Future UK land use policy and the risk of infectious disease in humans, livestock and wild animals
Arinaminpathy N., McLean AR., Godfray HCJ.
We explore the degree to which the consideration of infectious diseases may be of importance in the formulation of land use policy. We look at the diseases of humans, domestic livestock and wild vertebrates, and distinguish two types of human disease: those which form epidemics involving transmission from person to person, and those which are contracted from non-human sources and spread very little through the population. Land use affects the density and distribution of people, and urbanisation typically increases the risk of an epidemic and the speed with which it spreads. More subtle effects may occur through changes in the network of contacts between individuals. Land use policy that affects the distribution of breeding sites for disease vectors (e.g. mosquitoes) or the passage of potential pathogenic microorganisms through the environment from farm animals to humans can also influence non-epidemic disease risk. Livestock disease is critically affected by stocking density and the network of contacts between individuals and herds. Land use and agricultural policy can be very important in reducing the risks of disease outbreaks. We explore the complex relationship between intensification and disease risks. We suspect that land use policy may affect the viability of threatened species of vertebrates, though our relatively poor knowledge of disease epidemiology in wild animals makes policy formation difficult. Though climate change may act together with land use policy to determine disease risk, we consider this interaction to less important than that between land use and the socioeconomic drivers of global change. We conclude by assessing the importance of disease in the three types of host to land use policy. We suggest that the consideration of wildlife diseases is a low to medium priority for land use policy, though we attach high uncertainty to our conclusion; the consideration of human diseases we think a low priority (with medium uncertainty); while that of livestock diseases we argue is a high priority (with low uncertainty). © 2009 Queen's Printer and Controller of HMSO.