Explore the vast range of titles available.

Renal imaging is recommended for children after a first documented urinary tract infection. In this prospective study, 309 children between the ages of one month and two years underwent renal imaging studies (technetium-99m–labeled dimercaptosuccinic acid scanning and renal ultrasonography) within 72 hours after the diagnosis of urinary tract infection, voiding cystourethrography one month later, and repeated scanning six months later. Management was not changed by the finding of ultrasonographic abnormalities (in 12 percent of the children). Monitoring with urinalysis and culture appears to be as effective as imaging studies. Imaging studies are the standard of care for young children with a first urinary tract infection. The purpose is to identify possible urinary tract abnormalities, such as vesicoureteral reflux, obstruction of the urinary tract, ureteroceles, acute inflammation, and renal scarring, that may predispose the child to recurrent infections or adverse long-term outcomes. Practice guidelines from the American Academy of Pediatrics recommend a voiding cystourethrogram and a renal ultrasonogram after a first urinary tract infection in children 2 to 24 months of age. 1 Although imaging studies are performed routinely, evidence of their value in altering management or improving outcomes is limited. . . .

Decisions regarding disposition and treatment in patients with pyelonephritis should be guided by assessment of the likelihood of pathogen resistance to antimicrobial agents and by patient factors (e.g., illness severity, coexisting conditions, and psychosocial situation).

A Panel of International Experts was convened by the Infectious Diseases Society of America (IDSA) in collaboration with the European Society for Microbiology and Infectious Diseases (ESCMID) to update the 1999 Uncomplicated Urinary Tract Infection Guidelines by the IDSA. Co-sponsoring organizations include the American Congress of Obstetricians and Gynecologists, American Urological Association, Association of Medical Microbiology and Infectious Diseases–Canada, and the Society for Academic Emergency Medicine. The focus of this work is treatment of women with acute uncomplicated cystitis and pyelonephritis, diagnoses limited in these guidelines to premenopausal, non-pregnant women with no known urological abnormalities or co-morbidities. The issues of in vitro resistance prevalence and the ecological adverse effects of antimicrobial therapy (collateral damage) were considered as important factors in making optimal treatment choices and thus are reflected in the rankings of recommendations.

PurposeEmphysematous pyelonephritis (EPN) is an acute, severe necrotising infection of the kidney. There has been a shift from early nephrectomy to conservative methods. We conducted a meta-analysis to assess the impact of risk factors and treatment choices on outcomes in EPN.MethodsWe conducted a database search of all studies in English, reporting more than 12 patients of EPN from 1980 to 2020. We compiled the demographics, clinical presentations, risk factors, critical diagnostic results, treatment modalities and outcomes, including mortality.ResultsWe identified 37 observational studies, 32 retrospective and 5 prospective. The studies reported on 1146 patients, of which 790(68.9%) were female, and 946 (82.5%) were diabetic. In addition, 184 (16.1%) patients had stones, and 235 (20.5%) had obstructive uropathy. Fever and flank pain were the most frequent symptoms. The most common clinical features were pyuria, fever, flank tenderness, and tachycardia. E. coli, Klebsiella pneumoniae and Proteus were the most frequent organisms isolated. X-ray KUB and ultrasound were used as initial diagnostic modalities, but CT scan was the usual diagnostic and confirmatory investigation. Confusion, shock, thrombocytopenia, sepsis, emergency nephrectomy and hyponatremia were significantly associated with mortality. In particular, confusion and hyponatremia were associated with a sevenfold increase in mortality risk. There was no evidence that diabetes, stones, obstructive uropathy, AKI or proteinuria was associated with higher mortality. Nevertheless, 143 of the total 1146 patients died (12.5%). While 26% of the patients who had upfront emergency nephrectomy died, only 9.7% and 10% of patients with medical management and medical management plus minimally invasive treatments died. However, patients that failed medical and minimally invasive treatments and needed salvage emergency nephrectomy had a mortality of upwards of 27%.ConclusionThe risk factors for mortality in emphysematous pyelonephritis are shock, thrombocytopenia, confusion, hyponatremia and emergency nephrectomy. Conservative and minimally invasive treatment should be the initial management strategy for emphysematous pyelonephritis as they carry lesser mortality risks. The presence of risk factors may help predict the subset of patients who need aggressive treatment and minimally invasive treatment modalities or early nephrectomy.

