High Diagnostic Accuracy of Nitrite Test Paired with Urine Sediment can Reduce Unnecessary Antibiotic Therapy.

BACKGROUND: Urinary tract infections (UTIs) are common bacterial infections dominated by lower UTI in women (LUTIW). Symptoms only are insufficient for diagnosis and accordingly, near patient diagnostic tests confidently confirming significant bacteriuria are desirable. The nitrite test (NIT) has low sensitivity, while bacterial and leukocyte counts disjunctively paired in urine sediment microscopy (SED) have high sensitivity. Similar symptomatic cure rates are found post antibiotic vs. placebo therapy in patients with negative cultures. Consequently, prescription on symptoms only implies unnecessary antibiotic therapy. AIMS: to evaluate the diagnostic outcomes of NIT, SED and NIT disjunctively paired with SED (NIT+SED) vs. urine culture, with special focus on bladder incubation time (BIT), and to assess if NIT+SED can reduce unnecessary antibiotic therapy. METHODS: A diagnostic, primary care, multicentre study including 1070 women with symptoms suggestive of lower UTI. RESULTS: Significant bacteriuria was found in 77%. The BIT highly influenced the diagnostic outcomes and the optimal duration was ≥4h with sensitivity of 66, 90 and 95% for NIT, SED and NIT+SED, respectively. SED performed only in NIT negative specimens could reduce unnecessary antibiotics by 10% vs. prescription on symptoms only. The number needed to test with SED to reduce one unnecessary antibiotic course was five patients at BIT ≥4h and six patients at ≤3h or overall. CONCLUSION: The BIT highly influences the diagnostic outcomes with the highest accuracy of NIT+SED. Diagnosis of LUTIW with NIT+SED can reduce unnecessary antibiotic therapy and subsequently decrease antimicrobial resistance. TRIAL REGISTRATION: The Swedish Medical Product Agency 1995 03 01:151:01783/94.

Mecillinam resistance and outcome of pivmecillinam treatment in uncomplicated lower urinary tract infection in women.

Pivmecillinam (PIV) is a first-line antimicrobial for treatment of lower urinary tract infection in women (LUTIW). Mecillinam, the active substance of PIV, is bactericidal mainly against gram-negative uropathogens, whereas gram-positive species are considered intrinsically resistant. However, successful treatment of LUTIW caused by Staphylococcus saprophyticus has been reported, but more rarely for other gram-positive species. The aim of this study was to compare clinical and bacteriological outcome of PIV vs placebo treatment among uropathogens with special focus on mecillinam-resistant isolates. We analysed data from a prospective, multicentre, placebo-controlled, primary health care, therapy study performed in Sweden in 1995­1998 that included 1143 women with symptoms suggestive of LUTIW. Urine cultures were collected and symptoms registered at inclusion and at follow-up visits. Overall, the efficacy of PIV was superior to that of placebo. Clinical and bacteriological outcomes of PIV treatment were similar for S. saprophyticus, Escherichia coli as for most other uropathogens irrespective of their susceptibility to mecillinam. However, the occurrence of enterococci increased nearly fivefold shortly post PIV treatment, although with mild symptoms and a high spontaneous eradication. As susceptibility to mecillinam in vitro did not predict bacteriological and clinical outcome of PIV treatment, we suggest that the present breakpoints for mecillinam should be revised.

Clinical and bacteriological outcome of different doses and duration of pivmecillinam compared with placebo therapy of uncomplicated lower urinary tract infection in women: the LUTIW project.

OBJECTIVE: To analyse associations between symptoms and bacteriuria in uncomplicated lower urinary tract infection in women (LUTIW) and to evaluate outcome of therapy with three different regimens of pivmecillinam or placebo. DESIGN: Prospective, multicentre, randomized, double-blind, and placebo-controlled therapy study. Symptoms registered at inclusion, during therapy and at follow-up visits after 8-10 and 35-49 days. Significant bacteriuria defined according to current European guidelines. SETTING: A total of 18 primary healthcare centres in northern Sweden. Subjects. Women aged 18 years and above with symptoms of urgency, dysuria, supra pubic or loin pain. Main outcome measures. Symptoms and bacteriuria at inclusion and course of symptoms, bacteriuria, and their combinations during and post-therapy. RESULTS: At inclusion, no associations or significant differences were found between symptom scores and bacteriuria, bacterial counts, or species. The 884 patients (77%) with significant bacteriuria were followed up. All pivmecillinam therapies were superior to placebo (p < 0.001). From day six until first follow-up, the mean values of all symptoms were higher and the bacteriological cure was lower at first follow-up in the three days (84%) compared with the seven days regimens (93-94%, p < 0.001). At final follow-up clinical cure was similar in all pivmecillinam regimens (65-72%) as was bacteriological cure (83-89%). Pivmecillinam had few low to mild adverse reactions, comparable to placebo. CONCLUSIONS: Symptoms are not conclusive for diagnosis of LUTIW. Pivmecillinam therapies are superior to placebo and seven days regimens are more efficient than three days. Pivmecillinam 200 mg x 2 x 7 days is recommended as a first-line therapy for LUTIW.

The natural course of uncomplicated lower urinary tract infection in women illustrated by a randomized placebo controlled study.

This prospective, multicentre, randomized, double-blind and placebo controlled study was performed to describe the natural course of uncomplicated lower urinary tract infection (UTI). A total of 1143 women 18 y and above, consulting at 18 primary health care centres in northern Sweden for symptoms suggestive of UTI were included. The symptoms urgency, dysuria, suprapubic pain and loin pain were registered, and urine cultures performed at inclusion and follow-up visits 8-10 d and 5-7 weeks later. Associations between all symptoms and bacteriuria or bacterial counts were unpredictable. Eradication of symptoms and bacteriuria and combinations of them were studied in 288 patients placebo treated for 7 d, of whom 39% dropped out after the first follow-up visit. The spontaneous cure rate of symptoms was 28% after the first week, and 37% had neither symptoms nor bacteriuria after 5-7 weeks. Considering the high dropout rate after the first follow-up visit, the spontaneous cure rate of symptoms and bacteriuria was calculated to 24% at the end of study. We conclude that patient near-laboratory tests are required to establish the diagnosis of lower UTI, and the guidelines for diagnosis of UTI need to be revised.