General infectiology
Causes of infections
The multiplication of bacteria (or other, rarer, pathogens) in the urogenital tract can lead to various forms of urinary tract infections. In about 80 - 90 % of cases, the inflammation is caused by ascending germs which enter the urinary tract naturally, i.e. via the urethra. In this case, we speak of ascending urinary tract infections. In most cases, the triggering pathogens are intestinal germs which are carried from the anal and perineal regions. The most common pathogen is the E. coli bacterium.
Acute cystitis is a problem that mainly affects women. The short urethra of female patients assists the penetration of germs into their urogenital tract. The ascension of germs during sexual intercourse and the choice of contraceptive may also play a role. Changes in the hormone balance during and after the menopause can also lead to a weakening of the defence mechanisms due to local oestrogen deficiency. Likewise, the hormone-induced dilatation of the urinary tract during pregnancy can lead to increased urinary tract infections.
Irrespective of gender, there is an increased risk of infection in cases of micturition disorders that give rise to the formation of residual urine, such as can occur in men, particularly where they have difficulty passing water due to benign prostate enlargement (benign prostate hyperplasia) or narrowing of the urethra (urethral stricture). In women, a micturition disorder is often caused by a lowering of the pelvic floor. In rare cases, neurological diseases can also be the cause of incomplete emptying of the bladder. In addition, there is an increased risk of infection when the urinary tract is interfered with, such as in the case of cystoscopies or catheter inserts. Other possible causes include obstruction of the urinary tract through urinary stones or other foreign bodies, disturbances of the immune system, as in the case of diabetes, or a genetic susceptibility to increased "adhesion" of bacteria to the mucous membranes of the urinary tract.
Other infection pathways, such as bacterial colonisation via the bloodstream (haematogenic), the lymphatic system (lymphogenic) or direct bacterial penetration (i.e. migration) of neighbouring organs are rare, but occur for example in patients with urogenital tuberculosis or in connection with renal abscesses. In the case of inflammatory processes, such as chronic inflammatory bowel diseases (ulcerative colitis, Crohn's disease), diverticulitis or gynaecological diseases of the female pelvis (ovarian or fallopian tube inflammation), local germ spread is possible, sometimes with fistula formation.
Symptoms and diagnosis
In addition to the typical symptoms of acute inflammation of the urinary tract, such as a burning sensation when urinating (dysuria), frequent urge to urinate (pollakiuria) and in some cases the presence of blood in the urine (haematuria), the urine is examined for inflammatory cells (leukocytes), red blood cells (erythrocytes) and bacterial decomposition products (nitrite) by means of a rapid test and microscopic urine examination. Usually, the so-called mid-stream urine is examined for this purpose. In certain cases it can be advisable to examine urine extracted from the bladder under sterile conditions by means of a catheter (catheter urine). In addition, a microbiological examination of the urine is carried out; a urine culture is prepared for this purpose. After application of the urine to various culture media, the bacteria are given time to grow in an incubator and after about 48 hours the bacterial count, the type of pathogen and the antibiotics tested as sensitive can be determined.
In the case of more severe inflammation, fever, shivering and a significant reduction in general wellbeing may also occur. Often, pain is then reported in the area of the kidneys or, in men, in the area of the prostate or testicles. For advanced inflammation of this kind, medical treatment is absolutely essential, and the patient should be seen by a urologist or taken to an emergency urological outpatient clinic immediately.
