Episode Of Acute Pyelonephritis Research Articles

Clinical Trial of the Outpatient Management of Pyelonephritis in Pregnancy

Objective: This study was designed to determine whether outpatient treatment of pyelonephritis in pregnancy can reduce costs without compromising safety or efficacy. Methods: Pregnant patients with uncomplicated initial episodes of acute pyelonephritis were considered for outpatient management. The outpatient treatment consisted of an initial dose of IV ceftriaxone (2 g), followed by daily outpatient IM ceftriaxone (2 g) until resolution of fever and flank tenderness, followed by a 10-day course of oral antibiotics. The study group was compared with a group requiring inpatient treatment and a historical control group meeting the criteria for outpatient management but having been treated as inpatients in the previous year. Results: Of the 34 treated as outpatients, only 4 (12%) required hospital admission and 1 developed an upper urinary tract recurrence. None of these patients had premature delivery or any other serious complication. The historical control group (N = 29) included 1 upper urinary tract recurrence, no preterm deliveries, and 1 case of acute respiratory disease syndrome. The outpatient group required an average of 3.4 daily outpatient visits compared with 3.9 days of hospitalization for the historical control group. The inpatient group (N = 39) was significantly more likely to require hospitalization >6 days (P = 0.0004), with a trend toward more frequent upper urinary tract recurrences (6/39 vs. 1/34, P = 0.08). The cost analysis revealed a 3-fold difference between outpatient and inpatient therapy ($1,100 vs. $3,350, P < 0.001). Conclusions: The outpatient treatment of selected patients with pyelonephritis in pregnancy as a promising approach to reducing costs warrants further investigation.

Extracellular release of reactive oxygen species from human neutrophils upon interaction with Escherichia coli strains causing renal scarring

The production of reactive oxygen metabolites by neutrophils plays a key role in the host defense against invading microorganisms and in tissue damage resulting from infection. In the present study we measured the ability of different uropathogenic Escherichia coli strains to induce generation of oxygen metabolites upon interaction with human neutrophils. The strains were selected to represent two groups of patients with recurrent episodes of acute pyelonephritis: one with renal scars (12 strains) and one without renal scarring (11 strains). The majority of strains (from both groups) induced a pronounced neutrophil respiratory burst activity. When the intracellular and extracellular oxidative responses were measured separately, it was found that the response induced by nonscarring strains was primarily of intracellular (intraphagosomal) origin, whereas a proportionally larger fraction of the response induced by the scarring strains was extracellular. Since reactive oxygen products are toxic to the renal tissue, this release can be of importance in the development of renal scars.

A Five-Year Prospective Follow-Up of Women with Non-Obstructive Pyelonephritic Renal Scarring

Fifty women with pyelonephritic renal scarring were prospectively followed for five years and the changes in renal function were related to blood pressure control, plasma renin activity, urinary albumin excretion and the incidence of urinary tract infections (UTI). Five patients (10%) developed end stage renal disease. All these patients had bilateral disease, proteinuria and anti-hypertensive treatment at presentation. The mean +/- SD glomerular filtration rate (GFR) of all patients with renal scarring was 74 +/- 27 ml/min x 1.73 m2 at presentation which was significantly lower than the GFR in 55 patients with a recent episode of acute pyelonephritis (p less than 0.001) and 10 healthy controls (p less than 0.001). GFR and age corrected GFR decreased significantly during follow-up (p less than 0.001) and p less than 0.02 respectively). The decrease in GFR was significantly higher in patients with bilateral scarring, in patients on blood pressure treatment and in patients with an episode of symptomatic UTI during follow-up. Eight patients (16%) had antihypertensive treatment at presentation and another 11 patients (26%), of whom 10 had bilateral scarring, developed hypertension (greater than 140/90 mmHg) during follow-up. Seventy-five per cent of all patients had symptomatic UTI and 40% had an episode of acute pyelonephritis during follow-up. In conclusion, patients with pyelonephritic scarring have a high incidence of UTI and are at high risk of developing renal failure and hypertension. It is essential that recurrent episodes of symptomatic UTI are treated promptly and that blood pressure is monitored carefully in these patients.

