Bacteria are not the same as infection
Asymptomatic bacteriuria means bacteria in the urine without symptoms of a urinary infection. The Commission’s aged care guidance states that a very high proportion of older people have it, and warns that treating a positive dipstick result can lead to antibiotics being given unnecessarily 4.
The Infectious Diseases Society of America has advised since 2005 that asymptomatic bacteriuria should not be screened for or treated in older women and men, or in people with indwelling catheters. Its 2019 update notes that treating it is an important contributor to inappropriate antibiotic use, which promotes resistance 16.
Why the dipstick misleads
A dipstick or a culture shows what is in the urine. It cannot show whether those bacteria are causing the person’s illness. The Commission’s guidance says that a urine culture alone does not confirm a urinary infection, that the person’s symptoms and signs do, and that dipstick testing should be done only when symptoms and signs suggest a urinary infection 4.
In a US cohort of 551 nursing home residents without catheters, only 37% of episodes of suspected urinary infection that were tested had both bacteria and white cells in the urine. Painful urination, a change in the character of the urine and a change in mental state were each linked with a positive result. Most residents had only one of these features, and for them the diagnosis stayed uncertain 15. This was an observational study.
Information that helps the treating clinician
When a urinary infection is suspected, these details make the call more useful than a dipstick result.
-
Urinary symptoms. New pain or burning on passing urine, new urgency or frequency, new or worse incontinence, or visible blood.
-
Signs of wider illness. Fever or feeling cold, shaking, new confusion or drowsiness, faster breathing, or a fall.
-
Catheter. Whether there is an indwelling catheter, and when it was last changed.
-
Other possible causes. Constipation, poor drinking, new medicines, chest symptoms or pain elsewhere.
-
The resident’s goals of care. What the resident has said about treatment and hospital transfer.
Reducing unnecessary treatment: the evidence
Graded on randomised evidence in nursing homes, except where stated.
A diagnostic and treatment algorithm for suspected urinary infection, introduced with education for nurses and doctors
Promising, not yet provenFewer antibiotic courses for suspected urinary infection, with no difference in hospital admissions or deaths.
The evidence
In a cluster randomised trial in 24 nursing homes in Canada and the US (4,217 residents), courses for suspected urinary infection fell from 1.59 to 1.17 per 1,000 resident-days. Total antibiotic use did not differ significantly, and there was no significant difference in hospital admissions or deaths 17.
In practice
One trial, published in 2005 17.
Treating asymptomatic bacteriuria in older adults
Not supportedRecommended against for older women and men and for people with catheters.
The evidence
Graded on the Infectious Diseases Society of America guideline, which has advised against screening and treatment in these groups since 2005 16.
In practice
The guideline review, not individual trials, is summarised here 16.
Cranberry capsules
Not supportedNo reduction in bacteria plus white cells in the urine of older women in nursing homes.
The evidence
A double-blind trial of 185 women in 21 US nursing homes found no difference after one year (29.1% against 29.0%), and no significant difference in symptomatic infections, deaths, hospital admissions or antibiotic use 18.
Related pages on this site
Sources cited on this page
- 4 Australian Commission on Safety and Quality in Health Care. Guidance for implementation of the Antimicrobial Stewardship Clinical Care Standard in aged care. Sydney: ACSQHC; November 2024. View source
- 15 Juthani-Mehta M, Quagliarello V, Perrelli E, Towle V, Van Ness PH, Tinetti M. Clinical features to identify urinary tract infection in nursing home residents: a cohort study. J Am Geriatr Soc. 2009;57:963–70. (Prospective observational cohort; 551 residents without catheters in five US nursing homes.) View source
- 16 Nicolle LE, Gupta K, Bradley SF, et al. Clinical practice guideline for the management of asymptomatic bacteriuria: 2019 update by the Infectious Diseases Society of America. Clin Infect Dis. 2019;68:e83–110. (Checked at abstract level.) View source
- 17 Loeb M, Brazil K, Lohfeld L, et al. Effect of a multifaceted intervention on number of antimicrobial prescriptions for suspected urinary tract infections in residents of nursing homes: cluster randomised controlled trial. BMJ. 2005;331:669. (24 nursing homes in Ontario and Idaho; 4,217 residents.) View source
- 18 Juthani-Mehta M, Van Ness PH, Bianco L, et al. Effect of cranberry capsules on bacteriuria plus pyuria among older women in nursing homes: a randomized clinical trial. JAMA. 2016;316:1879–87. (185 women in 21 US nursing homes.) View source
See every source cited across the deteriorating resident section →
Written by Dr Josh Hatch, FRACGP. General information only, reflecting his reading of the published evidence as at November 2026. It is not individual medical advice, does not create a doctor–patient relationship, and must not be used to start, stop or change any treatment, and it does not set escalation rules for any facility. Antibiotic choices and doses follow current prescribing guidelines and local advice. Evidence, Australian regulatory requirements and local services change — always confirm current advice with the treating GP and the facility’s own procedures.
This is general education, not a clinical protocol. The doctors who practise with Umbrella Aged Care are independent general practitioners, and each makes their own clinical decisions with the resident and family. Your GP’s advice for an individual may differ from what is written here. If it does, please ask them to talk it through with you.