Epidemiology of urinary tract diseases in general practice

During a one-year morbidity survey of urinary tract diseases in general practice 741 cases were diagnosed. Only about half of all the patients with symptoms of urinary tract infection had significant bacteriuria. In young women urinary tract infections and symptoms from the urinary tract without bacteriuria—in particular urethritis—were found to predominate. In middle-aged women, the urinary tract symptoms were ascribed increasingly to genital prolapse, while incidence of urolithiasis was the highest in any group, and urinary tract infections became less frequent. The prevalence of urinary tract infection showed another increase in elderly women, and recurrent/chronic pyelonephritis, which occurs with a steadily increasing prevalence throughout all age groups, became common.In younger male urological patients diseases with symptoms of urinary tract infection without bacteriuria were predominant, whereas prostatitis and urinary tract infections were less frequent. In middle-aged men, urolithiasis was especially frequent, while an increasing proportion of elderly men had prostatic hypertrophy, urinary tract infections, and recurrent/chronic pyelonephritis.     

Characterization of adhesion associated surface properties of uropathogenicEscherichia coli

Escherichia coli was isolated from the urine of patients with pyelonephritis, with urinary tract infections other than pyelonephritis and with asymptomatic bacteriuria. Surface properties of the strains were analyzed by the salting-out aggregation test (SAT), hydrophobic interaction chromatography (HIC), Congo red binding (Crb), agglutination of erythrocytes (MRHA) and latex particles covered by digalactoside (PF) and by adherence to tissue culture cells. In addition, a DNA probe for thepap gene was used. The DNA probe detected the highest proportion of strains withpap gene in the group of patients with pyelonephritis, lower in the urinary tract infections other than pyelonephritis and the lowest in the group with asymptomatic bacteriuria. Tests for P-fimbriae (PF, MRHA) showed a similar distribution. Hydrophobicity measured by SAT and by HIC did not show differences among the tested groups of strains. The results suggest that factors other than the P-fimbriae and hydrophobicity may contribute to the persistence ofE. coli in the urinary tract.     

Pregnancies in women with and without renal scarring after urinary infections in childhood.

OBJECTIVE--To compare the outcome of pregnancy in women with and without renal scarring after childhood urinary infections with that in unmatched controls. DESIGN--Retrospective study of pregnancies in women prospectively followed up from their first recognised urinary infection. SETTING--Tertiary referral centre in Gothenburg. SUBJECTS--111 Women attending an outpatient clinic for women with urinary infection during 1975-83, of whom 41 (65 pregnancies) were studied (19 women with renal scarring (32), 22 without scarring (33)), and 65 controls (65) randomly selected and matched for parity, age, smoking habits, and date of delivery. MAIN OUTCOME MEASURES--Urinary infections and complications in pregnancy. RESULTS--The incidence of bacteriuria during first pregnancies was significantly greater in women with (9, 47%) and without (6, 27%) renal scarring after childhood urinary infection than in controls (1, 2%) (p less than 0.001, 0.01 respectively). Symptomatic infections were seen only among women with a history of urinary infection: four women with renal scarring (three of whom had vesicoureteric reflux) developed pyelonephritis and three cystitis, and one woman without scarring developed pyelonephritis. Mean blood pressure was higher among women with severe renal scarring than controls (4/11 v 3/44; p less than 0.05) before and during pregnancy. There was no significant difference in the incidence of pre-eclampsia, operative delivery, prematurity, or birth weight. CONCLUSIONS--Women with a history of previous urinary infections had a high incidence of bacteriuria during pregnancy, and those with renal scarring and persistent reflux were prone to develop acute pyelonephritis. The risk of serious complications in pregnancy, however, was not increased in women with severe renal scarring, possibly owing to their continuous clinical supervision.     

The role of Tamm-Horsfall protein in the pathogenesis of reflux nephropathy and chronic pyelonephritis

Recurrent bacterial infection of the kidney was previously thought to be responsible for the renal scarring typical of chronic pyelonephritis until recent studies suggested that recurrent bacteriuria rarely produces chronic pyelonephritis in the absence of obstructive uropathy. In contrast, the association between vesicoureteral reflux (VUR) and chronic pyelonephritis has been observed frequently in the absence of urinary infection. Although the mechanism by which VUR injures the kidney has not been defined, recent observations have suggested that some component of urine might serve as an antigenic determinant involved in the immunopathogenesis of renal scarring in VUR. Therefore, the present studies investigated the immunopathogenic role of Tamm-Horsfall protein (THP) in (1) a rabbit model of tubulointerstitial nephritis; (2) a swine model of reflux nephropathy; and (3) patients with recurrent nephrolithiasis. The antigenic similarities between THP and uropathic bacteria were also studied. Our observations indicate that autoimmune responses to THP may occur after exposure to THP by intravenous challenge in rabbits, by urinary reflux in pigs, and in recurrent nephrolithiasis in man. Also, extracts of uropathic coliforms competitively inhibit the binding of human THP to its antibody. These studies suggest that autoimmune responses to THP may be the pathogenetic mechanism by which these factors, including bacteriuria, contribute to "chronic pyelonephritis."     

