title: [New and re-emergent epidemics in the changing surrounding world].
abstract: In discussion of the emergence of 'new' diseases or the re-emergence of old ones, much attention has been focused on the appearance of hitherto unknown agents versus the transfer of known agents to new populations. The appearance of a new pathogenic microorganism is often assumed to be the result of a change in its genetic properties. Although this may occasionally be the case, in fact most emergent pathogens have already existed in nature. Some occurring in isolated human populations, others well-established in animal species for centuries. Microbial traffic between animals and man is of special interest. Such cross-species transfer of infectious agents is often the result of changes in human behaviour, or in such human activities as deforestation, dam-building and migration.
authors.affiliation: Infektionskliniken, Sahlgrenska Universitetssjukhuset/Ostra, Göteborg. sten.iwarson@infect.gu.se
authors.forename: S
authors.initials: S
authors.lastname: Iwarson
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission; D003140:Communicable Disease Control; D003428:Cross Infection / Q000382:microbiology; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious; D004199:Disease Vectors; D004781:Environmental Exposure; D006801:Humans; D008019:Life Style; D014195:Travel; D014330:Tropical Medicine; D014777:Virus Diseases / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission