Antibiotic duration for treating uncomplicated, symptomatic lower urinary tract infections in elderly women

Biomarkers for risk stratification and antibiotic stewardship in elderly patients

PURPOSE

Optimal treatment of infections in the elderly patients population is challenging because clinical symptoms and signs may be less specific potentially resulting in both, over- and undertreatment. Elderly patients also have a less pronounced immune response to infection, which may influence kinetics of biomarkers of infection.

METHODS

Within a group of experts, we critically reviewed the current literature regarding biomarkers for risk stratification and antibiotic stewardship in elderly patients with emphasis on procalcitonin (PCT).

RESULTS

The expert group agreed that there is strong evidence that the elderly patient population is particularly vulnerable for infections and due to ambiguity of clinical signs and parameters in the elderly, there is considerable risk for undertreatment. At the same time, however, this group of patients is particularly vulnerable for off-target effects from antibiotic treatment and limiting the use of antibiotics is therefore important. The use of infection markers including PCT to guide individual treatment decisions has thus particular appeal in geriatric patients. For the elderly, there is evidence that PCT is a valuable biomarker for assessing the risk of septic complications and adverse outcomes, and helpful for guiding individual decisions for or against antibiotic treatment. There is need for additional educational efforts regarding the concept of "biomarker-guided antibiotic stewardship" for health care providers caring for elderly patients.

CONCLUSION

Use of biomarkers, most notably PCT, has high potential to improve the antibiotic management of elderly patients with possible infection for improving both, undertreatment and overtreatment. Within this narrative review, we aim to provide evidence-based concepts for the safe and efficient use of PCT in elderly patients.

Characteristics of the antibiotic regimen that affect antimicrobial resistance in urinary pathogens

Background

Treatment duration, treatment interval, formulation and type of antimicrobial (antibiotic) are modifiable factors that will influence antimicrobial selection pressure. Currently, the impact of the route of administration on the occurrence of resistance in humans is unclear.

Methods

In this retrospective multi-center cohort study, we assessed the impact of different variables on antimicrobial resistance (AMR) in pathogens isolated from the urinary tract in older adults. A generalized estimating equations (GEE) model was constructed using 7397 Escherichia coli (E. coli) isolates.

Results

Resistance in E. coli was higher when more antibiotics had been prescribed before isolation of the sample, especially in women (significant interaction p = 0.0016) and up to nine preceding prescriptions it was lower for higher proportions of preceding parenteral prescriptions (significant interactions p = 0.0067). The laboratory identity, dying, and the time between prescription and sampling were important confounders (p < 0.001).

Conclusions

Our model describing shows a dose-response relation between antibiotic use and AMR in E. coli isolated from urine samples of older adults, and, for the first time, that higher proportions of preceding parenteral prescriptions are significantly associated with lower probabilities of AMR, provided that the number of preceding prescriptions is not extremely high (≥10 during the 1.5 year observation period; 93% of 5650 included patients).

Trial registration

Retrospectively registered.

Antimicrobial Stewardship and Urinary Tract Infections

Urinary tract infections are the most common bacterial infections encountered in ambulatory and long-term care settings in the United States. Urine samples are the largest single category of specimens received by most microbiology laboratories and many such cultures are collected from patients who have no or questionable urinary symptoms. Unfortunately, antimicrobials are often prescribed inappropriately in such patients. Antimicrobial use, whether appropriate or inappropriate, is associated with the selection for antimicrobial-resistant organisms colonizing or infecting the urinary tract. Infections caused by antimicrobial-resistant organisms are associated with higher rates of treatment failures, prolonged hospitalizations, increased costs and mortality. Antimicrobial stewardship consists of avoidance of antimicrobials when appropriate and, when antimicrobials are indicated, use of strategies to optimize the selection, dosing, route of administration, duration and timing of antimicrobial therapy to maximize clinical cure while limiting the unintended consequences of antimicrobial use, including toxicity and selection of resistant microorganisms. This article reviews successful antimicrobial stewardship strategies in the diagnosis and treatment of urinary tract infections.

