Encuesta sobre los métodos de diagnóstico microbiológico de la infección urinaria

The urinary tract infection (UTI), a highly prevalent disease, must be confirmed by microbiological diagnosis. The Clinical Microbiology Committee of the Chilean Infectious Diseases Society did a retrospective survey in order to know the methodology and diagnostic criteria employed for UTI microbiological diagnosis by a representative number of clinical laboratories. The information about 49.632 urine cultures collected was obtained from fifteen public hospitals and private laboratories. All the laboratories employed the same criteria for UTI diagnosis: a microbial count > 100.000 cfu/ml. We couldn't analize lesser counts, (data was not available neither for sample collecting methods, concomitant microscopic urine analysis -urinary sediment- nor clinical symptoms). Utilizing this diagnostic criteria the yield varied among 2.3% in men and 33% in women, with more dispersed rates in children. Only the 13% of institutions processed the urine samples knowing the time transcurred since the sample collection. All the laboratories employed the same criteria to consider as contaminated a culture with: > 3 microorganisms; some of them registered 17% of contamination. Although this survey was retrospectively done diminishing the quality of the situation diagnosis, it motivated the Clinical Microbiology Advisory Committee to prepare Guidelines for the Microbiological Diagnosis of UTI.