Risk factors for influenza A(H7N9) disease--China, 2013

Bo Liu; Fiona Havers; Enfu Chen; Zhengan Yuan; Hui Yuan; Jianming Ou; Mei Shang; Kai Kang; Kaiju Liao; Fuqiang Liu; Dan Li; Hua Ding; Lei Zhou; Weiping Zhu; Fan Ding; Peng Zhang; Xiaoye Wang; Jianyi Yao; Nijuan Xiang; Suizan Zhou; Xiaoqin Liu; Ying Song; Hualin Su; Rui Wang; Jian Cai; Yang Cao; Xianjun Wang; Tian Bai; Jianjun Wang; Zijian Feng; Yanping Zhang; Marc-Alain Widdowson; Qun Li

doi:10.1093/cid/ciu423

Risk factors for influenza A(H7N9) disease--China, 2013

Bo Liu, Fiona Havers, Enfu Chen, Zhengan Yuan, Hui Yuan, Jianming Ou, Mei Shang, Kai Kang, Kaiju Liao, Fuqiang Liu, Dan Li, Hua Ding, Lei Zhou, Weiping Zhu, Fan Ding, Peng Zhang, Xiaoye Wang, Jianyi Yao, Nijuan Xiang, Suizan ZhouXiaoqin Liu, Ying Song, Hualin Su, Rui Wang, Jian Cai, Yang Cao, Xianjun Wang, Tian Bai, Jianjun Wang, Zijian Feng, Yanping Zhang, Marc-Alain Widdowson, Qun Li

Institute of Tropical Medicine

Research output: Contribution to journal › A1: Web of Science-article › peer-review

Abstract

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.

Original language	English
Journal	Clinical Infectious Diseases
Volume	59
Issue number	6
Pages (from-to)	787-794
Number of pages	8
ISSN	1058-4838
DOIs	https://doi.org/10.1093/cid/ciu423
Publication status	Published - 15-Sept-2014

Keywords

Adolescent
Adult
Aged
Aged, 80 and over
Case-Control Studies
Child
China/epidemiology
Female
Health Behavior
History, 21st Century
Humans
Influenza A Virus, H7N9 Subtype/genetics
Influenza, Human/epidemiology
Male
Middle Aged
Public Health Surveillance
Risk Factors
Seroepidemiologic Studies
Young Adult

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10.1093/cid/ciu423

Cite this

@article{ff013698b4ef4ac89883f9f5d59b1696,

title = "Risk factors for influenza A(H7N9) disease--China, 2013",

abstract = "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.",

keywords = "Adolescent, Adult, Aged, Aged, 80 and over, Case-Control Studies, Child, China/epidemiology, Female, Health Behavior, History, 21st Century, Humans, Influenza A Virus, H7N9 Subtype/genetics, Influenza, Human/epidemiology, Male, Middle Aged, Public Health Surveillance, Risk Factors, Seroepidemiologic Studies, Young Adult",

author = "Bo Liu and Fiona Havers and Enfu Chen and Zhengan Yuan and Hui Yuan and Jianming Ou and Mei Shang and Kai Kang and Kaiju Liao and Fuqiang Liu and Dan Li and Hua Ding and Lei Zhou and Weiping Zhu and Fan Ding and Peng Zhang and Xiaoye Wang and Jianyi Yao and Nijuan Xiang and Suizan Zhou and Xiaoqin Liu and Ying Song and Hualin Su and Rui Wang and Jian Cai and Yang Cao and Xianjun Wang and Tian Bai and Jianjun Wang and Zijian Feng and Yanping Zhang and Marc-Alain Widdowson and Qun Li",

note = "{\textcopyright} 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].",

year = "2014",

month = sep,

day = "15",

doi = "10.1093/cid/ciu423",

language = "English",

volume = "59",

pages = "787--794",

journal = "Clinical Infectious Diseases",

issn = "1058-4838",

publisher = "Oxford University Press",

number = "6",

}

Liu, B, Havers, F, Chen, E, Yuan, Z, Yuan, H, Ou, J, Shang, M, Kang, K, Liao, K, Liu, F, Li, D, Ding, H, Zhou, L, Zhu, W, Ding, F, Zhang, P, Wang, X, Yao, J, Xiang, N, Zhou, S, Liu, X, Song, Y, Su, H, Wang, R, Cai, J, Cao, Y, Wang, X, Bai, T, Wang, J, Feng, Z, Zhang, Y, Widdowson, M-A & Li, Q 2014, 'Risk factors for influenza A(H7N9) disease--China, 2013', Clinical Infectious Diseases, vol. 59, no. 6, pp. 787-794. https://doi.org/10.1093/cid/ciu423

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

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 -

Risk factors for influenza A(H7N9) disease--China, 2013

Abstract

Keywords

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