Ileal Bladder Substitute: Antireflux Nipple or Afferent Tubular Segment?(1)

Spheroidal bladder substitutes made from double-folded ileal segments, similar to Goodwin's cup-patch technique, are devoid of major coordinated wall contractions. This, together with the reservoir's direct anastomosis to the membranous urethra, prevents major intraluminal pressure peaks and assures a residue-free voiding of sterile urine. In order to determine whether, under these conditions, an afferent tubular isoperistaltic ileal segment of 20-cm length protects the upper urinary tract as efficiently as an antireflux nipple, 60 male patients who were subjected to radical cystectomy were prospectively randomised to groups in which a bladder substitute was formed together with either of these 2 antireflux devices. An analysis of the results obtained in 20 patients from each group who could be followed for more than 1 year (median observation time 30 and 36 months) showed no differences between the groups in metabolic disturbances, kidney size, reservoir capacity, diurnal and nocturnal urinary continence, the incidence of urinary tract infection or episodes of acute pyelonephritis. Later than 1 year postoperatively, intravenous urograms of the renoureteral units of 25% of the patients with antireflux nipples showed persistent but generally slight dilatation of the upper urinary tracts. This observation was significantly more frequent than it was in patients with afferent tubular segments. Urodynamic and radiographic studies showed that the competence of the antireflux nipples was secured by the raised surrounding intravesical pressure. This, however, also resulted in a transient functional obstruction, and a gradual rise of the basal pressure in the upper urinary tracts was recorded. In patients with afferent ileal tubular segments, contrast medium could be forced upwards into the renal pelvis when the bladder substitutes were overfilled. However, despite raised intravesical pressures, peristalsis in the isoperistaltic afferent tubular segment gradually returned contrast medium back to the reservoir. Our results suggest that the combination of an ileal low-pressure reservoir together with an afferent tubular isoperistaltic limb is at least as good as an antireflux nipple valve. Moreover, the use of the afferent ileal limb makes it possible to resect the distal and often diseased ureters together with the paraureteric lymphatics at a safe distance from the bladder tumor. This avoids also distal ischemic ureteric stenosis and makes possible a simple end-to-side ureterointestinal anastomosis with a small complication rate.

A five-year prospective follow-up of women with non-obstructive pyelonephritic renal scarring

Fifity women with pyelonephritic renal scarring were prospectively followed for five years and the changes in renal function were related to blood pressure control, plasma renin activity, urinary albumin excretion and the incidence of urinary tract infections (UTI). Five patients (10%) developed end stage renal disease. All these patients had bilateral disease, proteinuria and anti-hypertensive treatment at presentation. The mean ± SD glomerular filtration rate (GFR) of all patients with renal scarring was 74 ± 27 ml/min × 1.73 m2 at presentation which was significantly lower than the GFR in 55 patients with a recent episode of acute pyelonephritis (p < 0.001) and 10 healthy controls (p < 0.001). GFR and age corrected GFR decreased significantly during follow-up (p < 0.001 and p < 0.02 respectively). The decrease in GFR was significantly higher in patients with bilateral scarring, in patients on blood pressure treatment and in patients with an episode of symptomatic UTI during follow-up. Eight patients (1...

Phenotypic differences and characteristics of pyelonephritogenic strains of Escherichia coli isolated from children and adults

We examined the frequency of bacterial strains expressing cell surface hydrophobicity, P-fimbriae, mannose-resistant haemagglutination (MRHA), type I fimbriae, production of aerobactin, haemolysin synthesis (Hly), production of cytotoxic necrotising factor (CNF) and HeLa cell adherence in 126 strains of Escherichia coli isolated from children (n = 65) and women (n = 61) with acute non-obstructive pyelonephritis. Previous investigations have shown that pyelonephritogenic strains of E. coli more often express hydrophobic properties, P-fimbriae, MRHA, aerobactin-mediated iron uptake, Hly and CNF production than strains isolated from the faecal flora of healthy persons. The objective of the present study was to examine phenotypic differences between strains of E. coli obtained from children with their first episode of acute pyelonephritis and strains from women with non-obstructive acute pyelonephritis. Of the pyelonephritogenic strains of E. coli isolated from children, 98% expressed cell surface hydrophobic properties compared to 82% isolated from adults (P = 0.004). Strains from children and adults had the same ability to assimilate iron and equally often expressed P-fimbriae, MRHA and type I fimbriae. Strains from children with acute pyelonephritis more significantly expressed Hly (72%) and CNF (58%) than did pyelonephritogenic strains from adults (49 and 37% respectively, P = 0.013 and P = 0.028 respectively). The frequency of HeLa cell adherence was similar and low in both groups. The phenotype aerobactin+ Hly+ and Hly+CNF+ was found significantly more often in pyelonephritogenic strains from children than in strains from adults (P = 0.006 and P = 0.028 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Natural history of “lower” urinary tract infections

