Asymptomatic bacteriuria and inflammatory response to urinary tract infection of elderly ambulatory women in nursing homes

Background. Bacteriuria greater than or equal to 10(5) CFU/ml is evidence o f urinary tract infection in the absence of associated signs or symptoms. T he presence of pyuria with asymptomatic bacteriuria established the respons e of elderly women against microorganisms capable of causing invasiveness o r tissue injury of the urinary tract. Methods, The association between bacteriuria and pyuria was determined in 1 78 elderly, ambulatory women without symptoms of urinary tract infection in seven nursing homes. Urine culture results were subsequently analyzed in c onjunction with absolute leukocyte count in urine. In this cross-sectional study, asymptomatic bacteriuria in elderly women was classified with and wi thout pyuria, Results. The prevalence of asymptomatic bacteriuria was found in 44 (24.7%) elderly women. The presence of pyuria had a sensitivity of 63.6% for bacte riuria and a specificity of 91%. The positive predictive value for the pres ence of pyuria predicting those with bac teriuria was 70%, and the negative predictive value for the absence of pyuria predicting those without bacter iuria was 88.4%. Escherichia coli was the most common organism isolated in 81.8% of the women. Conclusions. Bacteriuria greater than or equal to 10(5) CFU/ml associated w ith pyuria was detected in 77% of elderly women with asymptomatic urinary t ract infections, Bacteriuria of <10(5) CFU/ml with pyuria proves less sensi tive as an indicator of urinary tract infection. Elderly women with pyuria but without bacteriuria should be studied for other causes of urinary tract inflammation. (C) 1999 IMSS. Published by Elsevier Science Inc.