Rickettsial disease: classical and modern aspects.

Rickettsial diseases have been reassessed in recent years since they represent an important field in today's medicine. New agents have been described: some are non-pathogenic agents and the others are associated with well-defined or peculiar clinical patterns. In addition, different species of rickettsiosis are found in relation to the geographic areas of the world. Some agents may be defined as variants of older diseases whereas most of the newly described forms of rickettsiosis represent distinct entities with unique epidemiologial and clinical features. Probably the main news regards the group of the spotted fevers. An additional new aspect is linked to the medicine of travellers and tourists. However, this aspect may not be significant for the rickettsial diseases in relation to other human illnesses, such as malaria. Therefore, an investigation into the geographical origin of patients has to enter our routine medical work.