[Urinary infection and its development. Current diagnostic biological data].

The main object of the present article was to show that, independently of the clinical symptoms, the results of three laboratory examinations permit one to make the diagnosis of urinary infection and its degree of severity. 1) Bacteriuria equal or greater than 10(3) bacteria per ml is already significant of an urinary infection and infection of tissues of the urinary tree. If leukocyturia accompanies this bacteriuria, this does not necessarily show the degree of the infection. 2) The demonstration of specific serum antibodies of the bacterial species responsible for the infection (agglutination technique) is evidence of infection of tissues of the urinary tree, sometimes before the onset of radiological lesions. Furthermore, supervision of the course of the titer of these antibodies assesses the efficacy of the antibiotic treatment undertaken. 3) Using an immunofluorescent technique, the discovery of bacteria antibody immune complexes in the urinary sediment is also a sign of infection of the tissues of the urinary tree.