Recurrent Urinary Tract Infections
Recurrent urinary tract infection (RUTI) is defined as at least three episodes of culture-positive urinary infections in the last 12 months, or two episodes in last 6 months. The incidence of both UTI and asymptomatic bacteriuria increases with age. Factors predisposing postmenopausal women to recurrent UTI include lack of estrogen (causing change in vaginal pH and loss of lactobacilli), UI, urogenital surgery, presence of cystocele, increased post-void residual urine and genetic factors such as non-secretor (of histo-blood group antigens) status and history of UTI before menopause. Functional status and catheterization are the most important risk factors in elderly institutionalized women. Diabetes and sexual activity have also been noted as risk factors.[72,73]
Relevant history taking and clinical examination should be supplemented by investigations such as urine dipstick for protein, nitrites, leucocyte esterase, blood (specificity 92–100%, sensitivity 19–48%) and urine cultures especially in the background of RUTI. Screening for diabetes should be considered in presence of suggestive history and glucosuria on urine dipstick. The presence of hematuria (gross or persistent microscopic), pneumaturia or fecaluria, pyelonephritis, obstructive symptoms, infection with urea-splitting bacteria, clinical impression of persistent infection or urinary calculi warrant an ultrasound scan of the renal tract and urological evaluation including cystoscopy. However, no list is totally comprehensive and individual patient circumstances have to be considered. The role of routine cystoscopy for RUTI has been debated and there are no studies specifically addressing the postmenopausal RUTI but on an average 8% cases of RUTI have positive findings at cystoscopy in all age groups but this is more in the age group >50 years.
Although there is no clear evidence that lack of estrogen per se causes an increase in UTI in post-menopausal women, studies have revealed significant reduction of UTI by using vaginal estrogens over placebo especially where there is evidence of vaginal atrophy. The vaginal cream appears to be the most cost-effective way of delivering the estrogen, however, the optimal treatment schedule and duration of treatment are less clear.[77,78]
Cranberry products have been widely used as preventive measure against RUTI. Although no definite mechanism of action is known, research suggests that cranberry prevent bacterial adhesion to uroepithelium. However, a recent Cochrane review failed to note any significant benefit from cranberry products (juice, tablets and capsules).
The Cochrane review of antibiotic prophylaxis indicated that antibiotics are better than placebo in preventing RUTI in both pre and postmenopausal women. However, the benefit was only for the duration of antibiotic intake. The choice of antibiotic is depends on local patterns of drug-resistance, as no drug has any significant superiority. The duration of treatment is not clear but the need for prophylaxis should be re-evaluated after 6–12 months. A cautious approach to drug treatment is advisable in the presence of multiple comorbidity, polypharmacy and declining renal function which are common in the elderly women. For treatment of uncomplicated, symptomatic lower urinary tract infections in elderly women, the optimal duration of antibiotic treatment is 3–6 days.
Post-coital prophylaxis and self-initiated antibiotic therapy are also successful strategies in selected group of patients with RUTI.
Expert Rev of Obstet Gynecol. 2013;8(6):625-637. © 2013 Expert Reviews Ltd.