Acute Focal Bacterial Nephritis Caused by Staphylococcus simulans.

A toddler girl presented to our hospital with a fever that lasted for five days. She had no prior history of urinary tract infections or contact with farm animals. Investigations revealed a diagnosis of acute focal bacterial nephritis (AFBN), and we initiated antimicrobial therapy with ampicillin and cefmetazole. On day five, methicillin-resistant coagulase-negative staphylococci were detected in her urine culture, and we changed the antibiotics to vancomycin. Antibiotic therapy was continued for 21 days, with no recurrence of fever. Finally, the bacteria were identified as Staphylococcus (S.) simulans, which is a common farm animal pathogen. Clinicians should be aware of the possibility of AFBN caused by S. simulans, even if the patient has no prior history of close contact with farm animals. If a rare organism is detected in urine culture during AFBN treatment, the patient should be treated with appropriate antibiotics for the pathogen.

Acute focal bacterial nephritis and prolonged fever.

Acute focal bacterial nephritis (AFBN) is characterised by a complicated upper urinary tract infection ranging from acute pyelonephritis to renal abscess. Timely diagnosis of AFBN is important because antibiotic therapy of longer duration is required. A 10-year-old boy presented with fever for 5 days and bilateral flank pain. He was oriented and cooperative but appeared ill. Physical examination did not reveal any oedema or costovertebral angle tenderness. Acute phase reactants such as erythrocyte sedimentation rate and C-reactive protein were raised, serum creatinine was 1.25 mg/dL (0.31-0.88) and leucocyte esterase was positive in the urine. Ultrasonographic examination demonstrated bilaterally enlarged kidneys with increased echogenicity. Because of the high creatinine level, abdominal magnetic resonance imaging (MRI) was performed instead of computed tomography (CT) for further evaluation. The MRI showed an increase in the size of both kidneys, renal cortical heterogeneity and multiple cortical nodular lesions with diffusion restriction (constrained Brownian movement of water molecules) on diffusion-weighted MRI. A negative urine culture result in children presenting with fever and abdominal pain may mislead the clinicians, causing them to miss a nephro-urological diagnosis. It is therefore recommended that patients in whom the cause of fever cannot be determined be scanned by ultrasound and examined by CT or MRI so that undiagnosed and/or suspected cases of AFBN might be detected.

Acute Lobar Nephronia in an infant presented as a renal tumor.

A case report of a 02-month-old infant referred to us with incidental bilateral renal masses on ultrasound, which was reported as nephroblastoma/Wilms tumor on CT scan, no signs, and symptoms of infection. Urine and blood cultures were negative, which led to a percutaneous renal biopsy which showed Acute Lobar Nephronia. The infant was started intravenous antibiotics which resulted in the resolution of bilateral renal masses on serial ultrasounds.

Comparison of imaging findings between acute focal bacterial nephritis (acute lobar nephronia) and acute pyelonephritis: a preliminary evaluation of the sufficiency of ultrasound for the diagnosis of acute focal bacterial nephritis.

OBJECTIVE: The recommended durations of treatment for acute focal bacterial nephritis (AFBN) and acute pyelonephritis (APN) are different. This study aimed to clarify the sonographic findings used to differentiate AFBN from APN during diagnosis and to compare these findings with those obtained using computed tomography (CT). METHODS: Eleven children with urinary tract infection who underwent contrast-enhanced CT and ultrasound examinations within a 24-h period were included. Diagnoses of AFBN and APN were established using CT data as the gold standard; viz., a focal area of poor enhancement is observed in AFBN but not in APN. The following ultrasound findings were evaluated: focal loss of corticomedullary differentiation (one/multiple), focal hyperechogenicity, abscess formation, and diffuse nephromegaly. Fisher's exact test was used for statistical analysis. RESULTS: Of the 11 patients, 8 had AFBN and 3 had APN. The two groups differed significantly in the incidence of a focal loss of corticomedullary differentiation (present/absent, 8/8 vs. 0/3; p = 0.01) but not in the incidence of focal hyperechogenicity, abscess formation, and diffuse nephromegaly (present/absent, 2/8 vs. 0/3, p > 0.99; 1/8 vs. 0/3, p > 0.99; and 5/8 vs. 3/3, p = 0.49, respectively). The poorly enhanced area used to diagnose AFBN on CT images appeared as a focal loss of corticomedullary differentiation in ultrasound examinations. CT revealed multiple lesions in two cases in which ultrasound revealed only single lesions. CONCLUSION: In our small cohort, ultrasound could be adequately used to diagnose AFBN based on the presence of a focal loss of corticomedullary differentiation. CT may not be required to differentiate AFBN from APN.

