[Relevance of the detection of Streptococcus pneumoniae antigen in human urine in the diagnosis of lower respiratory tract infections].

Background and Objective: Techniques membrane antigen immunochromatographic detecting in urine the pneumococcal polysaccharide C, have developed significantly, increasing requests for antigenuria to clinical microbiology laboratories. We evaluated the impact of the application of this test in the diagnosis of infections of lower respiratory tract.
Patients and Method: Six hundred and sixteen determinations were performed by antigenuria BinaxNOW(®) S. pneumoniae in as many patients over 14 years admitted to the Hospital Universitario Virgen de las Nieves (Granada) between November 2010 and March 2011.
Results: In 91.1% of patients who were determined antigenuria the presence of respiratory symptoms justified the request. Only 8.4% of 616 antigenurias performed were positive. S. pneumoniae was isolated from the respiratory sample culture in 8 of these 52 patients. In 29.8% of patients the diagnosis of lower respiratory tract infection was based on clinical, radiological and/or analytical, as antigenurias were negative and did not involve any other additional microbiological test.
Conclusions: We believe that this technique should be used in a complementary manner, and never to the detriment of other microbiological tests, especially in hospitalized patients.