Symptomatic urinary tract infection in women in primary health care. Bacteriological, clinical and diagnostic aspects in relation to host response to infection.

OBJECTIVE

To evaluate rapid diagnostic tests for bacteriuria in women with symptoms of urinary tract infection (UTI), and to analyse bacteriological and clinical findings in relation to host response to infection.

DESIGN

Prospective study of symptomatic UTI in women.

SETTING

Primary health care centres.

PATIENTS

819 women with signs and symptoms suggestive of UTI.

MAIN OUTCOME MEASURES

History of UTI and clinical findings were recorded. After randomization but before antibiotic treatment, urine specimens were analysed for pyuria by sediment microscopy and for nitrite using a test strip, and cultures were performed. The systemic inflammatory response was assessed by C-reactive protein (CRP), erythrocyte sedimentation rate, and total white blood cell count.

RESULTS

The combined use of tests for pyuria and nitrite resulted in a high sensitivity (0.93) and efficacy (0.85) when the prevalence of bacteriuria was 0.89. Escherichia coli and Staphylococcus saprophyticus accounted for 93% of the urinary isolates. Significantly more patients infected with S. saprophyticus than E. coli complained of dysuria (p < 0.05), frequency (p < 0.05) or flank pain (p < 0.01). CRP agreed best with the clinical diagnosis of acute pyelonephritis.

CONCLUSIONS

In women with a high probability of bacteriuria, i.e. those with symptoms of lower UTI, examination for pyuria and urinary nitrite offers high diagnostic efficacy. If either or both tests are positive urine cultures can be omitted.