[Predictive markers of acute focal bacterial nephritis. A multicentre case-control study]. / Marcadores predictivos de nefritis focal bacteriana aguda. Estudio multicéntrico casos-control.

INTRODUCTION: Acute focal bacterial nephritis is an interstitial bacterial infection, localised in the renal parenchyma, which can be more serious than acute pyelonephritis. The aim of this study is the analysis of predictive factors that may lead to its early diagnosis, which is essential for an adequate therapeutic approach. PATIENTS AND METHODS: A retrospective, multicentre case and control study. The participant centres were hospitals in Castellon and Valencia. The study period was 2010-2018, with the cases being patients with focal bacterial nephritis and the patients with pyelonephritis as controls. RESULTS: A total of 158 (1:1) patients were included. The median age of the cases was 2 years and there were 75% females. There were no differences in the clinical presentation. In the univariate analysis, focal nephritis was associated with malformations of the urinary tract, bacteraemia, the neutrophil count, and procalcitonin, as well as febrile convulsions of borderline significance. Procalcitonin values ≥2 ng/ml had an OR of 4.9 (95%CI; 1.77-13.85) of presenting with focal nephritis. In the multivariate analysis, the urological malformations still maintained statistical significance and borderline significance for procalcitonin. CONCLUSIONS: The urinary tract malformations predispose the development of focal bacterial nephritis. In patients with a urinary tract infection and predictive factors of acute focal bacterial nephritis it would be worthwhile performing a renal Doppler ultrasound in the acute phase for its appropriate diagnosis and treatment.

Acute Focal Bacterial Nephritis: Two Cases and Review of the Literature.

RATIONALE: Acute focal bacterial nephritis (AFBN) has mainly been reported in pediatrics. It may be an underdiagnosed condition in adults because it resembles acute pyelonephritis (APN) in its clinical presentation. PRESENTING CONCERNS OF THE PATIENTS: Two young women (25 and 27 years old, respectively) presented with complaints compatible with a diagnosis of APN. However in both, fever was of high grade, persistent for several days in spite of antibiotic administration, and there was demonstrated worsening of the inflammatory biomarkers. A contrast-enhanced computed tomography (CECT) led to the diagnosis in both cases. DIAGNOSES: Contrast-enhanced computed tomography reveals the most sensitive and specific images of AFBN. This includes wedge-shaped lesions with decreased enhancement, which may be focal or multifocal. INTERVENTIONS INCLUDING PREVENTION AND LIFESTYLE: Antibiotic therapy for at least 3 weeks. OUTCOMES: Resolution of AFBN was obtained after 3 weeks of antibiotics. LESSONS LEARNED: Our 2 cases illustrate the importance of CECT imaging to confirm the diagnosis of AFBN. Interstitial bacterial inflammation may have a worse prognosis if not diagnosed early and efficiently treated. Unlike APN, the management of AFBN requires at least 3 weeks of antibiotics to prevent the development of renal scarring and renal abscess.

JUSTIFICATION: La pyélonéphrite aigüe focale (PNAF) a principalement été observée en pédiatrie. Il pourrait s'agir d'une affection sous-diagnostiquée chez les adultes puisque sa présentation clinique est similaire à la pyélonéphrite aigüe (PNA). PRÉSENTATION DES CAS: Nous présentons les cas de deux jeunes femmes (âgées respectivement de 25 et de 27 ans) qui présentaient des troubles compatibles avec une PNA. Cependant, dans les deux cas, la fièvre était élevée et a persisté plusieurs jours malgré l'administration d'antibiotiques. On a également observé une augmentation des biomarqueurs de l'inflammation. Un examen par CECT a mené au diagnostic de PNAF dans les deux cas. DIAGNOSTIC: La tomodensitométrie avec injection de contraste (CECT) révèle les images les plus sensibles et les plus spécifiques à la PNAF. Notamment les lésions cunéiformes avec intensification réduite pouvant être focale ou multifocale. INTERVENTIONS PRÉVENTION ET HABITUDES DE VIE: Un traitement antibiotique d'une durée de trois semaines. RÉSULTATS: La PNAF s'est résorbée après un traitement aux antibiotiques de trois semaines. ENSEIGNEMENTS TIRÉS: Nos deux cas illustrent l'importance de recourir à l'imagerie par CECT pour confirmer le diagnostic de la PNAF. Le pronostic de l'infection bactérienne interstitielle est susceptible de s'assombrir si celle-ci n'est pas diagnostiquée rapidement et traitée efficacement. Contrairement à la PNA, la prise en charge de la PNAF exige un traitement antibiotique d'au moins trois semaines afin de prévenir la fibrose rénale et la formation d'abcès rénaux.

