Diagnosis and Treatment UTI

Early diagnosis and treatment of UTI are essential for preventing permanent kidney damage. Screening of high-risk groups and attèntion to care of patients with indwelling catheters are important measures. Pregnant women and persons with diabetes or renal problems who are at risk for developing UTIs usually can be man aged in the physician’s office. 

The diagnosis of UTI usually is based on symptoms and on examination of the urine for the presence of  microorganisms. When necessary, x-ray films, ultra sonography, and CT and renal scans are used to identify contributing factors, such as obstruction. 

Bacteriuria, or the presence of bacteria in the urine, often is used in diagnosing UTIs. The source of bacteria in the urine can be contamination of the urine specimen, simple colonization of the urinary tract, or bacterial invasion of urinary structures. Colonization usually is defined as the multiplication of microorganisms in or on a host without apparent evidence of invasiveness or tis sue injury A commonly accepted criterion for diagnosis of a UTI is the presence of more than 100,000 (105) organ isms per 1 ml of urine. The accuracy of the diagnosis is strengthened if such numbers are found in two consecutive urine specimens and if the bacteria are of a single type. Contaminated urine specimens commonly contain several types of microorganisms. 

Care is needed in collecting urine specimens representative of bladder urine. Specimens that -are kept for longer than 1 hour must be refrigerated to prevent the contaminating organisms from multiplying. The use of catheterized urine specimens, once common, have largely been replaced with clean-voided specimens. To obtain a dean-voided specimen, the area around the urethra is carefully cleanséd and a midstream specimen is obtained by having the person void directly into a sterile container. 

This method usually is adequate and eliminates the risk of introducing microorganisms into the bladder during insertion of a catheter. In infants and sometimes in other age groups, suprapubic aspiration may be done to obtain a sample of bladder urine. 

In addition to the bacterial count, the urine leukocyte count is used. Pyuria (>10 1eukocytes/ð of uncentrifuged urine) indicates host injury rather than asymptomatic bacterial colonization. Immunofluores cence studies may be done to determine whether the infection involves the upper urinary tract. These tests are expensive and usually are not done routinely. Detailed identification and antibiotic sensitivity tests often are done in cases of chronic infection.