Uncomplicated urinary tract infections

BACKGROUND

Urinary tract infections (UTIs) are among the most common types of bacterial infection in outpatient medicine. Rising rates of antibiotic resistance and a better understanding of the ecological adverse effects (collateral damage) of antibiotics warrant a reevaluation of the treatment recommendations for uncomplicated UTI. The new S3 guideline contains updated recommendations.

METHODS

The new S3 guideline is based on a review of publications on uncomplicated UTI retrieved by a systematic search of the Medline and Cochrane Library databases. Guidelines from abroad were also considered in the review.

RESULTS

Uncomplicated UTI is classified as either uncomplicated cystitis (UC) or uncomplicated pyelonephritis (UP). The choice of a suitable antibiotic is determined by the following main criteria: the patient's individual risk profile and prior antibiotic treatment, if any; the spectrum of pathogens and antibiotic susceptibility; the proven efficacy of the antibiotic; the ecological adverse effects (collateral damage) of antimicrobial therapy; the side effects for the patient under treatment. On the basis of these criteria, co-trimoxazole/trimethoprim and fluoroquinolones can no longer be recommended as first-line empirical treatment for UC. Rather, the new recommended treatment of first choice consists of fosfomycin-trometamol, nitrofurantoin, or pivmecillinam. High-dose fluoroquinolones are still recommended, however, as first-line oral treatment for UP. Asymptomatic bacteriuria should only be treated in exceptional situations such as pregnancy or before urological procedures that will probably injure the mucosa of the urinary tract.

CONCLUSION

The new S3 guideline on uncomplicated UTI incorporates a forward-looking approach to the use of antibiotics in treating this common type of infection. It is intended to bring about a sustained improvement in the quality of care.

Increasing resistance to quinolones: A four-year prospective study of urinary tract infection pathogens

A four-year prospective study was carried out to determine the incidence and rate of development of resistance by common urinary tract infection (UTI) pathogens to quinolone antimicrobial agents. Results show that there is high intrinsic resistance to the quinolones among strains of Pseudomonas aeruginosa (43.4%), Escherichia coli (26.3%), and Proteus spp. (17.1%). Over four years, rising rates of resistance were observed in P. aeruginosa (14.6% increase), Staphylococcus aureus (9.8%), and E. coli (9.7%). The highest potency was exhibited by ciprofloxacin (91.2%), levofloxacin (89.2%), and moxifloxacin (85.1%), while there were high rates of resistance to nalidixic acid (51.7%) and pefloxacin (29.0%). Coliforms, particularly E. coli (>45%), remain the most prevalent causative agents of UTI while females within the age range of 20-50 years were most vulnerable to UTI.

Meta-analyses in prevention and treatment of urinary tract infections

Urinary tract infections (UTI) are common, and complications result in significant morbidity and mortality and also consume resources. This overview summarizes the current evidence for the prevention and treatment of UTI in adults and children from meta-analyses. The quality and applicability of this evidence in clinical practice for different patient groups is discussed. Suggestions are made for future research, because it is apparent that there are evidence gaps for particular subgroups of people.

Urinary tract infections

Urinary tract infection (UTI), with its diverse clinical syndromes and affected host groups, remains one of the most common but widely misunderstood and challenging infectious diseases encountered in clinical practice. Antimicrobial resistance is a leading concern, with few oral options available to treat infections caused by Gram-negative organisms resistant to trimethoprim-sulfamethoxazole and fluoroquinolones, especially for patients with upper tract disease. Efforts should be made not to detect or treat asymptomatic bacteriuria and funguria; to ensure an appropriate duration of therapy for symptomatic infections; and to limit the use of broad-spectrum agents, especially fluoroquinolones, if narrower spectrum agents are available. Further research is needed regarding rapid diagnosis of UTI, accurate presumptive identification of patients with resistant pathogens, and development of new antimicrobials for drug-resistant UTI.