Diagnosis of an Acute Lobar Nephronia in the Emergency Department Using POINT-OF-CARE Ultrasound.

BACKGROUND: Over the past decade, point-of-care ultrasound (POCUS) has been performed increasingly in pediatric emergency medicine for a variety of indications. POCUS is a focused, limited, goal-directed examination at the bedside performed and interpreted by a physician trained in POCUS with the purpose of answering a specific question. Applying POCUS for immediate evaluation of specific emergent complaints may allow for faster and safer management of ill patients in the pediatric emergency department (ED). CASE REPORT: A 5-year-old female presented to the pediatric ED with fever, vomiting, and back pain. Based on the real-time gray scale and color Doppler POCUS findings, a diagnosis of an acute lobar nephronia (ALN) was made by a pediatric emergency physician and the patient was admitted to the hospital before laboratory and urinalysis findings were resulted. This case report illustrates how POCUS and knowledge of the sonographic characteristics of an ALN were beneficial for shortening the time to decision for admission, rapidly ruling out hydronephrosis (which may have required other interventions), and conveying important information to the admitting team. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Performing a kidney POCUS and knowing the sonographic characteristics of an ALN can assist in its diagnosis, especially in patients where pyuria is absent. In addition, performing a kidney POCUS in patients with a suspected upper urinary tract infection may shorten the time to decision for admission and improve communication with the pediatric admitting resident regarding diagnosis and indication.

Acute focal bacterial nephritis in a cohort of hospitalized adult patients with acute pyelonephritis. Assessment of risk factors and a predictive model.

BACKGROUND: Acute focal bacterial nephritis (AFBN) is a complicated form of acute pyelonephritis (APN) characterized by single or multiple areas of localised infection in the kidney without liquefaction or abscess. Studies investigating AFBN in adults are scarce. AIM: The present study was aimed at evaluating the prevalence, associated factors, and presence of atypical clinical and radiological manifestations in adult AFBN patients. Also, we developed a clinical prediction model to evaluate the probability of AFBN in patients with APN. METHODS: The clinical records of 377 patients (mean age 54years, 74.0% females) admitted to a hospital over a 5-year period with APN were reviewed. RESULTS: A total of 57 cases of AFBN were radiologically identified (prevalence, 15.1%). Patients with AFBN were younger and displayed atypical manifestations more frequently than patients without AFBN; these included both clinical and radiological (pleural effusion, gallbladder wall thickening, fluid around the gallbladder, perirenal fluid, and ascites) manifestations. Patients with AFBN showed lower systolic blood pressure and needed more days of therapy to become afebrile, longer total duration of antibiotic therapy, and longer hospital stay than patients without AFBN. Contraceptive use was more frequent in patients with AFBN. A model based on five clinical variables showed good discrimination performance for the diagnosis of AFBN (Area under the curve, 0.77 (95% CI, 0.69-0.89)). CONCLUSIONS: Patients with AFBN frequently present with atypical clinical and radiological manifestations. Clinical presentation by means of a predictive model may predict the presence of AFBN. Patients with AFBN need more intensive therapy, which is followed by a favourable outcome.

Nefronia en pediatría: dentro del espectro de las infecciones urinarias. Serie clínica y revisión de la literatura / Nephronia in pediatrics: part of the spectrum of upper urinary tract infections. Clinical cases and review of the literature

Nephronia or focal acute nephritis corresponds to a localized inflammatory non-liquefactive kidney infection which may involve parenchyma of one or more renal lobes. It has been suggested that nephronia is part of the spectrum of upper urinary tract infections between acute pyelonephritis and renal abscess. It is associated with a prolonged clinical course, higher levels of inflammatory markers and an increased risk of renal scarring, compared to pyelonephritis. Ultrasound plays a useful role. Nephronia is an under-diagnosed condition, thus, clinical suspicion is important for early diagnosis and appropriate treatment. We present three paediatric cases, and a review of the literature.