Acute pyelonephritis is one of the most serious bacterial illnesses during childhood. Escherichia coli is responsible in most cases, however other organisms including Klebsiella, Enterococcus, Enterobacter, Proteus , and Pseudomonas species are being more frequently isolated. In infants, who are at major risk of complications such as sepsis and meningitis, symptoms are ambiguous and fever is not always useful in identifying those at high risk. A diagnosis of acute pyelonephritis is initially made on the basis of urinalysis; dipstick tests for nitrites and/or leukocyte esterase are the most accurate indicators of infection. Collecting a viable urine sample for urine culture using clean voided methods is feasible, even in young children. No gold standard antibiotic treatment exists. In children appearing well, oral therapy and outpatient care is possible. New guidelines suggest less aggressive imaging strategies after a first infection, reducing radiation exposure and costs. The efficacy of antibiotic prophylaxis in preventing recurrence is still a matter of debate and the risk of antibiotic resistance is a warning against its widespread use. Well-performed randomized controlled trials are required in order to better define both the imaging strategies and medical options aimed at preserving long-term renal function.

Emphysematous pyelonephritis is a rare, life-threatening necrotizing infection that is typically characterized by classic urinary symptoms. However, it is exceptionally rare for emphysematous pyelonephritis to manifest with predominant gastrointestinal symptoms, a deceptive mimicry that often masks the underlying renal pathology and leads to significant diagnostic delays. We report the case of a woman in her 60s with type 2 diabetes whose initial presentation was limited to vomiting and diarrhea, suggesting acute gastroenteritis. In the absence of typical urological distress, her condition rapidly worsened, and she developed septic shock and altered mental status within 48 h. Computed tomography confirmed Huang–Tseng class 3B emphysematous pyelonephritis with extensive destruction of the right renal parenchyma. Recognizing the irreversible tissue necrosis and failure of medical therapy, a decisive transition to emergency nephrectomy was performed. This timely surgical intervention successfully arrested the fulminant progression, leading to hemodynamic stabilization and recovery. This case underscores that emphysematous pyelonephritis rarely masquerades as gastroenteritis; in diabetic patients, such atypical manifestations followed by rapid clinical deterioration necessitate immediate computed tomography evaluation. Furthermore, when imaging reveals extensive gas formation and clinical stability is lost, prompt and resolute surgical source control is a critical, life-saving measure for ensuring patient survival.

Background and Objectives: Acute and obstructive pyelonephritis (AOP) management, despite advancements in diagnostic imaging and antimicrobial therapy, is characterized by delayed recognition and increasing antimicrobial resistance. This review aimed to summarize current evidence regarding the clinical characteristics, microbiological spectrum, biomarkers, and imaging findings associated with AOP. Materials and Methods: A systematic review was conducted according to PRISMA guidelines and registered in PROSPERO (CRD420251162736). Literature searches were performed across the PubMed, Scopus, and Web of Science databases for articles published between January 2014 and 31 March 2025 using the term “acute obstructive pyelonephritis”. Inclusion criteria comprised original full-text English-language studies, published in the last 10 years and conducted in adults, reporting clinical, laboratory, microbiological, and imaging characteristics. Exclusion criteria are letters to the editor, expert opinions, case reports, conference or meeting abstracts, reviews, and redundant publications; having unclear or incomplete data; and being performed on cell cultures or on mammals. The quality of included studies was assessed using the Newcastle–Ottawa Scale. Results: Twenty-three studies met the inclusion criteria. AOP predominantly affected elderly patients with comorbidities, especially diabetes mellitus and urinary tract obstruction. Predictors of septic shock included thrombocytopenia, hypoalbuminemia, elevated procalcitonin (>1.12 µg/L), presepsin, and a neutrophil-to-lymphocyte ratio ≥ 8.7. Escherichia coli remained the leading pathogen (60–95%) with extended-spectrum β-lactamase (ESBL) rates between 20 and 70%, followed by Klebsiella pneumoniae. CT demonstrated 71–100% sensitivity for detecting obstructive complications, confirming its superiority over ultrasound, while MRI provided comparable diagnostic accuracy in selected cases. Source control through double-J stenting or percutaneous drainage significantly improved survival. Conclusions: AOP requires prompt recognition and early decompression to prevent sepsis-related mortality. Biomarkers such as procalcitonin, presepsin, and neutrophil to lymphocyte ratio enhance risk stratification, while CT remains the gold-standard imaging modality. The increasing prevalence of ESBL-producing pathogens underscores the need for antimicrobial stewardship and individualized therapeutic strategies guided by local resistance data.

