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. 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. 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. 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.

Objective To determine the rate and appropriateness of antibiotic prescribing for acutely ill children in ambulatory care in high-income countries. Design On 10 February 2021, we systematically searched articles published since 2000 in MEDLINE, Embase, CENTRAL, Web Of Science and grey literature databases. We included cross-sectional and longitudinal studies, time-series analyses, randomised controlled trials and non-randomised studies of interventions with acutely ill children up to and including 12 years of age in ambulatory care settings in high-income countries. Pooled antibiotic prescribing and appropriateness rates were calculated using random-effects models. Meta-regression was performed to describe the relationship between the antibiotic prescribing rate and study-level covariates. Results We included 86 studies comprising 11 114 863 children. We found a pooled antibiotic prescribing rate of 45.4% (95% CI 38.2% to 52.8%) for all acutely ill children, and 85.6% (95% CI 73.3% to 92.9%) for acute otitis media, 37.4% (95% CI 30.9% to 44.3%) for respiratory tract infections, and 40.4% (95% CI 29.9% to 51.9%) for other diagnoses. Considerable heterogeneity can only partly be explained by differences in diagnoses. The overall pooled appropriateness rate is 68.5% (95% CI 55.8% to 78.9%, I²=99.8%; 19 studies, 119 995 participants). 38.3% of all prescribed antibiotics were aminopenicillins. Conclusions Antibiotic prescribing rates for acutely ill children in ambulatory care in high-income countries remain high. Large differences in prescription rates between studies can only partly be explained by differences in diagnoses. Better registration and further research are needed to investigate patient-level data on diagnosis and appropriateness.

Despite the high efficacy of the BNT162b2 vaccine in the general population, data on its immunogenicity among frail elderly individuals are limited. Recently, levels of anti-SARS-CoV-2 spike IgG antibodies and serum neutralization titers were confirmed as good immune markers of protection against the virus, with evidence showing a reverse correlation between these two parameters and susceptibility to infection. Here we analyzed sera from 138 nursing home residents (median age of 88.9 years) and 312 nursing home staff (median age of 50.7 years) to determine the humoral response to two doses of the BNT162b2 vaccine, and found markedly decreased serum anti-spike antibody levels and neutralization titers in the nursing home resident (NHR) group, with over 11% non-responders compared to only 1.3% among the controls. Moreover, three months post-vaccination, a significant decrease in antibody titers was observed in COVID-19-naive nursing home residents. Subsequent flow cytometry and interferon gamma secretion analyses indicated that antibody non-responders among NHRs also failed to mount cellular responses. The presented data emphasize that additional measures are needed in the population of frail elderly individuals. Given the high proportion of non-responders among NHRs, continued monitoring should be considered in this group.