The clinical relevance of these observations is unclear. Symptoms, Signs, and Diagnosis Many patients are asymptomatic. Symptoms that may occur include dysuria, urinary frequency, incontinence of recent onset, flank pain, and fever. Confusion and delirium are often attributed to UTI, although without high fever or sepsis, uncomplicated UTI is unlikely to cause serious central nervous system dysfunction. However, bladder puncture may be more difficult to perform in elderly patients, and straight bladder-catheterized specimens often have to suffice.
Rapid tests can provide a semiquantitative determination of bacteriuria.
The best is the nitrite test, in which the conversion of nitrate to nitrite by bacteria in the urine is demonstrated by color change on a dipstick. This test has a high degree of sensitivity and specificity but does not demonstrate bacteriuria caused by Pseudomonas sp, staphylococci, or enterococci, which are incapable of reducing nitrate to nitrite. Quantitative urine cultures can be performed in bacteriology laboratories. Quantitative urine cultures also identify the species involved and determine antibiotic susceptibility. A positive dip-slide can later be sent to a bacteriology laboratory for identification of species and determination of antibiotic susceptibility.