Introduction: It is typical to look for UTI in delirious elderly patients, despite a high prevalence of asymptomatic bacteriuria (ASB) in this population. A common presentation of infection is delirium, which often has a non-specific and multifactorial etiology. Therefore, when bacteriuria is present with delirium in the absence of urinary symptoms, physicians prescribe antibiotics for the suspected UTI-induced delirium. We set to determine whether antibiotic treatment in the elderly presenting with delirium in the presence of ASB resulted in resolution of delirium. Methods: Literature searches were performed in MEDLINE, EMBASE, CINAHL and Cochrane Library. Abstracts were independently reviewed by two authors for decision to include for full-text review. Inclusion criteria included female gender, >65 years of age, presenting in an acute care setting with delirium and ASB. The primary outcome was resolution of delirium. The secondary outcomes were mortality, frequency of side effects from antibiotics, length of hospital stay and readmission for delirium. Results: 930 abstracts published from 1946-2017 were screened, and 42 were included for full text review. No studies were eligible for inclusion in the systematic review, as none addressed the primary outcome. One study addressed the outcomes of poor functional recovery after delirium and the rate of improvement of delirium symptoms after presentation of delirium with ASB. Conclusion: Even though current guidelines recommend against treatment of ASB, no guideline states whether ASB should be treated in elderly patients with delirium. Little evidence exists to elucidate whether treating delirious patients with ASB results in improvement in outcomes. Future studies should focus on demonstrating the relationship between resolution of delirium with antibiotic treatment. This will clarify whether delirium is a true symptom of ASB and whether treatment results in faster resolution of delirium.

An observational study was conducted to describe the epidemiology of bacteriuria and candiduria in the intensive care unit (ICU), and the occurrence of blood stream infection (BSI) associated with ICU-acquired positive urine culture. Between 2006 and 2011, 444 episodes of either bacteriuria or candiduria defined by positive urine culture (microorganisms ⩾105 c.f.u./ml) occurred in 406 patients. Three hundred and seventy-seven (85%) were hospital-acquired including 221 which were ICU-acquired (6·4 ± 0·8 episodes/1000 ICU days). Escherichia coli was the most common bacteria of both community- and ICU-acquired bacteriuria/candiduria (49·2% and 29%, respectively). Candida spp. represented 55% (129/236) of pathogens responsible for ICU-acquired positive urine cultures. Patients with ICU-acquired candiduria had greater illness severity at ICU admission than those with ICU-acquired bacteriuria (APACHE III score 79 ± 25 vs. 66 ± 31, P = 0·0015). BSI associated with ICU-acquired positive urine culture occurred in 0·15/1000 ICU days and was more often due to Candida. In this study, Candida was the most common pathogen responsible for ICU-acquired positive urine cultures and illness severity was a risk factor for candiduria in the study population.