Environmental Factors Contributing to the Spread of H5N1 Avian Influenza in Mainland China

Abstract

BackgroundSince 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 FindingsA 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/SignificanceOur 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.

Epidemiological parameter changes of global Avian Influenza H5N1 over two decades, from 1997 to 2017

“…[8-10], The spread of avian influenza (H5N1) virus over sixteen countries from East Asia to west Asia and North Africa might related to global bird season's migration. [11,12] Therefore, increasing virus spread range and outbreaks among birds might increase the risk of human exposure [13]. Incidence were more in low temperature seasons (autumn and winter), started from November to March.…”

Transmissibility of the highly pathogenic avian influenza virus, subtype H5N1 in domestic poultry: a spatio-temporal estimation at the global scale

“…2006; Kilpatrick, 2006;Fang et al, 2008). It is possible that sR 0 and stR 0 results were different from tR 0 because these metrics focus on different aspects of disease transmissibility, suggesting that their joint application can provide a more comprehensive profile of disease transmissibility from the temporal, spatial and spatio-temporal perspective.…”

Remote sensing of environmental change over China: A review

“…The most significant impact of environmental change is public health. However, except for avian influenza, schistosomiasis and malaria [80][81][82][83] there are few studies involving remote sensing over China [84,85]. Atmospheric pollution cause health damages not only to urban residents but also to rural citizens [86].…”