Urinary tract infections in elderly people
The world's population is constantly aging. It is projected that by 2025, the percentage of elderly people in Europe will increase from 20 to 28 percent. Demographers consider individuals aged 60 and older as elderly. In Lithuania, people aged 60 and older accounted for 20.4 percent of the total population in 2006, and this number is growing, along with an increase in chronic, oncological diseases, and the number of patients requiring care. Currently, the assistance for elderly people is mainly provided by nurses and family doctors. They are the first to visit the elderly person and assess their needs. Elderly individuals who are unable to walk should be visited at least once a year at home. However, it is difficult to examine them and accurately diagnose early infections. A new test called "TENA U-test" has appeared in the Lithuanian market, capable of identifying urinary tract infections (UTIs) in patients wearing diapers without catheterization.
Changes in the Urinary System with Aging
As a person ages, connective tissue accumulates in all structural elements of the aging kidney, leading to senile organ atrophy. The morphological changes in kidney structure do not always correspond to typical nephrosclerosis. Connective tissue accumulates unevenly in various kidney areas, resulting in a variety of changes. The main sign of senile kidney atrophy is a decrease in organ weight and size, along with thinning of the cortical layer. These changes are more pronounced in men. With aging, the kidney capsule thickens and hardens, the paranephric fibroblasts increase, and the renal sinus scleroses. Due to these changes, kidney amortization deteriorates, leading to impaired urine drainage, kidney blood flow, often resulting in retention cysts in the kidneys, and the organ surface becomes rough. The kidney nephron, the main structural and functional unit of the kidneys, typically begins to age around the fifth decade of life. Every decade after the age of 40, the number of well-functioning nephrons decreases by 10 percent. The aging process of kidney nephrons usually starts with the glomeruli. Due to these and other involutional changes, glomerular filtration deteriorates. Therefore, as a person ages, the kidneys also age: renal arteriosclerosis progresses, glomerular and tubular hyalinosis, interstitial tissue sclerosis occur, renal vascular resistance increases, concentration and hormone production function are disrupted, urine excretion decreases, resistance to infection decreases, leading to recurrent UTIs.
Pyelonephritis
Elderly men are twice as likely to suffer from pyelonephritis as women. Urinary drainage disorders have a significant impact on pyelonephritis in older people. Since many elderly men suffer from prostate adenoma, which causes urinary retention, men are more likely to develop pyelonephritis. Senile pyelonephritis is usually purulent and often affects both kidneys. Acute pyelonephritis is a clinical symptom characterized by flank pain, fever, painful and frequent urination, urinary incontinence. These symptoms can also occur without infection, for example, in cases of kidney infarction or kidney stones. A more precise description of acute pyelonephritis is a syndrome accompanied by symptoms of symptomatic bacteriuria and acute infection. UTIs can be primary or recurrent. Recurrent bacteriuria refers to pathogens present before starting treatment. It is caused by the persistence of microorganisms in the urinary tract. A new infection involves microorganisms different from those present previously. Sometimes, a new infection can be caused by microorganisms from the vagina and rectum. Chronic pyelonephritis, according to some authors, is associated with pathological changes due to kidney infection. However, similar changes in the kidneys can also occur with chronic urinary tract obstruction, analgesic, hypokalemic, uric acid nephropathy.
UTI Etiology
More common causative agents of acute STIs:
. E. coli – most common;
. S. saprophyticus – in women.
Less common causative agents of STIs:
. Enterobacter;
. Enterococcus;
. Klebsiella;
. Proteus mirabilis.
Very rare:
. Pseudamonas aeruginosa.
E. coli most commonly causes uncomplicated STIs in women:
cystitis (90%), pyelonephritis, often asymptomatic. Uropathogenic
E. coli has adhesive proteins for urinary tract epithelial cells, produces hemolysins, and is resistant to bactericidal serum effects. The infection usually enters the urinary tract from the perineum. Microorganisms of the Corynebacterium group more commonly cause nosocomial rather than acute STIs. These gram-negative rods cause acute and chronic cystitis, pyelonephritis, are often resistant to antibiotics, sensitive only to vancomycin. Anaerobes are rare uropathogens. Fungi, especially Candida albicans, and other species are found if catheters were used, undergoing antimicrobial therapy. Staphylococcus saprophyticus causes infection in young women, especially sexually active ones – they are the causative agents of acute cystitis. They enter the kidneys through the blood and cause renal or peripheral abscesses.
