Asymptomatic bacteriuria in older adults: the most fragile women are prone to long-term colonization

Abstract

Background The diagnosis of urinary tract infections (UTIs) in institutionalized older adults is often based on vague symptoms and a positive culture. The high prevalence of asymptomatic bacteriuria (ABU), which cannot be easily discriminated from an acute infection in this population, is frequently neglected, leading to a vast over-prescription of antibiotics. This study aimed to identify subpopulations predisposed to transient or long-term ABU. Methods Residents in a long-term care facility were screened for ABU. Mid-stream urine samples were collected during two sampling rounds, separated by 10 weeks, each consisting of an initial and a confirmative follow-up sample. Results ABU occurred in approximately 40% of the participants and was mostly caused by Escherichia coli . Long-term ABU (> 3 months) was found in 30% of the subjects. The frailest women with urinary incontinence and dementia had drastically increased rates of ABU and especially long-term ABU. ABU was best predicted by a scale describing the functional independence of older adults. Conclusions Institutionalized women with incontinence have ABU prevalence rates of about 80% and are often persistent carriers. Such prevalence rates should be considered in clinical decision making as they devalue the meaning of a positive urine culture as a criterion to diagnose UTIs. Diagnostic strategies are urgently needed to avoid antibiotic overuse and to identify patients at risk to develop upper UTI. Electronic supplementary material The online version of this article (10.1186/s12877-019-1181-4) contains supplementary material, which is available to authorized users.

Antimicrobial Susceptibility Pattern for Community-Acquired Uro-pathogens among UTI Geriatric Patients

“…Out of 180 urine samples collected during this study, 82 (45.5%) patients had urine samples with significant bacteriuria and asymptomatic bacteriuria was more prevalent (71%), specifically in males more than females; our findings confirmed by Nicolle et al [21] who concluded that asymptomatic bacteriuria in older is common. The majority of participants were male (61%), this is more or less near to Biggel et al [22], although it conflicts with previous studies [23,24] and a general knowledge state that the prevalence of bacteriuria is approximately 3 times higher in female than male elderly populations. A general conclusion verified that female patients due to their genital anatomy were more predisposed to urinary infection.…”

Horizontally acquired papGII-containing pathogenicity islands underlie the emergence of invasive uropathogenic Escherichia coli lineages

“…Conversely, a substantial fraction of the present cystitis and ABU isolates, including strains that asymptomatically colonized the urinary tract over months 53 , carried papGII , without causing invasive infection. Apart from possible stochastic effects, this may reflect in part the known variation in host susceptibility to UTI in relation to specific host genetic polymorphisms 54 ; conceivably, these isolates’ corresponding source hosts may have been more resistant to developing invasive UTI.…”

“…Most of the isolates originated from female participants (41/42) with incontinence (39/41). A comprehensive analysis of bacteriology and risk factors associated with ABU at one of the two collections sites was published previously 53 .…”

Development of a Tailored, Complex Intervention for Clinical Reflection and Communication about Suspected Urinary Tract Infections in Nursing Home Residents

“…Asymptomatic bacteriuria is the presence of bacteria in a urine sample from a patient that shows no signs or symptoms originating from the urinary tract [ 12 ]. Positive urine tests in the nursing home population are common because the frequency of asymptomatic bacteriuria varies between 40–80% among nursing home residents [ 9 , 13 ]. The evidence states that this patient group will not benefit from antibiotic treatment of asymptomatic bacteriuria.…”