Urinary tract infections

Urinary tract infections (IMCs) are characterized by the presence of microorganisms (most often gram-negative bacteria) in the uropoietic system (in the excretory urinary tract, or in the renal parenchyma or prostate ).

IMC

 * acute x chronic ;
 * asymptomatic x symptomatic ;
 * upper (pyelonephritis) x lower (urethritis, cystitis, prostatitis);
 * pyelonephritis - acute or chronic inflammation of the renal interstitium;
 * urethritis, cystitis - superficial inflammation of the mucous membranes of the urinary tract;
 * uncomplicated x complicated (+ other pathology of the urinary tract - stones, vesicoureteral reflux , or associated disease diabetes mellitus , immunodeficiency ).

Epidemiology
Urinary tract infections are among the most common infections in children - the prevalence is about 1-2%. It affects both sexes, in boys it is more common only in the neonatal period, in school age the ratio of girls: boys is 10: 1, in men the prevalence increases after the age of 40 due to prostatic hyperplasia and urolithiasis. Recurrences are typical for IMC.

Etiopathogenesis
The infection is most often caused by Gram-bacteria, mainly E. coli, less often Proteus mirabilis , Klebsiella pneumoniae , Enterobacter , Pseudomonas ; G + bacteria - Genus Enterococcus and Staphylococcus saprophyticus. Some E. coli tend to adhere to epithelial cells by fimbriae and therefore cause infection more frequently.

The infection most often arises ascendantly (in women mainly due to the short urethra) - from the large intestine through the perineum to the urethra. IMC begins in women by colonizing the vaginal vestibule, in men by the foreskin sac, and then becomes infected with the urethra, bladder, and rarely the upper urinary tract.

Hematogenous infections are rare, but may occur in neonates, the chronically ill, and immunosuppressed patients. Oral and barrier topical contraceptives increase the risk of IMC. Recurrent IMC in adolescents may indicate sexually transmitted diseases (STDs).

, Risk factors for urinary tract infections include: glycosuria in diabetes, for example bladder emptying disorders (urethral stricture, vesicoureteral reflux, bladder post-traction residue and prostate hypertrophy ), as well as stones and pregnancy. Other risk factors are instrumental examinations and the urethra.

Clinical picture
The course differs depending on whether it is acute cystitis or pyelonephritis:


 * acute cystitis - increasing pain during micturition / domestication (terminal dysuria); palpation sensitivity in the lower abdomen;
 * acute pyelonephritis - dull pain in the lumbar region with fever and chills; pain when the kidneys are deeply palpated and when the lumbar region is tapped.
 * Infants and toddlers may occur jaundice or even sepsis You need to ask about specific symptoms, such as an unusual urine odor and diaper blemishes.
 * are often present in older children Dysuria (difficult and unpleasant), polakisuria (frequent urination), stranguria urination), abdominal or back pain, enuresis.

Diagnosis
Laboratory examination:


 * chemical examination of urine and urinary sediment (in fresh urine obtained from the middle stream after washing the genitals with clean water, in women optimally catheterized urine);
 * Urine pH ≥ 6 supports suspected IMC;
 * proteinuria only in pyelonephritis, is small (up to 2 g / 24 h);
 * leukocyturia (evidenced by indication papers, more precisely by examination of urinary sediment - positive finding: more than 10 leukocytes per field of view)
 * the most reliable evidence of leukocyturia and erythrocyturia is quantitative urinary sediment from a three-hour urine collection ( according to Hamburger ) (standard: up to 4000 leukocytes and up to 2000 erythrocytes per minute);
 * quantitative bacteriological examination of urine (always performed if IMC is suspected) - positive finding: 10 5 colonies / ml of urine (but in case of clinical signs we judge IMC with a lower number of bacteria, in children even with 10 3 colonies / ml);
 * asymptomatic bacteriuria - persistent significant bacteriuria without any other symptoms and findings - is often a manifestation of urinary tract damage (anatomical anomalies, stones) in men and children; treatment only in pregnant, immunosuppressed and preoperative (not only urological)
 * urethral syndrome = recurrent polakisuria and dysuria in young women, usually with a negative or quantitatively low bacteriological finding and without leukocyturia; more detailed examination may reveal less common or sexually transmitted flora ( Chlamydia trachomatis, Herpes simplex ); problems are often linked to sexual intercourse (honey-moon cystitis) and usually disappear spontaneously after a few days.


 * The condition for diagnosis is significant bacteriuria (above 10 5 / ml), it is usually accompanied by pyuria, proteiuria , event. and hematuria ;
 * a finding from urine alone is not sufficient for diagnosis - in girls with vaginal influx, urine flows into the vagina and locally irritates, we can find a similar finding.


 * It is always necessary to distinguish total benign cystitis from prognostically more severe pyelonephritis;
 * orientation according to the so-called Jodal criteria - in pyelonephritis the temperature is above 38.5 ° C, sedimentation above 25 mm / h, leukocytosis and increased CRP ;
 * pyelonephritis is also likely with proven vesicoureteral reflux ;
 * in viral cystitis (adenoviruses) - pyuria, macrohematuria and negative bacteriuria;
 * in chronic cystitis - often bacteriuria without pyuria.