Our current knowledge of the long-term outcome of uncomplicated urinary tract infections in women is based on a re-evaluation of the criteria for defining pyelonephritis at autopsy, careful description of the causes of renal disease among patients entering dialysis and transplant programs, long term observation of patients, and epidemiologic studies which have attempted to determine the association of bacteriuria with mortality. The weight of the evidence favors the conclusion that although urinary tract infections can produce severe impairment of renal function, this is rare in the absence of a major predisposing factor such as obstruction, calculus, reflux, abnormalities of the voiding mechanism or diabetes. The predisposing lesions, however, may go undetected until heralded by episodes of acute pyelonephritis or by renal failure. Unfortunately, urinary tract infections are so common that it is difficult to distinguish the population at greatest risk. The possible role of renal damage produced by autoimmune mechanisms following infection needs continued study.

Special virulence of the Escherichia coli O1:K1:H7 clone in acute pyelonephritis

The relationship between acute-phase responses and bacterial properties was studied in a population of 88 children with their first known episode of acute pyelonephritis. One strain from each patient was included in the study. Eighty-four of the patients were infected with Escherichia coli, which was assigned a clonotype according to the O:K:H stereotype; 55 patients carried one of the 12 multiply occurring clones. Globotetraosylceramide-specific (globo+) adhesion was present in 90% of these 12 clones, compared with 62% in the remaining 29 singly occurring clones. The patients infected with globo+ strains had significantly increased inflammatory reactions compared with patients with globo- strains. The O1:K1:H7 strain was the single most frequent clone (n = 14) that always expressed globo+ adhesins. Patients infected with O1:K1:H7 had an inflammatory response similar to that of other globo+ infections, but had a shorter duration of symptoms before diagnosis, higher fever, and higher peripheral leukocyte count. These results demonstrate special virulence of the O1:K1:H7 clone, reflected by the acuteness of onset of infection.

Secretor state and renal scarring in girls with recurrent pyelonephritis

The non-secretor phenotype was significantly associated with the occurrence of renal scarring among patients with recurrent pyelonephritis. Girls (n = 77) with recurrent pyelonephritis were followed from the first known episode of infection for up to twelve years with repeated radiological investigations. They were divided into two categories: those with renal scars (n = 35) and those who did not develop scars (n = 42). There was a significant over-representation of non-secretors among the patients with scarring, (14/35, 40%) compared to the healthy controls (21.8%, P less than 0.05). The frequency of non-secretors among the girls who did not develop scars in spite of repeated episodes of acute pyelonephritis was not significantly different from the healthy controls (9/42, 21% n.s.). This study provides a basis for analysis of the influence of secretor state on host-parasite interaction in the urinary tract.

Secretor state and renal scarring in girls with recurrent pyelonephritis

The non-secretor phenotype was significantly associated with the occurrence of renal scarring among patients with recurrent pyelonephritis. Girls ( n = 77) with recurrent pyelonephritis were followed from the first known episode of infection for up to twelve years with repeated radiological investigations. They were divided into two categories: those with renal scars ( n = 35) and those who did not develop scars ( n = 42). There was a significant over-representation of non-secretors among the patients with scarring, ( 14 35 , 40%) compared to the healthy controls (21.8%, P < 0.05). The frequency of non-secretors among the girls who did not develop scars in spite of repeated episodes of acute pyelonephritis was not significantly different from the healthy controls ( 9 42 , 21%, n.s.). This study provides a basis for analysis of the influence of secretor state on host-parasite interaction in the urinary tract.

