Urinary tract infections

Urinary tract infections are infectious inflammations in the area of the urinary tract. They are mainly caused by bacteria, especially intestinal bacteria. The parts of the urinary tract that can be affected include the ureter (connection between the kidney and the urinary bladder), the urinary bladder, and the urethra (connection between the urinary bladder and the genitals). Non-infectious causes of inflammation of the urinary tract are also possible.

Women are far more frequently affected by a urinary tract infection than men. The decisive factor for this is the shorter urethra in women, through which bacteria can reach the urinary bladder much more easily. Approximately every 10th woman suffers from a bladder infection at least once a year. In men, urinary tract infections occur much less frequently, but the frequency increases with age and is often associated with prostate enlargement.

Classification

Basically, urinary tract infections can be differentiated based on their location:

• Lower urinary tract infection:
  The infection is located in the urethra or urinary bladder area. Technically, urinary bladder infection is called cystitis and urethritis. Urethritis alone is usually treated as a separate condition.
• Upper urinary tract infection:
  Sometimes an ascending infection occurs so that the ureter and renal pelvis are also affected. Infectious ureteritis is technically known as ureteritis and renal pelvic inflammation is known as pyelonephritis.

Less common forms of ureteritis are:

• Radiation cystitis:
  This urinary bladder infection is caused by radiation (for example, radiation therapy for cancer).
• Interstitial cystitis:
  This is a chronic bladder infection that is not triggered by an infection with pathogens. The cause is still largely unknown.

Acute urinary tract infections are most frequently caused by intestinal bacteria that enter the draining urinary tract through the opening of the urethra. Approximately 80 percent of all urinary tract infections are caused by the bacterium Escherichia coli (E. coli for short). Other possible pathogens are Proteus mirabilis, Staphylococcus saprophyticus,Klebsiella pneumoniae, Staphylococcus aureus and enterococci. Other pathogens are rare.

For women , past urinary tract infections and sexual intercourse are the greatest risk factors. Frequent sexual intercourse irritates the urethra and makes it easier for bacteria to enter the urinary tract. A urinary tract infection in very sexually active women is colloquially known as "honeymoon cystitis" ("honeymoon cystitis"). The risk of infection also increases during pregnancy, as altered hormone levels promote the development of infections. Similarly, a deficiency of estrogens, which is particularly common after menopause, promotes pathological germ growth and decreases germ resistance.

For men , the greatest risk factor for urinary tract infections is prostatic hyperplasia (enlargement of the prostate).

For women and men, the following factors may pose a risk:

• Urinary obstruction as a result of urinary stones, urethral strictures or growths.
• Advanced age
• Metabolic diseases, e.g. diabetes mellitus or hyperuricemia or gout
• Medical interventions in the urinary tract, e.g. insertion of a urinary catheter or bladder endoscopies
• Immunodeficiency in newborns and infants as a result of chronic diseases or medications (e.g., glucocorticoids)
• Particularly frequent sexual intercourse or special sexual practices (such as anal intercourse without using a condom)
• Hypothermia

Urinary tract infections often develop as a result of incorrectly performed hygiene measures. Girls and women in particular should always take care to dry themselves from the vagina to the anus. When drying in the opposite direction, intestinal bacteria can easily be carried to the urethra.

Only rarely do the pathogens primarily enter the urinary tract via the blood as part of a systemic infection (hematogenous urinary tract infection).

A urinary tract infection involving the urinary bladder (cystitis) usually causes the following symptoms:

• Dysuria: difficulty urinating.
• Alguria: pain when urinating
• Pollakisuria: frequent urination in small amounts
• nocturia: urge to urinate atnight
• Bladder tenesmus: Urinary bladder spasms
• Hematuria: visible (macrohematuria) or invisible (microhematuria) blood in the urine
• Pyuria: visible pus in the urine
• Pain in the area of the lower abdomen

If the germs spread from the urinary bladder via the ureters to the kidneys, an inflammation of the renal pelvis (pyelonephritis) can occur. This is manifested by high fever, a strong feeling of illness and severe pain in the kidney area.

