[Evaluation of screening methods (catalase, sediment, reactive strip and Gram stain) in urinary tract infection in a Colombian university hospital].

Background: To evaluate the catalase test as a screening method in urinary tract infection (UTI) versus sediment, reactive strip and Gram.
Methods: Two hundred forty-five's stain urine samples were prospectively analyzed in the Hospital Universitario San Ignacio de Bogotá (Colombia). The culture was used as a reference test for the evaluation of the screening parameters in UTI patients.
Results: Of the 245 urine samples 45 were discarded. The remaining 200 urine samples were cultured being 100 positive and 100 negative. The former were analyzed by screening methods. The sensitivity and specificity of the catalase test was 97% and 94%, respectively with a positive predictive value of 94% and negative of 97%. The most frequently isolated microorganism was E. coli (84%), followed by Proteus sp. (6%).
Conclusions: The use of the catalase test in urinary tract infection is a safe, economic and rapid method providing advantages due to its high sensitivity and specificity values, its good correlation with the different parameters evaluated in this study (sediment, strip, Gram's stain), and offers optimum diagnosis in urinary tract infection in developing countries such as Colombia.