Diagnostic Potential of Urinary Enzymes and β2‐Microglobulin in Acute Urinary Tract Infection

Urinary excretions of beta 2-microglobulin (beta 2M), N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase, beta-glucuronidase, acid and neutral alpha-glucosidase as indicators of proximal tubular dysfunction were measured in patients with acute upper and lower urinary tract infection (UTI) and fever of non-renal origin. The sensitivity of beta 2M was 67% and of NAG 49% as assessed in more than 100 episodes of acute pyelonephritis. Combined use of beta 2M and NAG increased the sensitivity to 75%. The degree of beta 2-microglobulinuria and enzymuria was comparable in patients with acute pyelonephritis and fever due to non-renal infections. The excretion of beta 2M and the various enzymes was too variable and unpredictable in individual cases to be useful as diagnostic indicator. In localizing an acute UTI, tests for proximal tubular dysfunction seem to be of no more clinical value than properly measured body temperature.

Virulence-associated traits in Escherichia coli causing first and recurrent episodes of urinary tract infection in children with or without vesicoureteral reflux.

Virulence-associated properties of 606 urinary isolates from 174 children with urinary tract infections were related to severity of infection and factors increasing host susceptibility, e.g., vesicoureteral reflux (grade II or higher) and P1 blood group phenotype. A high proportion of strains of Escherichia coli causing first or recurrent episodes of acute pyelonephritis in children without reflux expressed the previously noted high frequency of certain O antigens, resistance to serum killing, hemolysin production, and adhesive capacity. A significantly lower frequency of these traits and a higher frequency of non-E. coli were seen among isolates from children with pyelonephritis and reflux, cystitis, and asymptomatic bacteriuria. Reflux was thus found to be a determinant of the level of infection and of the bacterial properties required to produce pyelonephritis. Efforts aimed at preventing or treating urinary tract infection by interfering with "virulent" bacteria may be of less value in patients with recurrent pyelonephritis and reflux, who are most likely to develop renal scars.

Acquired Renal Scars in Children

To determine the important factors involved in the etiology of renal scarring we studied 37 children with renal scars seen at our hospital since 1965. This is the second largest series reported to date. Children who had neurogenic bladders or any structural abnormalities of the urinary tract other than vesicoureteral reflux were excluded. The study group included 36 girls and 1 boy. The average age at first detection of renal scars was 5.7 years.Acute pyelonephritic episodes, which were treated early and aggressively, infrequently led to renal scarring. However, the initial prolonged or poorly treated episode of acute pyelonephritis was followed invariably by the development of renal scarring.The severity of renal scarring was related to the grade of vesicoureteral reflux (p less than 0.05), although some scars did develop in the absence of reflux. Neither the shape and position of the ureteral orifice nor the ureteral tunnel length correlated with the severity of renal scarring. Treatment with prophylactic antibiotics may have lessened the severity of renal scarring (0.1 less than p less than 0.2) but treatment with reimplantation surgery did not appear to alter the course of renal scarring. This study suggests that the key to the prevention of renal scarring is the early and aggressive treatment of acute pyelonephritis.

COMPARISON OF URINE BAG-CHANGING REGIMENS IN ELDERLY CATHETERISED PATIENTS

Daily and weekly bag-changing regimens were compared in 12 elderly catheterised patients with reference to their clinical condition, leakage or blockage of the catheters, and the bacteriological state of the urine. Latex Foley catheters were used for the first 3 months and silastic catheters for the second 3 months of the study. All patients had bacteriuria throughout the study, and the average number of bacterial species isolated from each specimen was 3·8. There were no significant clinical or bacteriological differences between the patients on daily and those on weekly bag change. Although significantly more episodes of pyrexia were recorded during latex than during silastic catheterisation there was no correlation between these episodes and the bacteriological state of the urine. Of the 9 courses of antibacterial treatment given during the 6 months, 7 were for indications other than urinary tract infection. There were no episodes of acute pyelonephritis. There were 148 episodes of pyrexia unrelated to any clinical symptoms or signs. Only 2 were treated with antibiotics; the remainder subsided without treatment.

The management of vesicoureteral reflux in children with neurogenic bladders.

Sixty-two children with 90 refluxing ureters and neurogenic bladder dysfunction were initially managed by clean intermittent catheterisation. The upper urinary systems demonstrated hydronephrosis and/or parenchymal scarring in 57 kidneys and were normal in 33. Each child was placed on low dose antimicrobials and followed nonoperatively unless there was evidence of a febrile urinary tract infection or upper tract deterioration at which point antireflux surgery or urinary diversion was performed. Our experience suggests that children with neurogenic bladders and reflux may be safely managed by clean intermittent catheterisation and that low or moderate degrees of reflux may actually disappear. If recurrent bacilliuria or febrile urinary infections are noted then ureteroneocystostomy is a reliable and effective treatment option in neurogenic bladder disease provided that the bladder dysfunction is controlled. Higher grades of reflux have proven more difficult to manage and in our experience the reflux has not spontaneously abated and frequently there are associated episodes of acute pyelonephritis and renal damage. Because of our success with reimplantation surgery, we now favour early ureteroneocystostomy in such circumstances. With effective management of the neurogenic bladder dysfunction with intermittent catheterisation permanent urinary diversion should only occasionally be necessary because of vesicoureteral reflux.