Application of biotinylated and32P probes for detection of P-fimbriae in urinaryE. coli

Escherichia coli is the common causative agent of urinary tract infections. Twenty-six strains ofEscherichia coli were isolated from children with pyelonephritis, symptomatic urinary tract infections and asymptomatic bacteriuria. Biotinylated and³²P-DNA probes were prepared for detection of P-fimbriae in the isolates. Of the 13 strains isolated from patients with pyelonephritis 11 were positive for the presence of the P gene by both probes. Strains isolated from cases of symptomatic urinary tract infections revealed the presence of P gene only in three samples of the total of nine isolated. None of the isolatedE. coli strains from asymptomatic bacteriuria was found positive for the presence of the P gene. The biotynylated probe was simple and easily applicable in standard laboratory conditions and therefore the authors recommend it for use in diagnostic laboratories.     

Untreated asymptomatic bacteriuria in girls: II--Effect of phenoxymethylpenicillin and erythromycin given for intercurrent infections.

OBJECTIVE--To investigate the effects of phenoxymethylpenicillin and erythromycin on urinary isolates from patients with untreated asymptomatic bacteriuria. DESIGN--Retrospective study of subgroup of patients from cohort followed up till the end of 1986. SETTING--Outpatient clinic for children with urinary tract infections. PATIENTS--51 Girls aged under 15 with untreated asymptomatic bacteriuria. INTERVENTIONS--Before 1982 intercurrent infections (mostly tonsillitis or otitis) were treated with phenoxymethylpenicillin; after 1982 erythromycin treatment was preferred. END POINTS--Change of bacterial strain in urinary tract and symptomatic recurrences of disease. MEASUREMENTS AND MAIN RESULTS--Bacteria identified by serotype and electrophoretic type and compared before and after antibiotic treatment. Bacteriuria eradicated and replaced by new strains in most patients treated with phenoxymethylpenicillin, leading to symptomatic recurrences in about 15%. Conversely, patients given erythromycin rarely showed change in bacteriuria and none suffered symptomatic recurrence. CONCLUSIONS--In girls with untreated asymptomatic bacteriuria the use of phenoxymethylpenicillin for intercurrent infections may lead to a change of urinary bacteria and leave them at substantial risk of acute pyelonephritis. With erythromycin this risk is small (2/20 courses in this series).     

A study for the improvement of the cytological urine examination performances in upper tract infection diagnosis

Diagnosis of the location of upper and lower urinary tract infection (UTI) is necessary in defining the therapeutic conduct that has a different period and intensity according to the infection location and in prognosis. Many studies show the lack of clinical criteria peculiarity in revealing the different location of UTI. As a result, the correct location of the level in which UTI develops is the necessity of paraclinical investigations. Urinary sample examination, in which urinary sediment microscopy is essential, is a reliable technique in fast detection and localization of UTI. Finding, in pyuria context, the classic significant bacteriuria (> or = 10(5) CFU/ml) or lower value bacteriuria (< or = 10(4) CFU/ml) confirms the UTI diagnosis. The upper tract infection prognosis increases when leukocyte cylinders, characteristic for pyelonephritis, appear together with intact or degraded leukocytes, single or grouped. We settled an algorithm to examine the urine samples in order to: Concentrate and preserve the structural integrity of leukocytes and cylinders, examining the conventional urinary sediment Precisely identify and differentiate these elements by vital coloration (leukocyte peroxidase coloration and Sternheimer - Malbin coloration) to establish more accurate the UTI level. The vital coloration for leukocyte peroxidase has cytological specificity, confirming the pyuria and the cylinders that contain leukocytes (leukocytary, granular, mixed) and obviously ameliorates the reliability and reproducibility of the urinary sediment cytological exam.     

