The spread of human immunodeficiency virus type 2 into Europe: a geographical analysis.

Geographically-related computer databases on the global incidence of HIV-1 and HIV-2 infection are being maintained in the Department of Geography at the University of Cambridge, England. Using the information they contain, the original geographical heartlands of HIV-2 infection are identified as former Portuguese and French colonies in West and South Central Africa. The same databases permit the reconstruction of the diffusion corridors by which the virus is spreading from these heartlands into Europe. The reconstruction shows that, as a result of traditional links with their former colonies, the main areas of infection in Europe are Portugal and France. These countries have subsequently acted as diffusion nodes for the spread of the virus to other parts of Europe. The patterns of spread thus differ fundamentally from those by which HIV-1 infection arrived in and is moving through Europe.