Localization of Gram Negative Urinary Tract Infection by Immunofluorescence in Infants and Children

Barnett, G. R. and Abbott, G. D. (1978). Aust. Paediatr. J., 14, 143–146. Localization of gram negative urinary tract infection by immunofluorescence in infants and children. Bladder urine samples from 97 gram negative urinary tract infections (U.T.Is) in infants and children were tested for antibody coated bacteria (A.C.B.) by immunofluorescence (I.F.). A.C.B. were detected in 14 of 44 episodes of acute pyelonephritis, one of 20 episodes of probable cystitis and five of 33 episodes of asymptomatic bacteriuria. Bladder washout localization reinforced the conclusion that negative I.F. tests are common in upper U.T.Is in infants and children.An association between A.C.B. and renal scarring was observed. Eight of 17 patients with A.C.B. had reflux nephropathy compared with four of 49 patients without A.C.B. Limitations of the test as a screening procedure for renal scarring were evident, however, after finding nine patients with A.C.B. and no renal scarring as well as four patients with renal scarring and no A.C.B.

On Controversial and Open Questions about the Course and Complications of Non‐Obstructive Urinary Tract Infection in Adult Women

ABSTRACT. In an earlier report of the results of the initial medical examination in our population study from the period 1969–75 on non‐obstructive urinary tract infection (UTI) in non‐pregnant women, it was shown that the negative conclusions published by others on the importance of UTI and the value of early diagnosis rested on insecure grounds, owing partly to the test used in determination of renal function and partly to the selection of the material for the population studies. After, in most cases, long‐term treatment of 142 bacteriuric women there was significant improvement of the defective maximum urinary concentration ability, which continued until the end of the follow‐up period. There was no significant difference between the subgroups of women who had had and had not had symptomatic UTI in the past. 659 women were followed up for 36–80 months. They were divided into the same series as those to which they belonged initially in the earlier study: 1) 212 controls with no past history of subjective symptoms of upper or lower UTI and no urinary abnormalities, i.e. neither bacteriuria nor pyuria at the time of the first medical examination; 2) 180 women with a past history of symptomatic UTI but no urinary abnormalities; 3) 173 women with sterile pyuria; and 4) 94 women with bacteriuria/pyuria. About 40% of the women in the latter two series had no past history of UTI. In comparison with the other series, series 1 had a significantly lower number of women with symptomatic UTI and newly diagnosed hypertension during the follow‐up period as well as of women with bacteriuria and/or pyuria at the final examination. Between series 2, 3, and 4 there were significant differences mainly with respect to the final finding of pyuria; the number of such cases was highest in series 3. The importance of symptomatic UTI as a criterion is limited by the overlapping that is represented by the women in series 3 and 4 who had no past history of such symptoms at the time of the initial medical examination. Systematic radiological re examinations could not be carried out because of inadequate resources. The controversial question of a possible relation between non‐obstructive UTI and progressive renal damage in normotensive adult women is illustrated by the development of bilateral papillary necrosis and/or shrinking of the kidneys during a 6.1 (1–15) years' interval following the finding of a normal i.v. urogram in 33 selected patients aged 49.0 (26–71) who had a past history of UTI for 14.7 (2–40) years. Just over two thirds of them had had episodes of acute pyelonephritis. In two additional cases i.v. urography showed no abnormalities but renal angiography revealed parenchymal damage with scars. Furthermore, biopsy showed evidence of “chronic pyelonephritis” with an acute inflammatory process in a patient with normal urogram and normal angiogram. The reliability of radiographic methods and the possibility of demonstrating “progressive kidney damage” by i.v. urography in population studies with a relatively short follow‐up period are discussed. To what extent patients with UTI run the risk of progressive kidney damage of clinical importance still seems to be an open question.