• [3]Hirst M, Astell CR, Griffith M, Coughlin SM, Moksa M, Zeng T, Smailus DE, Holt RA, Jones S, Marra MA, Petric M, Krajden M, Lawrence D, Mak A, Chow R, Skowronski DM, Tweed SA, Goh S, Brunham RC, Robinson J, Bowes V, Sojonky K, Byrne SK, Li Y, Kobasa D, Booth T, Paetzel M: Novel avian influenza H7N3 strain outbreak, British Columbia. Emerg Infect Dis 2004, 10:2192-2195.
• [4]Nguyen VanTam JS, Nair P, Acheson P, Baker A, Barker M, Bracebridge S, Croft J, Ellis J, Gelletlie R, Gent N, Ibbotson S, Joseph C, Mahgoub H, Monk P, Reghitt TW, Sundkvist T, Sellwood C, Simpson J, Smith J, Watson JM, Zambon M, Lightfoot N, Incident Response Team: Outbreak of low pathogenicity H7N3 avian influenza in UK, including associated case of human conjunctivitis. Euro Surveill 2006, 11:E060504-E060507.
• [5]Arzey GG, Kirkland PD, Arzey KE, Frost M, Maywood P, Conaty S, Hurt AC, Deng YM, Iannello P, Barr I, Dwyer DE, Ratnamohan M, McPhie K, Selleck P: Influenza virus A (H10N7) in chickens and poultry abattoir workers, Australia. Emerg Infect Dis 2012, 18:814-816.
• [6]Fouchier RA, Schneeberger PM, Rozendaal FW, Broekman JM, Kemink SG, Munster V, Kuiken T, Rimmelzwaan GF, Schutten M, Van Doornum GJ, Koch G, Bosman A, Koopmans M, Osterhaus AD: Avian influenza A virus (H7N7) associated with human conjunctivitis and a fatal case of acute respiratory distress syndrome. Proc Natl Acad Sci U S A 2004, 101:1356-1361.
• [7]Koopmans M, Wilbrink B, Conyn M, Natrop G, Nat HVD, Vennema H, Meijer A, van Steenbergen J, Fouchier R, Osterhaus A, Bosman A: Transmission of H7N7 avian influenza A virus to human beings during a large outbreak in commercial poultry farms in the Netherlands. Lancet 2004, 363:587-593.
• [8]WHO Disease Outbreak News H7N9 avian influenza human infections in China WHO April 1st 2013 http://www.who.int/csr/don/2013_04_01/en/index.html webcite
• [9]Gao RB, Cao B, Hu Y, Feng Z, Wang D, Hu W, Chen J, Jie Z, Qiu H, Xu K, Xu X, Lu H, Zhu W, Gao Z, Xiang N, Shen Y, He Z, Gu Y, Zhang Z, Yang Y, Zhao X, Zhou L, Li X, Zou S, Zhang Y, Li X, Yang L, Guo J, Dong J, Li Q, et al.: Human infection with a novel avian-origin influenza A (H7N9) virus. N Engl J Med 2013, 368:1888-1897.
• [10]Kageyama T, Fujisaki S, Takashita E, Xu H, Yamada S, Uchida Y, Neumann G, Saito T, Kawaoka Y, Tashiro M: Genetic analysis of novel avian A(H7N9) influenza viruses isolated from patients in China, February to April 2013. Euro Surveill 2013, 18:20453.
• [11]The diagnosis and treatment programs of human infections with H7N9 virus http://www.moh.gov.cn/mohyzs/s3586/201304/826ca1fb686f41ab9e8938ecdfa46a70.shtml webcite
• [12]The prevention and control programs of human infections with H7N9 virus http://www.moh.gov.cn/mohjbyfkzj/s3578/201304/c1ab8ea6b2bf447dbfda724cc0afbb6e.shtml webcite
• [13]WHO: Cumulative number of confirmed human cases for avian influenza A (H5N1) reported to WHO, 2003–2013.
• [14]WHO: Epidemiology of WHO-confirmed human cases of avian influenza A (H5N1) infection. Wkly Epidemiol Rec 2006, 81:249-260.