Genetic determinants of Escherichia coli pathogenicity isolated from urine and feces of children with different clinical variants of urinary system infection

In the process of examination of 156 children of different age groups 176 E. coli cultures were isolated; of these, 98 cultures were isolated from acute cystitis and pyelonephritis patients, 28--from urine in cases of aysmptomatic bacteriuria, 30--from feces in cases of asymtomatc bacteriuria and intestinal dysbacteriosis, while 20 cultures--from feces of healthy children. In these bacteria the presence of genes associated with pathogenicity islets (PI) hlyA, hlyB, cnf-1, papC, sfaG and gene irp-2 (iron-regulated protein) was established with PCR. The detection rate of PI determinants in uropathogenic E. coli (UPEC) was shown to depend on the variants of the clinical manifestation of urinary tract infection. The total detection rate of PI gene fragments in UPEC cultures of different origin was indicative of their definitely less frequent occurrence in asymptomatic bacteriuria, observed simultaneously with intestinal dysbacteriosis, in comparison with acute urological infection. Practically the same detection rate of PI determinants in E. coli, isolated in asymptomatic bacteriuria in children, reflected high probability of genetic exchange in the above-mentioned fragments and made it possible to presume the existence of DNA sites, characteristic mainly of pathogenic clones. The established heterogeneity of the detection rate of PI determinants in E. coli clinical isolates requires further study.     

Development of hypertension and uraemia after pyelonephritis in childhood: 27 year follow up.

OBJECTIVE--Determination of the long term incidence of uraemia, hypertension, and toxaemia in pregnancy associated with non-obstructive focal renal scarring after pyelonephritis in childhood 25-35 years earlier. DESIGN--27 Year follow up of patients with non-obstructive focal scarring identified from a retrospective review of intravenous urograms performed in childhood between 1951 and 1967. SETTING--Paediatric primary referral centre and urological clinic in tertiary referral centre. PATIENTS--30 Patients (mean age 33 (range 22-41] with non-obstructive focal renal scarring first detected between 1951 and 1967 and a history of febrile urinary tract infection. MAIN OUTCOME MEASURE--Hypertension and complications of renal damage. RESULTS--Three patients had developed end stage renal disease, seven had developed hypertension, two of 16 women had a history of toxaemia during pregnancy, and seven patients had undergone renal surgery during follow up. Of the 20 patients who had neither had renal surgery nor had end stage renal disease, all had a significantly lower glomerular filtration rate and renal plasma flow and higher diastolic blood pressure, mean arterial blood pressure, plasma renin activity, and serum beta 2 microglobulin concentration than 13 healthy age matched controls. Diastolic blood pressure and plasma renin activity were positively correlated (r = 0.50, p less than 0.05) and so were fractional sodium excretion and both systolic and diastolic blood pressures (r = 0.54, p less than 0.01, r = 0.51, p less than 0.01 respectively). The progress of renal damage was unrelated to the incidence of recurrent infections. CONCLUSIONS--Children with focal renal scarring due to pyelonephritis are at high risk of serious long term consequences. It is essential that they are given adequate attention and care during adolescence and pregnancy.     

The role of E. coli adhesiveness in the pathogenesis and clinical course of urinary tract infections]

An infection with E. coli is the most frequent cause of the urinary infections in childhood. Virulence depends on several factors out of which a principal role is played by the adhesion of bacteria to the urinary tract epithelium. Such a property have E. coli strains with adherence mannose-positive fimbriae of type P with antigens recognizing and binding glycolipid receptors on epithelial cells in the urinary tract. Children with such infections owe their "sensitivity+" (10% of the population) to genetically determined large number o receptors binding E. coli strains. Incidence and clinical course of the urinary tract infections have been analysed in the group of 184 children. Moreover, sequelae of the urinary tract infections with E. coli have been analysed in dependence on E. coli strain characteristics, i.e. presence or absence of adherent fimbriae from cases of cystitis and significant asymptomatic bacteriuria. Considering pathogenesis of the urinary tract infections as the result of interactions between bacteria and host, antigenic properties of adherent fimbriae might be used for preparation of a vaccine preventing such infections.     

