Page 50 - GALENIKA MEDICAL JOURNAL

UNCOMPLICATED URINARY TRACT

INFECTIONS IN THE ELDERLY

Nada Dimković 1 reported by the patient. However, the threshold for bacteri-
1 Faculty of Medicine, University of Belgrade, Serbia uria is not clearly defined or standardized by microbiology
laboratories. Many laboratories define a threshold of 10
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CFU/mL (colony-forming units of bacteria) as the cutoff, but
Corresponding author:
this may lead to missing some infections, so a lower thres-
Prof. dr Nada Dimković hold (10 CFU/mL) is advised. According to the criteria of the
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Medicinski fakultet Univerziteta u Beogradu, Dr Subotića Infectious Disease Society of America (IDSA), asymptomatic
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starijeg 8, Beograd, Srbija bacteriuria (ASB) is defined when patients have ≥ 10 CFU/
mL or more than one bacterial species in two consecutive
dim@eunet.rs
urine samples in women and one sample in men, in the ab-
sence of clinical signs and symptoms characteristic of UTI .
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Abstract Epidemiology
A healthy urinary tract is not a sterile environment The incidence of ASB increases with age and reaches
but is inhabited by diverse microorganisms that 20% in females older than 80 years. In healthy males, ASB
change according to environmental factors and the is not typical before the age of 60, while the incidence is
patient’s condition. Elderly patients are predisposed to between 5 to 10% in males older than 80 years . Sympto-
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urinary tract infections and asymptomatic bacteriuria, matic infections are not directly correlated with ASB, nor
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and distinguishing between these two conditions are incidental renal impairment and hypertension . Elderly
is challenging. They are specific in several issues: women have a higher frequency of UTIs compared to men,
the pathogenesis of infection and causative agents, and this difference is more pronounced than in younger in-
dividuals.
diagnostic procedures, applied therapy, and preventive
measures. Proper interpretation of symptoms, sampling Individuals residing in long-term care facilities for the
of materials for analysis, and interpretation of results are elderly have a higher incidence of ASB (25-50% in women
of great importance. Correct procedures allow sparing and 15-40% in men) compared to older adults treated on
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patients from unnecessary treatment and complications an outpatient basis . Bacteriuria is a dynamic phenomenon:
among individuals diagnosed with ASB, one-third will have a
of antibiotic therapy, as well as reducing bacterial negative urine culture within 3 to 6 months, while one-third
resistance. of patients with initially negative cultures will develop bacte-
riuria. ASB in individuals residing in long-term care facilities
Keywords: urinary tract infections, elderly individuals, is not associated with poor survival, but it is often the cause
therapy
of unnecessary antibiotic use, leading to increased inciden-
ce of infections caused by Clostridium difficile and other ne-
gative effects of antibiotic therapy.
Introduction
Symptomatic UTI is the second most common infection
Urinary tract infections (UTIs) are responsible for among these individuals, with a reported frequency ranging
approximately 15.5% of hospitalizations due to infectious from 0.5 to 1 per 1.000 hospital days . In elderly individu-
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diseases in individuals over the age of 65 (right after pneu- als capable of providing valid symptom data, distinguishing
monia) and are the cause of death in about 6% of patients . between UTI and ASB is relatively easy. However, in those
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UTIs can be classified, in younger individuals, based on with cognitive impairment, distinguishing ASB from UTI is
several criteria: based on location (cystitis, pyelonephritis), challenging. Approximately 45-56% of all bacteremias in
recurrence tendency (intermittent, recurrent), symptomato- individuals from long-term care facilities are attributed to
logy (asymptomatic, symptomatic), and based on the pre- urinary origin, but this mostly pertains to individuals with
sence of complications (complicated and uncomplicated). indwelling catheters.
In individuals with a normal genitourinary tract, these infe-
ctions are termed uncomplicated UTIs, while structural and Hospitalizations due to acute pyelonephritis are more
functional abnormalities of the urinary tract lead to com- common with increasing age, while recurrent UTIs are
plicated UTIs. The gold standard for diagnosing UTI is the more frequent mainly in individuals with complicated infe-
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presence of pathogens in the urine along with symptoms ctions. Mortality due to UTI is uncommon . An analysis of

48 DOI: 10.5937/Galmed2409055D