• [15]Qun L, Lei Z, Minghao Z, Zhiping C, Furong L, Huanyu W, Nijuan X, Enfu C, Fenyang T, Dayan W, Ling M, Zhiheng H, Wenxiao T, Yang C, Leilei L, Fan D, Bo L, Mei W, Rongheng X, Rongbao G, Xiaodan L, Tian B, Shumei Z, Jun H, Jiayu H, Yangting X, Chengliang C, Shiwen W, Yongjun G, Lianmei J, et al.: Preliminary report: epidemiology of the Avian Influenza A (H7N9) Outbreak in China. N Engl J Med 2013. doi:10.1056/NEJMoa1304617
• [16]Yuen KY, Chan PK, Peiris M, Tang DNC, Que TL, Shortridge KF, Cheung PT, To WK, Ho ET, Sung R, Cheng AF: Clinical features and rapid viral diagnosis of human disease associated with avian influenza A H5N1 virus. Lancet 1998, 351:467-471.
• [17]Nicholson KG, Wood JM, Zambon M: Influenza. Lancet 2003, 362:1733-1745.
• [18]Peiris JS, de Jong MD, Guan Y: Avian influenza virus (H5N1): a threat to human health. Clin Microbiol Rev 2007, 20:243-267.
• [19]Bai L, Gu L, Cao B, Zhai XL, Lu M, Lu Y, Liang LR, Zhang L, Gao ZF, Huang KW, Liu YM, Song SF, Wu L, Yin YD, Wang C: Clinical features of pneumonia caused by influenza A (H1N1) virus in Beijing, China. Chest 2011, 139:1156-1164.
• [20]Liem NT, Tung CV, Hien ND, Hien TT, Chau NQ, Long HT, Hien NT, Mai le Q, Taylor WR, Wertheim H, Farrar J, Khang DD, Horby P: Clinical features of human influenza A (H5N1) infection in Vietnam: 2004–2006. Clin Infect Dis 2009, 48:1639-1646.
• [21]Mounts AW, Kwong H, Izurieta HS, Ho YY, Au TK, Lee M, Buxton Bridges C, Williams SW, Mak KH, Katz JM, Thompson WW, Cox NJ, Fukuda K: Case–control study of risk factors for avian influenza A (H5N1) disease, Hong Kong, 1997. J Infect Dis 1999, 180:505-508.
• [22]Yu H, Feng Z, Zhang X, Xiang N, Huai Y, Zhou L, Li Z, Xu C, Luo H, He J, Guan X, Yuan Z, Li Y, Xu L, Hong R, Liu X, Zhou X, Yin W, Zhang S, Shu Y, Wang M, Wang Y, Lee CK, Uyeki TM, Yang W: Human influenza A(H5N1) cases, urban areas of People’s Republic of China, 2005–2006. Emerg Infect Dis 2007, 13:1061-1064.
• [23]Zhou L, Liao QH, Dong LB, Huai Y, Bai T, Xiang N, Shu Y, Liu W, Wang S, Qin P, Wang M, Xing X, Lv J, Chen RY, Feng Z, Yang W, Uyeki TM, Yu H: Risk factors for human illness with avian influenza A (H5N1) virus infection in China. J Infect Dis 2009, 199:1726-1734.
• [24]Chen Y, Liang W, Yang S, Wu N, Gao H, Sheng J, Yao H, Wo J, Fang Q, Cui D, Li Y, Yao X, Zhang Y, Wu H, Zheng S, Diao H, Xia S, Zhang Y, Chan KH, Tsoi HW, Teng JL, Song W, Wang P, Lau SY, Zheng M, Chan JF, To KK, Chen H, Li L, Yuen KY: Human infections with the emerging avian influenza A H7N9 virus from wet market poultry: clinical analysis and characterisation of viral genome. Lancet 2013, (13):60903-4. doi:10.1016/S0140-6736
• [25]Yang S, Chen Y, Cui D, Yao H, Lou J, Huo Z, Xie G, Yu F, Zheng S, Yang Y, Zhu Y, Lu X, Liu X, Lau SY, Chan JF, To KK, Yuen KY, Chen H, Li L: Avian-origin H7N9 virus infection in H7N9-affected areas of China: a serological study. J Infect Dis 2013, 209:265-269.
