[Infectious diseases, the veritable pandora's box]

The past few years, much attention has been given to the problems regarding new and emerging infectious diseases. Four groups may be considered: (1) new agents discovered among the causes of classical medical syndromes, these do not constitute new dangers but decrease the proportion of unknown causes within these syndromes; (2) increased importance of infectious agents resulting from modified ways of living or production procedures; (3) the really new agents, the spread of which is generally favoured by the same factors and (4) organisms with acquired resistance against antibiotics and pesticides. There is need for extended epidemiological surveillance, that can be improved in our country by better collaboration between different organisations. Most importantly epidemiological surveillance should be organized on an European level with the entire support of our regional and federal authorities.