A Comparative Study of the Triphenyltetrazolium Chloride (Uroscreen) Test and Conventional Methods for the Detection of Bacteriuria

Acute urinary tract infection may be preceded by and active pyelonephritis may be associated with asymptomatic bacteriuria. Treatment of asymptomatic bacteriuria may prevent or arrest active, chronic pyelonephritis and its sequelae. Consequently, there is a need for a reliable and simple screening procedure to detect asymptomatic bacteriuria in large segments of the population.The reliability and practicability of tests advocated for the detection of bacteriuria, including the new chemical triphenyltetrazolium chloride (T.T.C.) (Uroscreen) test, were evaluated. Reliability was assessed by correlating results of these tests with bacterial counts of tested urines. Significant bacteriuria is defined as the presence of 100,000 or more organisms per ml. of urine.The T.T.C. (Uroscreen) test was positive in 92.5% of cases of bacteriuria; there were 7.5% false-negative and 2.8% false-positive results. Bacteria on Gram-stained smear were found in 95.5% of the cases of bacteriuria and in 14.6% of those with non-infected urine; pyuria (more than three leukocytes per high-power field), in 60% of those with bacteriuria and in 15.9% of those with presumably non-infected urine. Bacteria were conspicuous in the urinary sediment in 91.1% of cases of bacteriuria and in 3.7% of presumably non-infected urines.The T.T.C. (Uroscreen) test fulfilled the criteria for a reliable and simple screening procedure. It should be used concomitantly with other screening tests when the urine is examined routinely.     

Serodiagnosis and the immunological aspects of Proteus infection. IV. Serum antibody level and the pathomorphological and bacteriological indices in experimental mixed and monoinfections of the urinary tract

In developing the serodiagnosis of the Proteus infection of the urinary tract experimental hematogenic Proteus or Proteus-Escherichia pyelonephritis was reproduced. In this infection the time course, level and avidity of serum antibodies correlated with the isolation of the causative agents from urine samples used as seed material and with histological changes in the kidneys. The serological tests revealed high titres of H-antibodies and the presence of O-antibodies, while in cases of bacteriuria not accompanied by kidney lesions only H-antibodies in low titers were detected. The results obtained in the study of immune shifts can be used for etiological diagnosis and more exact localization of the pathological process in the urinary system.     

Pathogenic characteristics of Escherichia coli strains in cases of asymptomatic bacteriuria and symptomatic urinary tract infections

The aim of this study was to examine if E. coli isolated from asymptomatic bacteriuria differed in pathogenic features from strains isolated from symptomatic infections of urinary tract. In this study 130 strains of E. coli isolated from women having asymptomatic bacteriuria and 112 strains isolated from patients with symptoms of urinary tract infection were examined. It was shown that E. coli isolated from patients with symptomatic urinary tract infection showed the more frequently ability to cause mannose-resistant haemagglutination of human erythrocytes, resistance to bactericidal activity of serum and haemolytic properties than those isolated from asymptomatic bacteriuria. These strains showed also the higher ability to adhere to Vero cells in tissue culture. Among E. coli strains isolated from persons with asymptomatic bacteriuria the pathogenic features were most frequently found in strains from healthy women and the most rarely in isolated from diabetic women.     

Influence of P blood group phenotype on susceptibility to urinary tract infection

Bacterial attachment is an important event in the pathogenesis of urinary tract infection (UTI). Increased receptivity on the host cells has been suggested influence proneness to infection. The dual function of the globoseries of glycolipids both as receptors for attaching E. coli and as P blood group antigens lead us to examine the P blood group phenotype distribution in UTI prone patient populations. A correlation between the P1 blood group phenotype and susceptibility to UTI was found. Patients with recurrent pyelonephritis had 74/79 (94%), P1 compared to 75% in healthy controls. In contrast patients with asymptomatic bacteriuria (ABU) had a reduced frequency of P1, 43/74 (58%). P1 and P2 individuals differ in amount and composition of the globoseries of glycolipids on their erythrocytes. A similar difference in other tissues, e.g. uroepithelial cells might explain the association of P1 with UTI. There was, however, no significant difference in bacterial adherence to uroepithelial cells from P1 and P2 individuals. Other mechanisms explaining the increase in P1 individuals in recurrent pyelonephritis are discussed.     

Bacterial urinary infections in acute leukemia

Hundred thirty patients with the acute leukemia were examined. Bacterial urinary infections were detected in 34% of the examined patients, statistically more frequently in women. Decreased response to the inflammatory process is noted in leukemic patients with the urinary infections. Non-stable clinical symptoms, multiple changes in the normal laboratory findings in both the urine and blood serum may suggest urinary infection which should be confirmed by the urinary cultures. The most frequent causes of the urinary infections are various species of gram-negative bacteria of Enterobacteriaceae similarly to non-leukemic patients with urinary infections. Reinfections and superinfections were seen in some patients but the latter were more frequent in the acute lymphoblastic leukemia.     

