[Fever of unknown origin : infectious etiology and diagnosis principles]

The paper has 3 parts: definitions, causes and diagnosis principles in prolonged fevers of infections etiology. The non infections causes of FUO are only mentioned. The infections causes are presented as: Bacteria, Viruses, Mycetes and Protozoa. The part regarding the etiological diagnosis firstly includes data about the microbiological diagnosis methods and samples in four steps: a) routine samples done for every febrile patient in a general hospital; b) all the accessible samples and c) samples obtained by invasive procedures (needle biopsies and open biopsies). When all of these had negative results in microbiological tests, a last possibility is adopted: exploratory laparatomy, eventually by sampling some specimens. Finally, conditions of obtaining interpretable serological tests are listed.