Urinary Tract Infections in the Elderly: Challenges and New Diagnostic Solutions

The global population is steadily aging. It is projected that by 2025, the proportion of elderly people in Europe will increase from 20% to 28%. Demographers define elderly individuals as those aged 60 years and older. In Lithuania, people aged 60 and above accounted for 20.4% of the population in 2006, and this number continues to grow, along with the prevalence of chronic and oncological diseases and the number of individuals requiring long-term care.

Care for elderly patients is primarily provided by family physicians and nurses, who are often the first to assess their needs. Patients who are unable to walk should receive home visits at least once a year. However, diagnosing infections early in such patients is often challenging. A new test, the “TENA U-test,” has recently been introduced in Lithuania. It allows the detection of urinary tract infections (UTIs) in patients using absorbent products, without the need for catheterization.

Changes in the Urinary System With Aging

Aging is associated with structural and functional changes in the kidneys. Connective tissue gradually accumulates, leading to age-related atrophy. These changes include a reduction in kidney size and weight, thinning of the cortical layer, and decreased elasticity of the renal capsule. Such alterations are often more pronounced in men.

The number of functioning nephrons decreases progressively with age—by approximately 10% per decade after the age of 40. As a result, glomerular filtration declines, renal blood flow is reduced, and the kidneys become less efficient at concentrating urine and producing hormones. These changes increase susceptibility to infections, including recurrent UTIs.

Pyelonephritis

Elderly men are approximately twice as likely to develop pyelonephritis as women, largely due to urinary outflow obstruction caused by prostate enlargement. In older patients, pyelonephritis is often bilateral and may present with purulent inflammation.

Acute pyelonephritis is characterized by flank pain, fever, dysuria, frequent urination, and sometimes urinary incontinence. However, similar symptoms may occur in non-infectious conditions such as kidney stones or renal infarction.

Recurrent infections may be caused by persistent bacteria in the urinary tract or reinfection with new pathogens. Chronic pyelonephritis is associated with long-term structural damage to the kidneys, although similar changes may also result from other conditions such as chronic obstruction or metabolic disorders.

Etiology of UTIs

The most common causative agents of acute UTIs include:

• Escherichia coli – the most common pathogen;
• Staphylococcus saprophyticus – more common in women.

Less common pathogens include:

• Enterobacter;
• Enterococcus;
• Klebsiella;
• Proteus mirabilis.

Rare causes include:

• Pseudomonas aeruginosa.

E. coli is responsible for the majority of uncomplicated UTIs, particularly cystitis. These bacteria possess adhesion factors that allow them to attach to the urinary tract epithelium and resist host defenses.

Other pathogens, including fungi such as Candida albicans, are more common in patients with catheter use or those undergoing antibiotic therapy.

Challenges in Diagnosis

Elderly patients often suffer from multiple comorbidities, including urinary incontinence, which complicates diagnosis. Collecting a clean urine sample is frequently difficult in patients who are immobile, cognitively impaired, or unable to cooperate.

Traditional diagnostic methods require proper urine sampling to avoid contamination. In many cases, catheterization is used as a last resort, but it may cause discomfort and increase the risk of infection.

Innovative Diagnostic Solution: TENA U-test

The “TENA U-test” is an innovative tool designed to detect UTIs in patients with urinary incontinence. It is particularly useful when obtaining a urine sample is difficult.

The test is placed inside an absorbent product (such as a diaper), where it collects and analyzes urine. It contains a test card with indicators that detect nitrites and leukocytes based on color changes.

• A green indicator means the test is invalid (insufficient urine).
• An orange indicator confirms the test is valid.
• A color change for nitrites (white to pink) indicates bacterial presence.
• A color change for leukocytes (white to violet) suggests inflammation and infection.

The presence of nitrites or leukocytes indicates a possible UTI, while both positive results suggest a high probability of infection.

The test has high diagnostic accuracy, with sensitivity reaching 96.7% for leukocytes and 90% for nitrites.

Care for Elderly Patients

Managing elderly patients with urinary incontinence requires not only medical treatment but also appropriate care strategies. Absorbent products help maintain hygiene, reduce discomfort, and support social activity, although they do not replace proper treatment.

Maintaining cleanliness, proper hygiene, and monitoring symptoms are essential in preventing complications.

Summary

Urinary tract infections in the elderly are common and often difficult to diagnose due to non-specific symptoms and comorbidities. Accurate diagnosis is essential to ensure appropriate treatment and to avoid unnecessary antibiotic use.

New diagnostic tools, such as the TENA U-test, offer practical solutions for detecting infections in patients where traditional methods are not feasible.

Prepared by Dr. R. Nutautienė
“Lietuvos gydytojo žurnalas”, No. 8