An epidemic of the viral disease nephropathia epidemica (NE) has been linked to increases in the vole population caused by hotter summers, milder winters and increased seedcrop production by broadleaf trees.
Research published in BioMed Central's open access International Journal of Health Geographics links outbreaks of this rodent-borne disease to known effects of global warming.
Dr Jan Clement from the Department of Microbiology & Immunology at Belgium's Rega Institute (University of Leuven) worked with a team of medical researchers and bioscience-engineers to investigate outbreaks of NE in Belgium. Dr. Clement founded the Belgian Hantavirus Reference Centre in 1985, and noted that of the 2,200 cases since then, 828 (37.6%) occurred in just the last three years, 2005-2007. The epidemic has been shown to extend to neighboring countries such as France, Germany, The Netherlands, and Luxembourg. He said, "This animal-borne disease, scarcely known before 1990, has been increasing in incidence in Belgium with a cyclic pattern, reaching epidemic proportions since 2005. The fact that the growing combined effect of hotter summer and autumn seasons is matched by the growth of NE in recent years means this epidemic can be considered an effect of global warming".