The spread of disease--some important problems in the latter years of the twentieth century.
D001424:Bacterial Infections / Q000453:epidemiology*; D006801:Humans; D010272:Parasitic Diseases / Q000453:epidemiology*; D013997:Time Factors; D014195:Travel; D006113:United Kingdom; D014777:Virus Diseases / Q000453:epidemiology*