Challenges in STI Diagnosis
Elderly individuals suffer from numerous diseases. One of them is urinary incontinence, which in terms of prevalence and costs surpasses many serious diseases. For example, in Germany, the annual treatment costs of urinary incontinence are equivalent to dementia, diabetes, or other chronic diseases combined. Therefore, urinary incontinence is a health disorder that causes medical, social, and hygiene problems. For some patients, especially those with other chronic illnesses, disabilities, the only possible solution is to deal with the consequences of urinary incontinence by planning quality care and using products that absorb and retain urine. These can help patients remain socially active but do not replace complete treatment. Special urine-absorbing products help save money and time in caring for a patient who cannot retain urine, reduce discomfort and emotional tension for caregivers. STI symptoms need to be confirmed or ruled out. Traditionally, this is done by taking a patient's urine sample and performing a biochemical urine test strip. The urine sample must be taken properly to avoid contamination. It is often difficult to obtain urine samples from patients who have urinary incontinence, are disabled, have mobility issues, or cannot cooperate. Ensuring that the sample is clean and suitable is also not easy. Catheterization is the last resort as it causes pain and discomfort and can also promote STIs.
Assistance for Elderly, Care-Dependent Individuals
“TENA U-test” test is an innovative tool for STI detection. It is designed for patients with urinary incontinence who suffer from STI symptoms. The test is placed in clean diapers – it collects and analyzes urine. The examination is performed while the product is in the diaper. “TENA U-test” is developed for patients with urinary incontinence. It is useful when it is difficult to obtain a urine sample using traditional methods, when the patient has difficulty communicating, is disabled, bedridden, or suffers from dementia. The “TENA U-test” can be used without disturbing severely ill individuals. The test consists of a test card that is attached to the urine-absorbing product. The test card has a reaction window with dry chemical indicators that detect nitrites and leukocytes (indicated by the color change of the reaction). The third indicator changes color when enough urine enters the reaction window. Once enough urine is collected, the indicator's color changes from green to orange, indicating the presence of nitrite indicators.- from white to pink, and leukocytes - from white to violet, if these substances are present in the urine (see picture). The presence of nitrites or leukocytes in the urine indicates a possible STI. The test indirectly detects the presence of bacteria that convert nitrates in the urine into nitrites, therefore the indicator changes color from white to pink. The presence of leukocytes is indicated by a color change to violet in the indicator field. Leukocytes are a sign of an existing infection. Possible test results:
. green - test invalid (insufficient amount of urine in the reaction cell);
. orange - test valid (sufficient amount of urine in the reaction cell; test performed correctly and can be evaluated);
. nitrites and leukocytes negative - no signs of STI;
. nitrites positive, leukocytes negative - signs of STI;
. nitrites negative, leukocytes positive - signs of STI;
. nitrites and leukocytes positive - high probability of STI.
The test strips contain color indicators (methyl red, bromophenol blue) and dye components (tetrahydro-benzo-quinoline, sulfanilic acid, carboxylic acid esters, diazonium salts).
In the presence of leukocytes, the test shows a positive result in 96.7% of cases, in the presence of nitrites - 90%. In the absence of leukocytes, the test shows a negative result in 100% of cases, nitrites - 98.3%.
Summary
Urinary tract infections are treated with various types of antibiotics. The duration of treatment and the type of antibiotics depend on the overall condition of the patient and the type of bacteria found in the urine. A correct STI diagnosis guarantees proper treatment and protects against more serious illnesses. However, based on nonspecific clinical signs and symptoms, STIs are diagnosed and treated too often, leading to unnecessary antibiotic prescriptions for patients.
Prepared by Dr. R. Nutautienė
"Lietuvos gydytojo žurnalas" No.8