The description of the clinical picture in a medical history usually already suggests a urinary tract infection. To confirm the diagnosis, a urinalysis is performed in which the urine is examined for bacteria, nitrite (only detectable in the urine in the case of bacterial infection of the urinary tract), white and red blood cells.

To ensure that the result is not falsified by bacteria from the outside of the urethra, the urine sample should contain midstream urine. This means that when urine is sampled, the first stream of urine is discarded before the remaining urine is collected in a sterile container.

In addition to urine testing using test strips, the bacteria that cause the infection can be more accurately determined using a urine culture.

Depending on the affected person and their previous illnesses, further clarification with the help of an ultrasound examination or endoscopy of the urinary bladder (cystoscopy) may be useful. Specifically complicating factors such as anatomical or functional limitations should be excluded.

The therapy of an acute urinary tract infection depends largely on the person affected and the localization (cystitis or pyelonephritis) of the infection. Important personal factors are gender, pregnancy, pre- or post-menopausal condition and previous illnesses.

Uncomplicated cystitis in young women heals spontaneously within a week in about 30% to 50% of cases, so that therapy with an antibiotic is not always necessary. To relieve discomfort, antispasmodic or analgesic medications, such as acetaminophen or ibuprofen, can help. Drinking enough water and keeping warm can also help symptoms to subside.

As a rule, however, treatment with antibiotics is the primary treatment, especially in the case of complicated and recurring urinary tract infections. Active substances used for this purpose include:

• Pivmecillinam
• Trimethoprim-sulfamethoxazole
• Fosfomycin
• Nitrofurantoin

The antibiotics have a rapid effect on acute bladder infections and accelerate the healing of the inflammation.

Antibiotics are also administered for upper urinary tract infections (e.g. inflammation of the renal pelvis). In this case, therapy is often started with broad-spectrum antibiotics. Treatment by infusion via the vein (intravenous antibiosis) may also be indicated. In severe or prolonged cases, the pathogen should be detected by means of bacterial cultures and the therapy should be continued with a suitable preparation according to the antibiotic resistance.

Permanent, preventive use of a specific antibiotic may be useful, in consultation with a physician or urologist, especially in women with recurrent urinary tract infections. Other medications and supplements can also be used to reduce the frequency of urinary tract infections. Described active substances in this regard include L-methionine, lactobacilli, mannose, hydroquinone and cranberry juice. The scientific data on the substances are not clear and the effect is not always proven with certainty.

With proper treatment, a urinary tract infection usually heals after a few days. Women in particular are at higher risk of suffering from recurrent urinary tract infections. However, these are usually also easily treatable.

If, in addition to the lower urinary tract infection, there are any conditions such as a urinary outflow obstruction (e.g. due to an enlarged prostate) or malformations of the ureters, these pose an additional risk of the infection ascending to the upper urinary tract and thus causing a renal pelvic inflammation. It is therefore recommended that these risk factors be treated.

If a urinary tract infection is not treated appropriately, it can spread further and enter the bloodstream (urosepsis). This can lead to a life-threatening illness.

To prevent a urinary tract infection, the following measures may be helpful:

• Ensureadequate fluid intake:
  It is recommended to drink at least 1.5 to 2 liters of fluid daily, such as water or unsweetened teas, in order to flush the draining urinary tract well. In addition, special bladder and kidney teas can be drunk, which can stimulate the kidneys to increase urine production due to their contained plant extracts such as birch, nettle, juniper or horsetail.
• Do not let the feet as well as the abdomen cool down:
  Wet clothes and bathing suits should be taken off immediately if possible.
• Intimate hygiene:
  Here, it is recommended to avoid excessive use of douches and intimate lotions.
• Bearberry leaf tea:
  The active ingredient hydroquinone contained in it has a disinfecting effect on the urine and can thus reduce the risk of urinary tract infections.
• Cranberries:
  The berries contain many tannins (tannins), the action of which makes it difficult for bacteria to attach to the inner wall of the urinary bladder or tract. The cranberry preparations are available as capsules, tea or juice.