Errors in search strategies were identified by type and frequency

OBJECTIVE

Errors in the electronic search strategy of a systematic review may undermine the integrity of the evidence base used in the review. We studied the frequency and types of errors in reviews published by the Cochrane Collaboration.

STUDY DESIGN AND SETTING

Data sources were MEDLINE searches from reviews in the Cochrane Library, Issue 3, 2002. To be eligible, systematic reviews must have been of randomized or quasi-randomized controlled trials, reported included and excluded studies, and used one or more sections of the Cochrane Collaboration's Highly Sensitive Search Strategy. MEDLINE search strategies not reported in enough detail to be assessed or that were duplicates of a search strategy already assessed for the study were excluded. Two librarians assessed eligibility and scored the eligible electronic search strategies for 11 possible errors. Dual review with consensus was used.

RESULTS

Of 105 MEDLINE search strategies examined, 63 were assessed; 31 were excluded because they were inadequately reported, and 11 were duplicates of assessed search strategies. Most (90.5%) of the assessed search strategies contained > or =1 errors (median 2, interquartile range [IQR] 1.0-3.0). Errors that could potentially lower recall of relevant studies were found in 82.5% (median 1, IQR 1.0-2.0) and inconsequential errors (to the evidence base) were found in 60.3% (median 1, IQR 0.0-1.0) of the search strategies. The most common search errors were missed MeSH terms (44.4%), unwarranted explosion of MeSH terms (38.1%), and irrelevant MeSH or free text terms (28.6%). Missed spelling variants, combining MeSH and free text terms in the same line, and failure to tailor the search strategy for other databases occurred with equal frequency (20.6%). Logical operator error occurred in 19.0% of searches.

CONCLUSION

When the MEDLINE search strategy used in a systematic review is reported in enough detail to allow assessment, errors are commonly revealed. Additional peer review steps are needed to ensure search quality and freedom from errors.

Can electronic search engines optimize screening of search results in systematic reviews: an empirical study

BACKGROUND

Most electronic search efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG and Ovid. Our objective is to test the ability of an Ultraseek search engine to rank MEDLINE records of the included studies of Cochrane reviews within the top half of all the records retrieved by the Boolean MEDLINE search used by the reviewers.

METHODS

Collections were created using the MEDLINE bibliographic records of included and excluded studies listed in the review and all records retrieved by the MEDLINE search. Records were converted to individual HTML files. Collections of records were indexed and searched through a statistical search engine, Ultraseek, using review-specific search terms. Our data sources, systematic reviews published in the Cochrane library, were included if they reported using at least one phase of the Cochrane Highly Sensitive Search Strategy (HSSS), provided citations for both included and excluded studies and conducted a meta-analysis using a binary outcome measure. Reviews were selected if they yielded between 1000-6000 records when the MEDLINE search strategy was replicated.

RESULTS

Nine Cochrane reviews were included. Included studies within the Cochrane reviews were found within the first 500 retrieved studies more often than would be expected by chance. Across all reviews, recall of included studies into the top 500 was 0.70. There was no statistically significant difference in ranking when comparing included studies with just the subset of excluded studies listed as excluded in the published review.

CONCLUSION

The relevance ranking provided by the search engine was better than expected by chance and shows promise for the preliminary evaluation of large results from Boolean searches. A statistical search engine does not appear to be able to make fine discriminations concerning the relevance of bibliographic records that have been pre-screened by systematic reviewers.

The future challenges facing the development of new antimicrobial drugs

The emergence of resistance to antibacterial agents is a pressing concern for human health. New drugs to combat this problem are therefore in great demand, but as past experience indicates, the time for resistance to new drugs to develop is often short. Conventionally, antibacterial drugs have been developed on the basis of their ability to inhibit bacterial multiplication, and this remains at the core of most approaches to discover new antibacterial drugs. Here, we focus primarily on an alternative novel strategy for antibacterial drug development that could potentially alleviate the current situation of drug resistance--targeting non-multiplying latent bacteria, which prolong the duration of antimicrobial chemotherapy and so might increase the rate of development of resistance.