tetano
Editor, Senior Moderator
Clin Infect Dis. 2014 Jun 13. pii: ciu423. [Epub ahead of print]
Risk Factors for Influenza A(H7N9) Disease - China, 2013.
Liu B1, Havers F2, Chen E3, Yuan Z4, Yuan H5, Ou J6, Shang M7, Kang K8, Liao K1, Liu F9, Li D1, Ding H10, Zhou L1, Zhu W11, Ding F1, Zhang P12, Wang X1, Yao J1, Xiang N1, Zhou S7, Liu X5, Song Y7, Su H13, Wang R1, Cai J3, Cao Y1, Wang X14, Bai T15, Wang J16, Feng Z1, Zhang Y1, Widdowson MA17, Li Q1.
Author information
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.
? 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: journals.permissions@oup.com.
PMID:
24928293
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24928293
Risk Factors for Influenza A(H7N9) Disease - China, 2013.
Liu B1, Havers F2, Chen E3, Yuan Z4, Yuan H5, Ou J6, Shang M7, Kang K8, Liao K1, Liu F9, Li D1, Ding H10, Zhou L1, Zhu W11, Ding F1, Zhang P12, Wang X1, Yao J1, Xiang N1, Zhou S7, Liu X5, Song Y7, Su H13, Wang R1, Cai J3, Cao Y1, Wang X14, Bai T15, Wang J16, Feng Z1, Zhang Y1, Widdowson MA17, Li Q1.
Author information
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.
? 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: journals.permissions@oup.com.
PMID:
24928293
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/24928293