La nefronia o nefritis focal aguda es una inflamación renal de etiología bacteriana sin licuefacción que típicamente involucra el parénquima de uno o más lóbulos renales. Dentro del espectro de las infecciones del tracto urinario, se ha planteado que podría ser una entidad intermedia entre la pielonefritis aguda y el absceso renal. Se asocia a un curso clínico más prolongado, mayores marcadores inflamatorios y mayor riesgo de cicatrices renales, al compararla con la pielonefritis. La ecografía renal juega un rol útil en el diagnóstico. Es una entidad subdiagnosticada; por lo que su sospecha es relevante para un diagnóstico oportuno y un tratamiento adecuado. Se presentan tres casos clínicos pediátricos y una revisión del tema.

Acute lobar nephronia in renal transplant: Gallium-67 scintigraphy for diagnosis and therapy monitoring.

A 33 years old female patient with chronic renal transplant rejection proved by MAG3, ultrasound and graft biopsy presented with abdominal pain and fever. Part of her work up included gallium-67 scan which revealed diffuse abnormal graft uptake with multifocal areas of marked uptake. Findings were interpreted as acute lobar nephronia. Repeat gallium scan two weeks after intravenous antibiotic therapy showed significant response reflected by resolution of most of focal areas of increased uptake which was parallel to clinical improvement.

Comparison of acute lobar nephronia and acute pyelonephritis in children: a single-center clinical analysis in southern taiwan.

BACKGROUND: Patients with acute lobar nephronia (ALN) require a longer duration of antimicrobial treatment than those with acute pyelonephritis (APN), and ALN is associated with renal scarring. The aim of this study was to provide an understanding of ALN by comparing the clinical features of pediatric patients with ALN and APN. METHODS: We enrolled all of the patients with ALN (confirmed by computed tomography) admitted to our hospital from 1999 to 2012 in the ALN group. In addition, each patient diagnosed with APN who was matched for sex, age, and admission date to each ALN patient was enrolled in the APN group. The medical charts of patients in these two groups were retrospectively reviewed and analyzed for comparison. RESULTS: The fever duration after hospitalization in the ALN group and the APN group were 4.85 ± 2.33 days and 2.30 ± 1.47 days respectively. The microbiological distributions and the majority of susceptibilities were similar in the ALN and APN groups. The majority of clinical manifestations are nonspecific and unreliable for the differentiation of ALN and APN. The patients with ALN were febrile for longer after antimicrobial treatment, had more nausea/vomiting symptoms, higher neutrophil count, bandemia, and C-reactive protein (CRP) levels, and lower platelet count (all p < 0.05). In multivariate analysis, initial CRP levels, nausea/vomiting symptoms, and fever duration after admission were independent variables with statistical significance to predict ALN. Severe nephromegaly occurred significantly more in the ALN group than in the APN group (p = 0.022). CONCLUSION: The majority of clinical manifestations, laboratory findings, and microbiological features are similar between patients with ALN and APN. Clinicians should keep a high index of suspicion regarding ALN, particularly for those with ultrasonographic nephromegaly, initial higher CRP, nausea/vomiting, and fever for > 5 days after antimicrobial treatment.

Acute lobar nephronia: a case report and literature review.

BACKGROUND: Patients with fever, vomiting, and abdominal pain commonly present to the emergency department, often generating a broad differential diagnosis. We describe the first reported case in the emergency medicine literature of acute lobar nephronia (ALN). OBJECTIVES: To describe the presentation, evaluation, and management of acute lobar nephronia. CASE REPORT: A healthy 27-year-old woman presented after 18 h of fever to 39.94°C (103.9°F), nausea, vomiting, and severe right-sided abdominal pain. Despite a normal urinalysis, a contrasted computed tomography scan of the abdomen and pelvis demonstrated right perinephric stranding, which was initially interpreted as pyelonephritis. A staff over-read the following day by a radiology body specialist confirmed "likely developing abscess," consistent with the diagnosis of acute lobar nephronia. CONCLUSION: A normal urinalysis may move clinicians to dismiss a nephrogenic or urologic process. ALN is considered a midpoint in the spectrum of upper urinary tract infections between acute pyelonephritis and intrarenal abscess. Diagnosis may be difficult, and inpatient management, sometimes prolonged, is the norm.

Child with acute lobar nephronia.

A five-year-old girl child presented to us with a history of two weeks high grade fever treated outside with intensive antibiotic therapy for an ultrasound abdomen finding of hypoechoic lesion in the midpole of the left kidney. As fever and sonographic findings persisted, a CT abdomen was done, which showed features of lobar nephronia but reported as Wilm's tumor. Child underwent open biopsy and the diagnosis of lobar nephronia was confirmed. Child was continued on antibiotics and fever and sonographic findings improved.

