RESUMO
An approach is described for monitoring urine samples using a portable system based on chromatic techniques and for predicting urinary tract infection (UTI) from the results. The system uses a webcam-computer combination with the screen of a computer visual display unit as a tuneable illumination source. It is shown that the system can operate in a robust manner under ambient lighting conditions and with potential for use as a point of care test in primary care. The present approach combines information on urine liquid concentration and turbidity. Its performance in an exploratory study is compared with microbiological culture of 200 urine samples, of which 79 had bacterial growth >10(5) colony forming unit/millilitre (cfu ml(-1)) indicative of UTI. It is shown that both sensitivity and negative predictive value of 0.92 could be achieved.