• [26]Wang H, Feng Z, Shu Y, Yu H, Zhou L, Zu R, Huai Y, Dong J, Bao C, Wen L, Wang H, Yang P, Zhao W, Dong L, Zhou M, Liao Q, Yang H, Wang M, Lu X, Shi Z, Wang W, Gu L, Zhu F, Li Q, Yin W, Yang W, Li D, Uyeki TM, Wang Y: Probable limited person-to-person transmission of highly pathogenic avian influenza A (H5N1) virus in China. Lancet 2008, 371:1427-1434.
• [27]Kandun IN, Wibisono H, Sedyaningsih ER, Yusharmen , Hadisoedarsuno W, Purba W, Purba W, Santoso H, Septiawati C, Tresnaningsih E, Heriyanto B, Yuwono D, Harun S, Soeroso S, Giriputra S, Blair PJ, Jeremijenko A, Kosasih H, Putnam SD, Samaan G, Silitonga M, Chan KH, Poon LL, Lim W, Klimov A, Lindstrom S, Guan Y, Donis R, Katz J, Cox N, et al.: Three Indonesian clusters of H5N1 virus infection in 2005. N Engl J Med 2006, 355:2186-2194.
• [28]Ungchusak K, Auewarakul P, Dowell SF, Kitphati R, Auwanit W, Puthavathana P, Uiprasertkul M, Boonnak K, Pittayawonganon C, Cox NJ, Zaki SR, Thawatsupha P, Chittaganpitch M, Khontong R, Simmerman JM, Chunsutthiwat S: Probable person-to-person transmission of avian influenza A (H5N1). N Engl J Med 2005, 352:333-340.
• [29]Qi X, Qian YH, Bao CJ, Guo XL, Cui LB, Tang FY, Ji H, Huang Y, Cai PQ, Lu B, Xu K, Shi C, Zhu FC, Zhou MH, Wang H: Probable person to person transmission of novel avian influenza A (H7N9) virus in Eastern China, 2013: epidemiological investigation. BMJ 2013, 347:f4752. doi:10.1136
• [30]Yu H, Gao Z, Feng Z, Shu Y, Xiang N, Zhou L, Huai Y, Feng L, Peng Z, Li Z, Xu C, Li J, Hu C, Li Q, Xu X, Liu X, Liu Z, Xu L, Chen Y, Luo H, Wei L, Zhang X, Xin J, Guo J, Wang Q, Yuan Z, Zhou L, Zhang K, Zhang W, Yang J, et al.: Clinical characteristics of 26 human cases of highly pathogenic avian influenza A (H5N1) virus infection in China. PLoS One 2008, 3:e2985.
• [31]Lu S, Xi X, Zheng Y, Cao Y, Liu XN, Lu HZ: Analysis of the clinical characteristics and treatment of two patients with avian influenza virus (H7N9). Biosci Trends 2013, 7:109-112.
• [32]Gao HN, Lu HZ, Cao B, Du B, Shang H, Gan JH, Lu SH, Yang YD, Fang Q, Shen YZ, Xi XM, Gu Q, Zhou XM, Qu HP, Yan Z, Li FM, Zhao W, Gao ZC, Wang GF, Ruan LX, Wang WH, Ye J, Cao HF, Li XW, Zhang WH, Fang XC, He J, Liang WF, Xie J, Zeng M, et al.: Clinical findings in 111 cases of Influenza A (H7N9) virus infection. N Engl J Med 2013, 368:2277-2285.
• [33]Liu S, Sun J, Cai J, Miao Z, Lu M, Qin S, Wang X, Lv H, Yu Z, Amer S, Chai C: Epidemiological, clinical and viral characteristics of fatal cases of human avian influenza A (H7N9) virus in Zhejiang Province, China. J Infect 2013. doi:10.1016