Three-day and ten-day chemotherapy for urinary tract infections in general practice.

The length of a course of antibiotic treatment for urinary tract infection varies with the habits of the prescriber. Many patients do not complete a course of treatment once their symptoms have subsided. In uncomplicated urinary tract infection among women seen in general practice a three-day course of amoxycillin was as effective as a 10-day course of the same drug in the same dose. Relief of symptoms was equal in both groups and bacteriuria was eliminated equally successfully in both regimens. There was no significant difference between the two groups in the incidence of side effects from the drugs. The financial saving which could accrue from adopting this therapeutic regimen would be significant.     

Untreated asymptomatic bacteriuria in girls: I--Stability of urinary isolates.

OBJECTIVE--To assess the frequency of spontaneous changes of bacterial strains in patients with untreated asymptomatic bacteriuria. DESIGN--Retrospective analysis of samples from all patients with renal scarring and random sample of patients with normal kidneys. SETTING--Outpatient clinic for children with urinary tract infections. PATIENTS--54 Girls aged 3.3-15.5 years with untreated asymptomatic bacteriuria caused by Escherichia coli. INTERVENTION--None. END POINT--Change in bacterial strain. MEASUREMENTS AND RESULTS--Serotyping and electrophoretic analysis of sequential bacterial isolates, representing 151 patient years of untreated asymptomatic bacteriuria. A total of 24 changes of strain were identified. Eleven were related to medical interference such as treatment of other infections with antibiotics. CONCLUSIONS--Spontaneous changes of strain were uncommon, one change in 11.6 patient years, and thus are not a characteristic feature of the course of asymptomatic bacteriuria.     

Cobalt Tumor of the Thyroid Gland

Diminutive kidney, hypoplasia or atrophic pyelonephritis, may be the cause of hypertension, lumbar or abdominal pain, obscure gastrointestinal symptoms or chronic urinary infection accompanied by chills and fever. A hypoplastic kidney is prone to infection and stone formation.Diagnosis includes meticulous x-ray examination and renal function studies employing the more accurate quantitative phenolsulfonphthalein test of each kidney.Nephrectomy is the treatment for unilateral disease causing symptoms; localized atrophic pyelonephritis is amenable to partial resection.Since urinary stasis invites infection, obstructing ureteral strictures should be dilated. Pyelectasis, secondary to ptosis, and ureteropelvic obstruction should be corrected by nephropexy or plastic repair. These conservative measures may prevent renal destruction.Sixteen patients were subjected to nephrectomy: Six because of persistent pain and chronic infection and ten because of hypertension. The six with pain and chronic urinary infection were relieved. In six of the ten with hypertension, the disease recurred within six months to seven years.     

Trial evaluation of familial asymptomatic bacteriuria]

Between September 1, 1987 and December 1, 1988, 57 cases of asymptomatic bacteriuria were distinguished in the group of 2,898 schoolgirls, aged between 15 and 20 years (mean 16.7 years). For screening purposes Griess'test modified by Sleigh was used. Bacteriologic tests have shown, that 12 out 57 mothers (21.05%) and 5 out of 39 sisters (12.82%) suffered from asymptomatic bacteriuria, while this pathology was diagnosed in 61 (2.10%) out of all control population, i.e. 66 girls. Incidence of the asymptomatic bacteriuria was 4.55% in the 66 mothers. The differences in the incidence of the infection between the whole population and mothers of the control group, and between sisters and mothers of girls with asymptomatic bacteriuria were statistically significant (p < .001 and p < .01, respectively). History of the urinary tract infections was significantly more frequent in girls with asymptomatic bacteriuria, their mothers and sisters than in the control group. Type of bacterial strains isolated from the urine, similar sanitary conditions in these families as well as the lack of ultrasonographically and renographically diagnosed urinary pathologies in 11 out of 13 girls whose mothers and sisters suffered from asymptomatic bacteriuria suggest that familial asymptomatic bacteriuria may have a genetic background.     

Urinary Concentrating Ability in Women with Asymptomatic Bacteriuria in Pregnancy

The incidence of impaired renal concentrating ability in pregnant women with asymptomatic significant bacteriuria is significantly less than previously reported when osmolality readings are performed on every urine specimen obtained during the 24 hours'' deprivation of fluids. The concentrating defect is more considerable as pregnancy progresses. The lower the maximum urinary osmolality the more difficult is the treatment of the patient, and the higher the incidence of acute pyelonephritis.