sharon sanders
Editor-in-Chief & President
Risk Factors for Influenza A(H7N9) Disease ? China, 2013
Risk Factors for Influenza A(H7N9) Disease ? China, 2013
Bo Liu1,*, Fiona Havers2,*, Enfu Chen3,*, Zhengan Yuan4,*, Hui Yuan12, Jianming Ou5, Mei Shang6, Kai Kang7, Kaiju Liao1, Fuqiang Liu8, Dan Li1, Hua Ding9, Lei Zhou1, Weiping Zhu10, Fan Ding1, Peng Zhang11, Xiaoye Wang1, Jianyi Yao1, Nijuan Xiang1, Suizan Zhou6, Xiaoqin Liu12, Ying Song6, Hualin Su13, Rui Wang1, Jian Cai3, Yang Cao1, Xianjun Wang14, Tian Bai15, Jianjun Wang16, Zijian Feng1, Yanping Zhang1, Marc-Alain Widdowson17, and Qun Li1
+ Author Affiliations
1Public Health Emergency Center, Chinese Center for Disease Control and Prevention, Beijing, China
2Epidemic Intelligence Service assigned to the Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA
3Influenza Division, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
4Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China
5Fujian Provincial Center for Disease Control and Prevention, Fuzhou, Fujian Province, China
6China Office, US Centers for Disease Control and Prevention, Beijing, China
7Henan Provincial Center for Disease Control and Prevention, Zhengzhou, Henan Province, China
8Hunan Provincial Center for Disease Control and Prevention, Changsha, Hunan Province, China
9Zhejiang Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
10Shanghai Pudong New Area Center for Disease Control and Prevention, Shanghai, China
11Zhejiang Huzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
12Jiangxi Provincial Center for Disease Control and Prevention, Nanchang, Jiangxi Province, China
13Shanghai Minhang District Center for Disease Control and Prevention, Shanghai, China
14Shandong Provincial Center for Disease Control and Prevention, Jinan City, Shandong Province, China
15Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
16Anhui Provincial Center for Disease Control and Prevention, Hefei, Henan Province, China
17Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA
Corresponding author: Dr. Qun Li, Public Health Emergency Center, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Beijing 102206, P. R. China. liqun@chinacdc.cn, +86-10-58900545
↵* These authors contributed equally to this manuscript.
Alternate corresponding author: Bo Liu, Public Health Emergency Center, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, P.R. China, 102206, Tel /Fax: 86-10-58900506, Email: liubo@chinacdc.cn
Abstract
Background. The majority of humans cases of novel avian influenza A(H7N9), which emerged in China in spring 2013, report exposure to poultry. However, specific host and exposure risk factors for disease are unknown, yet critical to design prevention measures.
Methods. In April?June 2013, we conducted a case-control study in eight Chinese provinces. Laboratory-confirmed A(H7N9) cases (n=89) were matched on age, sex, and neighborhood to controls (n=339). Subjects completed a questionnaire on medical history and potential exposures, including poultry markets and other poultry exposure. We used conditional logistic regression to calculate matched and adjusted odds ratios for the association of A(H7N9) virus infection with potential risk factors.
Results. Fifty-five percent of cases compared with 31% of controls reported any contact with poultry (matched OR [mOR]: 7.8; 95% confidence interval [CI]: 3.3?18.8). 67% of cases compared with 35% of controls visited a live poultry market (mOR: 5.4; CI: 3.0?9.7). Visiting live poultry markets increased risk of infection even after adjusting for poultry contact and other confounders (adjusted OR: 3.4; CI: 1.8?6.7). Backyard poultry were not associated with increased risk; 14% of cases did not report any poultry exposure or market visit. Obesity (mOR: 4.7; CI: 1.8?12.4), chronic obstructive pulmonary disease (mOR: 2.7; CI: 1.1?6.9), and immunosuppressive medications (mOR: 9.0; CI: 1.7?47.2) were associated with A(H7N9) disease.
Conclusion. Exposures to poultry in markets were associated with A(H7N9) virus infection, even without poultry contact. China should consider permanently closing live poultry markets or aggressively pursuing control measures to prevent spread of this emerging pathogen.
Received February 19, 2014.