Imaging methods:


 * first choice method: kidney ultrasound - we always perform a complicated IMC;
 * renal parenchyma structure, kidney size, pelvis, calyx, ureter width and bladder wall strength;
 * congenital malformations of the urinary tract ; the size of the post-micturition residue when a bladder evacuation disorder is suspected;
 * diagnosis of complications: acute focal pyelonephritis, abscess;
 * event. MCUG - to detect vesicoureteral reflux (VUR) and to assess urethral shape;  sterile primary VUR tends to spontaneously improve and does not lead to scarring of the kidneys, so there is no need for treatment, therefore the examination is performed only in indicated cases;  radiation exposure;
 * static scintigraphy of the kidneys (dimercaptosuccinate 99mTcDMSA) - to assess the function of the renal parenchyma and lateral function of the kidneys; in indicated cases 6 months after infection to assess possible renal scarring, ie. chronic kidney damage; exposure to ionizing radiation.

Treatment
The aim of treatment is to suppress inflammation, prevent recurrences, ev. elimination of the cause (resolution of obstruction, extraction of cystolithiasis, etc.). is essential Early initiation of antimicrobial therapy. Resting regime, adequate fluid intake (2.5 l / 24 h), regular micturition and defecation are regimen measures that are recommended as part of treatment. Antipyretic therapy as needed ( ibuprofen, paracetamol ).

For cystitis, we choose chemotherapeutics that reach high concentrations in the urine, such as oral nitrofurantoin, trimethoprim, cotrimoxazole.

Duration of treatment:


 * uncomplicated cystitis 3-7 days;
 * uncomplicated non-recurrent cystitis and urethral syndrome in women - three days of treatment is sufficient;
 * recurrent cystitis and in men - 7 to 10 days;
 * complicated cystitis - 10 to 14 days and after disappearance we prevent recurrence with one dose of the drug per night for weeks to months.

In pyelonephritis, we choose substances with a high concentration in the blood. If pyelonephritis is suspected, treatment should be started immediately; any delay increases the likelihood of scarring. The choice of antibiotic depends on the regional prevalence of pathogen resistance. In uncomplicated pyelonephritis, we empirically administer potentiated aminopenicillins and cephalosporins of the 2nd or 3rd generation. . With adequate treatment, the clinical condition should improve within 24-48 hours. We adjust antibiotic therapy according to urine cultivation and sensitivity. There was no difference between oral and intravenous treatment (in children from about 2-3 months). Indications for IV ATB are structural congenital defects of the urinary tract, intolerance after ATB or fluid intolerance, severe or septic course of infection. The recommended duration of antibiotic treatment in children is 10-14 days.


 * Supportive therapy: cranberry extracts have a beneficial effect on recurrent IMC (competitive inhibition of bacterial body adherence to the uroepithelium), probiotics (lactobacilli colonize the outer orifice of the urethra and expel gram-negative flora), immunotherapy with application of extracts of bacterial bodies of IMC agents.


 * should be monitored daily at home diuresis, blood pressure should be measured, urine should be collected for quantitative bacteriuria, and the chemical composition of urine should be checked with test papers.


 * Spa care - is a long-term subject of disputes;
 * it must be associated with the drinking of mineral waters, with the establishment of a certain regime of regular fluid intake and emptying.

Prognosis

 * serious late effects are rare (it is quite common and is thought of);
 * uncomplicated lower IMC tends to recur, but does not endanger the patient with renal failure;
 * complicated IMC tends to cause acute pyelonephritis and renal function decreases due to infection and underlying disease (urinary incontinence);
 * main late damage - scars, these most often occur at the age of 3-4 years;
 * the scarred kidney carries a risk of recurrence of infection, hypertension, renal dysfunction;
 * A clearly risk factor for scarring is vesicoureteral reflux, but also hydronephrosis, urolithiasis , nephrocalcinosis etc.

Cystitis

 * most often young women (often related to sexual intercourse), old men (permanent catheterization of the bladder);
 * KO: dysuria escalating at home, polakisuria, palpable pain over the labia;
 * DG: clinical picture, quantitative bacteriuria, urine + sediment;
 * in urine leukocytes, bacteria and sometimes erythrocytes;
 * severe cystitis may be accompanied by macroscopic hematuria.

Acute

 * KO: dull pain in the lumbar region, fever, constipation, severe forms under the image of urosepsis;
 * DG: FW, KO, CRP, S-creatinine (serum creatinine levels are increased), urine, ultrasound;
 * Renal ultrasound to rule out blockage of urine outflow and abscess in the kidney.
 * Jodal's diagnostic criteria :
 * significant bacteriuria;
 * TT >  38 °C ;
 * FW >  30 mm/h ;
 * CRP> 20 mg / l ;
 * needed for diagnosis 3 criteria, bacteriuria always.

Chronic pyelonephritis (chronic

 * sonographic resp. X-ray diagnosis of deformed hollow system and scars of renal parenchyma;
 * it is most often the result of unrecognized vesicoureteral reflux in childhood;
 * also as a result of abuse of analgesic mixtures;
 * KO: often asymptomatic and is diagnosed in late age as the cause of hypertension and decreased renal function ;
 * DG: physical findings are not diagnostic, urinary findings tend to be poor;
 * proteinurie do 1 g/24 h a leukocyturie;
 * in the late course of chronic interstitial nephritis, blood pressure and proteinuria increase, signaling accelerating progression.

Related articles

 * Acute pyelonephritis (pediatrics)
 * Urine examination
 * Examination of the child's uropoietic system
 * Urinary tract infections / case report
 * Purulent pyelonephritis with papillary necrosis (preparation)