Sally Furniss
Well-known member
Environmental Factors Contributing to the Spread of H5N1 Avian Influenza in Mainland China
Li-Qun Fang<sup>1</sup><sup>,</sup><sup>2</sup><sup>#</sup>, Sake J. de Vlas<sup>2</sup><sup>#</sup>, Song Liang<sup>3</sup><sup>#</sup>, Caspar W. N. Looman<sup>2</sup>, Peng Gong<sup>4</sup><sup>,</sup><sup>5</sup>, Bing Xu<sup>6</sup>, Lei Yan<sup>1</sup>, Hong Yang<sup>1</sup>, Jan Hendrik Richardus<sup>2</sup>, Wu-Chun Cao<sup>1</sup><sup>*</sup>
1 Beijing Institute of Microbiology and Epidemiology, State Key Laboratory of Pathogen and Biosecurity, Beijing, People's Republic of China2 Department of Public Health, Erasmus Medical Center (MC), University Medical Center Rotterdam, Rotterdam, The Netherlands3 College of Public Health, The Ohio State University, Columbus, Ohio, United States of America4 State Key Laboratory of Remote Sensing Science, Chinese Academy of Sciences, Beijing Normal University, Beijing, People's Republic of China5 Department of Environmental Science, Policy and Management, University of California, Berkeley, United States of America6 Department of Geography, University of Utah, Salt Lake City, Utah, United States of America
Abstract
Background
Since late 2003, highly pathogenic avian influenza (HPAI) outbreaks caused by infection with H5N1 virus has led to the deaths of millions of poultry and more than 10 thousands of wild birds, and as of 18-March 2008, at least 373 laboratory-confirmed human infections with 236 fatalities, have occurred. The unrestrained worldwide spread of this disease has caused great anxiety about the potential of another global pandemic. However, the effect of environmental factors influencing the spread of HPAI H5N1 virus is unclear.
Methodology/Principal Findings
A database including incident dates and locations was developed for 128 confirmed HPAI H5N1 outbreaks in poultry and wild birds, as well as 21 human cases in mainland China during 2004?2006. These data, together with information on wild bird migration, poultry densities, and environmental variables (water bodies, wetlands, transportation routes, main cities, precipitation and elevation), were integrated into a Geographical Information System (GIS). A case-control design was used to identify the environmental factors associated with the incidence of the disease. Multivariate logistic regression analysis indicated that minimal distance to the nearest national highway, annual precipitation and the interaction between minimal distance to the nearest lake and wetland, were important predictive environmental variables for the risk of HPAI. A risk map was constructed based on these factors.
Conclusions/Significance
Our study indicates that environmental factors contribute to the spread of the disease. The risk map can be used to target countermeasures to stop further spread of the HPAI H5N1 at its source.
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002268
Li-Qun Fang<sup>1</sup><sup>,</sup><sup>2</sup><sup>#</sup>, Sake J. de Vlas<sup>2</sup><sup>#</sup>, Song Liang<sup>3</sup><sup>#</sup>, Caspar W. N. Looman<sup>2</sup>, Peng Gong<sup>4</sup><sup>,</sup><sup>5</sup>, Bing Xu<sup>6</sup>, Lei Yan<sup>1</sup>, Hong Yang<sup>1</sup>, Jan Hendrik Richardus<sup>2</sup>, Wu-Chun Cao<sup>1</sup><sup>*</sup>
1 Beijing Institute of Microbiology and Epidemiology, State Key Laboratory of Pathogen and Biosecurity, Beijing, People's Republic of China2 Department of Public Health, Erasmus Medical Center (MC), University Medical Center Rotterdam, Rotterdam, The Netherlands3 College of Public Health, The Ohio State University, Columbus, Ohio, United States of America4 State Key Laboratory of Remote Sensing Science, Chinese Academy of Sciences, Beijing Normal University, Beijing, People's Republic of China5 Department of Environmental Science, Policy and Management, University of California, Berkeley, United States of America6 Department of Geography, University of Utah, Salt Lake City, Utah, United States of America
Abstract
Background
Since late 2003, highly pathogenic avian influenza (HPAI) outbreaks caused by infection with H5N1 virus has led to the deaths of millions of poultry and more than 10 thousands of wild birds, and as of 18-March 2008, at least 373 laboratory-confirmed human infections with 236 fatalities, have occurred. The unrestrained worldwide spread of this disease has caused great anxiety about the potential of another global pandemic. However, the effect of environmental factors influencing the spread of HPAI H5N1 virus is unclear.
Methodology/Principal Findings
A database including incident dates and locations was developed for 128 confirmed HPAI H5N1 outbreaks in poultry and wild birds, as well as 21 human cases in mainland China during 2004?2006. These data, together with information on wild bird migration, poultry densities, and environmental variables (water bodies, wetlands, transportation routes, main cities, precipitation and elevation), were integrated into a Geographical Information System (GIS). A case-control design was used to identify the environmental factors associated with the incidence of the disease. Multivariate logistic regression analysis indicated that minimal distance to the nearest national highway, annual precipitation and the interaction between minimal distance to the nearest lake and wetland, were important predictive environmental variables for the risk of HPAI. A risk map was constructed based on these factors.
Conclusions/Significance
Our study indicates that environmental factors contribute to the spread of the disease. The risk map can be used to target countermeasures to stop further spread of the HPAI H5N1 at its source.
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002268