Abstract Background The diagnosis of pyelonephritis in cats is challenging and development of a noninvasive and accurate biomarker is needed. Hypotheses Serum amyloid A (SAA) is increased in cats with pyelonephritis, but not in cats with other urinary tract diseases. Animals A cohort of 125 cats (149 observations). Methods This was a prospective study. Group 1 included cats with a diagnosis of pyelonephritis either confirmed by bacterial culture of pelvic urine (Group 1a) or presumed (1b). Group 2 included cats for which pyelonephritis was ruled out (with certainty: Group 2a or judged unlikely: Group 2b). SAA concentration was compared between groups, and accuracy of SAA for the diagnosis of pyelonephritis was calculated using a Receiver Operating Characteristic (ROC) curve analysis. Results Median SAA concentration was significantly higher in Group 1a (86.8 mg/L [73.3; 161.5]; n = 8) than in Group 2a (4 mg/L [1.8; 5.6], n = 19; P < .001) and in Group 2b (5.4 mg/L [3.1; 9.7], n = 113; P < .001). It was also significantly higher in Group 1b (98.8 mg/L [83.1; 147.3]; n = 9) than in Group 2b (P < .001) and Group 2a (P < .001). Optimal diagnostic cut-off for SAA concentration was 51.3 mg/L. yielding a sensitivity of 88% (95% confidence interval: [64%; 99%]) and a specificity of 94% (95% confidence interval: [88%; 97%]). Conclusions and Clinical Importance Measurement of SAA could be used to rule out pyelonephritis in the case of low suspicion of the disease. Increased SAA concentration is suggestive of pyelonephritis despite a lack of specificity.

Abstract Background The clinicopathologic aspects of pyelonephritis have not been reported in companion animals. Hypothesis/Objectives To evaluate the prevalence of pyelonephritis diagnosed in dogs in a academic referral population, describe the clinical signs and the diagnostic test results in dogs with pyelonephritis, and identify concurrent disorders in order to determine potential risk factors for pyelonephritis. Animals Forty-seven dogs with a histopathologic diagnosis of pyelonephritis from the teaching hospitals of three Canadian veterinary colleges. Methods Retrospective case series. Review of medical records and renal histologic sections. Results Pyelonephritis was diagnosed in 0.4–1.3% of the cases at necropsy. Clinical signs included anorexia or inappetence (n = 27, 57%), lethargy (n = 24, 51%), vomiting (n = 17, 36%), and dehydration (n = 12, 25%). Thirty-five dogs (75%) had concomitant disease(s). Escherichia coli was the most common pathogen isolated (37%). Pyelonephritis was classified as acute (n = 12, 26%), subacute (n = 9, 19%), and chronic (n = 26, 55%) disease; and mild (n = 7, 15%), moderate (n = 11, 24%), and severe (n = 28, 61%). Fever was significantly associated with histopathologically subacute pyelonephritis (P = 0.01). Conclusions In referral hospitals, pyelonephritis has a very low prevalence at necropsy. Nonspecific clinical presentation, concomitant diseases, and high variability in the diagnostic tests results make the antemortem diagnosis of pyelonephritis challenging. Neither the histopathologic stage nor the severity of the pyelonephritis was associated with fever, lumbar pain, or signs of a urinary tract infection (ie, lower urinary tract infection, upper urinary tract infection, or both) except for subacute pyelonephritis which was associated with fever.

In this study, we aimed to evaluate the usefulness of urinary β2-microglobulin (U-β2MG) for diagnosing acute focal bacterial nephritis (AFBN) among upper urinary tract infections (UTIs). This retrospective study was performed at a single institution and included patients younger than 16 years of age diagnosed with upper UTIs. Patients were divided into the AFBN group and acute pyelonephritis (APN) group. Levels of U-β2MG corrected using urinary creatinine (U-β2MG/Ucre) were compared between groups. A multiple regression analysis was performed using Log(U-β2MG/Ucre) as a dependent factor and the diagnosis (AFBN or APN), age, sex, hydronephrosis grade, urinary pH, and fever interval before admission as independent factors. To discriminate AFBN and APN, thresholds of U-β2MG/Ucre and C-reactive protein (CRP) levels were measured using the receiver-operating characteristic curve. Nineteen patients and 37 patients with AFBN and APN, respectively, were analyzed. The U-β2MG/Ucre level differed significantly between the AFBN and APN groups (10762 μg/gCr vs. 1525 μg/gCr, respectively; P = 0.007). The multiple regression analysis indicated that the Log(U-β2MG/Ucre) value of the AFBN group was considerably higher than that of the APN group (P = 0.004). The threshold values of U-β2MG/Ucre and CRP levels were 2070 μg/gCr and 5.7 mg/dL, respectively. Sensitivity and specificity were 0.95 and 0.68, respectively, when both thresholds were used. Conclusions : The U-β2MG/Ucre level of patients with AFBN was significantly higher than that of patients with APN. Therefore, U-β2MG/Ucre could be used to discriminate between AFBN and APN. What is Known: • U-β2MG can aid in discriminating between upper and lower UTIs; however, using both U-β2MG and procalcitonin allows for more accurate differentiation What is New: • U-β2MG may be useful for discriminating between AFBN and APN in upper UTIs. Assessing both U-β2MG and CRP levels may improve the diagnosis of AFBN without invasive imaging tests