Nefritis aguda focal: caso clínico / Focal acute nephritis: a case report

Focal acute nephritis (FAN) or acute lobar nephronia is a rare clinical picture characterized by an infection localized in the kidney, with an inflammatory mass without liquefaction. Of variable clinical manifestations, diagnosis is achieved through CT scanning. Histologically, unlike acute pyelonephritis, it does not present a diffuse infíltrate. Objective: Case report of FAN in a pediatric patient. Case Report: Ten year old male complaining of abdominal pain, presents painful percussion in the right lumbar fossa. Urinary analysis and culture were negative, renal sonogram was negative. Abdominal CT sean showed múltiple hypodense renal foci. He responded well to cephotaxim, being discharged in the third day of hospitalization with completion of treatment as outpatient. Differential diagnosis with Acute Pyelonephritis is very important, as it requires controlled and opportune treatment to prevent renal absceses. Diagnosis of this pathology must be pursued despite a normal UA.

La nefritis aguda focal o nefronia lobar aguda constituye un cuadro poco común caracterizado por una infección localizada en el riñon, la que corresponde a una masa inflamatoria sin licuefacción. Posee una clínica variable, siendo la tomograña computada (TAC) la prueba más sensible y específica para el diagnóstico de esta enfermedad. Esta patología se diferencia histológicamente de la pielonefritis aguda por no presentar un infiltrado inflamatorio difuso. Objetivo: presentar un caso de nefronia aguda multifocal en un paciente pediátrico. Caso clínico: Escolar de 10 años que consultó por dolor abdominal, al examen destacaba la presencia de percusión dolorosa en fosa lumbar. Los exámenes de orina y urocultivo fueron negativos. Al ingreso no se detectó cambios renales ecográficamente evidenciables. Se realizó un TAC de abdomen que mostraba múltiples focos renales hipodensos. Respondió favorablemente a terapia antibiótica con cefotaxima siendo dado de alta al tercer día, completando terapia en forma ambulatoria. La diferenciación de este cuadro de otros procesos renales como la pielonefritis aguda (PNA) es muy importante, ya que precisa un tratamiento oportuno y controlado por el riesgo de evolucionar a absceso renal. El diagnóstico de esta patología debe ser buscado a pesar de contar con exámenes de orina negativos.

Clinical Characteristics and Renal Outcomes of Acute Focal Bacterial Nephritis in Children

PURPOSE: This study was performed to elucidate the clinical pictures of acute focal bacterial nephritis(nephronia) in children. METHODS: We reviewed 9 children with nephronia diagnosed by ultrasonography or computed tomography of kidneys from September 1994 to August 2004. RESULTS: The overall male to female ratio was 2:1, and the age distribution ranged from 0.1 to 6 years(mean 2.8+/-2.2). The cardinal symptoms were fever, chills, abdominal pain and dysuria/frequency. The initial leukocyte count was 21,000+/-5,600/uL; ESR, 60+/-23 mm/hr; CRP, 17+/-10 mg/dl. Pyuria was noted in every patient and persisted for 10.5+/-7.8 days after antimicrobial treatment. Abdominal sonography demonstrated focal lesion of ill-defined margin and low echogenicity in 5 of 9 patients(55.6%), while computed tomography revealed nonenhancing low density area in all patients(100%). Three of 9 patients(33.3%) had vesicoureteral reflux, greater than grade III. The initial (99m)Tc-DMSA scan showed one or multiple cortical defects in every patient, and improvements were noted in 2(33.3%) of 6 patients who received follow up scan after 4 months. Intravenous antibiotics was given in every patient under admission. Total febrile period was 11.8+/-6.3 days(pre-admission, 4.0+/-3.0; post-admission, 7.8+/-5.5 days) and the patients needed hospitalization for 17.2+/-8.1 days. CONCLUSION: For the early diagnosis of 'acute focal bacterial nephritis' we should perform renal computed tomography first rather than ultrasonography, when the child has toxic symptoms and severe inflammatory responses in blood and urine.

Focal Bacterial Nephritis (Lobar Nephronia) in a Four-Month Old Boy

Acute lobar nephronia is a focal form of acute bacterial nephritis, affecting one or more of the renal lobules. Nephronia is being diagnosed more frequently in accordance with the advancing imaging techniques of urinary tract. We report a case of acute nephronia in a 4 month old boy who presented persisting urinary tract infection after intial antibiotic treatment. Ultrasonography and computerized tomography showed round wedge-shaped, non-enhancing mass in right kidney. Gallium scan also revealed the lesion in the right kidney. This lesion resolved completely on one month follow up examinations.