Accepted May 2, 2014.
http://cid.oxfordjournals.org/content/early/2014/06/13/cid.ciu423.abstract
Risk Factors for Influenza A(H7N9) Disease ? China, 2013
Bo Liu1,*, Fiona Havers2,*, Enfu Chen3,*, Zhengan Yuan4,*, Hui Yuan12, Jianming Ou5, Mei Shang6, Kai Kang7, Kaiju Liao1, Fuqiang Liu8, Dan Li1, Hua Ding9, Lei Zhou1, Weiping Zhu10, Fan Ding1, Peng Zhang11, Xiaoye Wang1, Jianyi Yao1, Nijuan Xiang1, Suizan Zhou6, Xiaoqin Liu12, Ying Song6, Hualin Su13, Rui Wang1, Jian Cai3, Yang Cao1, Xianjun Wang14, Tian Bai15, Jianjun Wang16, Zijian Feng1, Yanping Zhang1, Marc-Alain Widdowson17, and Qun Li1
+ Author Affiliations
1Public Health Emergency Center, Chinese Center for Disease Control and Prevention, Beijing, China
2Epidemic Intelligence Service assigned to the Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA, USA
3Influenza Division, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
4Shanghai Municipal Center for Disease Control and Prevention, Shanghai, China
5Fujian Provincial Center for Disease Control and Prevention, Fuzhou, Fujian Province, China
6China Office, US Centers for Disease Control and Prevention, Beijing, China
7Henan Provincial Center for Disease Control and Prevention, Zhengzhou, Henan Province, China
8Hunan Provincial Center for Disease Control and Prevention, Changsha, Hunan Province, China
9Zhejiang Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
10Shanghai Pudong New Area Center for Disease Control and Prevention, Shanghai, China
11Zhejiang Huzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang Province, China
12Jiangxi Provincial Center for Disease Control and Prevention, Nanchang, Jiangxi Province, China
13Shanghai Minhang District Center for Disease Control and Prevention, Shanghai, China
14Shandong Provincial Center for Disease Control and Prevention, Jinan City, Shandong Province, China
15Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
16Anhui Provincial Center for Disease Control and Prevention, Hefei, Henan Province, China
17Influenza Division, US Centers for Disease Control and Prevention, Atlanta, GA
Corresponding author: Dr. Qun Li, Public Health Emergency Center, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Beijing 102206, P. R. China. liqun@chinacdc.cn, +86-10-58900545
↵* These authors contributed equally to this manuscript.
Alternate corresponding author: Bo Liu, Public Health Emergency Center, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing, P.R. China, 102206, Tel /Fax: 86-10-58900506, Email: liubo@chinacdc.cn
Abstract
Background. The majority of humans cases of novel avian influenza A(H7N9), which emerged in China in spring 2013, report exposure to poultry. However, specific host and exposure risk factors for disease are unknown, yet critical to design prevention measures.
Methods. In April?June 2013, we conducted a case-control study in eight Chinese provinces. Laboratory-confirmed A(H7N9) cases (n=89) were matched on age, sex, and neighborhood to controls (n=339). Subjects completed a questionnaire on medical history and potential exposures, including poultry markets and other poultry exposure. We used conditional logistic regression to calculate matched and adjusted odds ratios for the association of A(H7N9) virus infection with potential risk factors.
Results. Fifty-five percent of cases compared with 31% of controls reported any contact with poultry (matched OR [mOR]: 7.8; 95% confidence interval [CI]: 3.3?18.8). 67% of cases compared with 35% of controls visited a live poultry market (mOR: 5.4; CI: 3.0?9.7). Visiting live poultry markets increased risk of infection even after adjusting for poultry contact and other confounders (adjusted OR: 3.4; CI: 1.8?6.7). Backyard poultry were not associated with increased risk; 14% of cases did not report any poultry exposure or market visit. Obesity (mOR: 4.7; CI: 1.8?12.4), chronic obstructive pulmonary disease (mOR: 2.7; CI: 1.1?6.9), and immunosuppressive medications (mOR: 9.0; CI: 1.7?47.2) were associated with A(H7N9) disease.
Conclusion. Exposures to poultry in markets were associated with A(H7N9) virus infection, even without poultry contact. China should consider permanently closing live poultry markets or aggressively pursuing control measures to prevent spread of this emerging pathogen.
Received February 19, 2014.
Accepted May 2, 2014.
http://cid.oxfordjournals.org/content/early/2014/06/13/cid.ciu423.abstract