TY - JOUR
T1 - Risk factors for influenza A(H7N9) disease--China, 2013
AU - Liu, Bo
AU - Havers, Fiona
AU - Chen, Enfu
AU - Yuan, Zhengan
AU - Yuan, Hui
AU - Ou, Jianming
AU - Shang, Mei
AU - Kang, Kai
AU - Liao, Kaiju
AU - Liu, Fuqiang
AU - Li, Dan
AU - Ding, Hua
AU - Zhou, Lei
AU - Zhu, Weiping
AU - Ding, Fan
AU - Zhang, Peng
AU - Wang, Xiaoye
AU - Yao, Jianyi
AU - Xiang, Nijuan
AU - Zhou, Suizan
AU - Liu, Xiaoqin
AU - Song, Ying
AU - Su, Hualin
AU - Wang, Rui
AU - Cai, Jian
AU - Cao, Yang
AU - Wang, Xianjun
AU - Bai, Tian
AU - Wang, Jianjun
AU - Feng, Zijian
AU - Zhang, Yanping
AU - Widdowson, Marc-Alain
AU - Li, Qun
N1 - © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: [email protected].
PY - 2014/9/15
Y1 - 2014/9/15
N2 - BACKGROUND: The majority of human cases of novel avian influenza A(H7N9), which emerged in China in spring 2013, include reported 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 8 Chinese provinces. Patients with laboratory-confirmed A(H7N9) (n = 89) were matched by 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 (ORs) for the association of A(H7N9) virus infection with potential risk factors.RESULTS: Fifty-five percent of patients compared with 31% of controls reported any contact with poultry (matched OR [mOR], 7.8; 95% confidence interval [CI], 3.3-18.8). Sixty-seven percent of patients 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.
AB - BACKGROUND: The majority of human cases of novel avian influenza A(H7N9), which emerged in China in spring 2013, include reported 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 8 Chinese provinces. Patients with laboratory-confirmed A(H7N9) (n = 89) were matched by 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 (ORs) for the association of A(H7N9) virus infection with potential risk factors.RESULTS: Fifty-five percent of patients compared with 31% of controls reported any contact with poultry (matched OR [mOR], 7.8; 95% confidence interval [CI], 3.3-18.8). Sixty-seven percent of patients 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.
KW - Adolescent
KW - Adult
KW - Aged
KW - Aged, 80 and over
KW - Case-Control Studies
KW - Child
KW - China/epidemiology
KW - Female
KW - Health Behavior
KW - History, 21st Century
KW - Humans
KW - Influenza A Virus, H7N9 Subtype/genetics
KW - Influenza, Human/epidemiology
KW - Male
KW - Middle Aged
KW - Public Health Surveillance
KW - Risk Factors
KW - Seroepidemiologic Studies
KW - Young Adult
U2 - 10.1093/cid/ciu423
DO - 10.1093/cid/ciu423
M3 - A1: Web of Science-article
C2 - 24928293
SN - 1058-4838
VL - 59
SP - 787
EP - 794
JO - Clinical Infectious Diseases
JF - Clinical Infectious Diseases
IS - 6
ER -