Post-streptococcal glomerulonephritis in Sydney: a 16-year retrospective review

A 6-year review of acute post-streptococcal glomerulonephritis at a public children's hospital in Cape Town, South Africa

BACKGROUND

Acute post-streptococcal glomerulonephritis (APSGN) is the most common cause of acute nephritis in children globally and, in some cases, may be associated with progressive kidney injury and failure, cumulating in the need for long-term dialysis and/or kidney transplantation.

METHODS

Our retrospective study describes the occurrence of APSGN among children (< 14 years) admitted to a tertiary children's hospital in Cape Town, South Africa, from January 2015 to December 2020.

RESULTS

Of 161 children who presented with acute nephritis (haematuria, oedema, oliguria, and hypertension), 100 met the inclusion criteria. Demographic, clinical features, laboratory findings, management, and outcome data were collected. APSGN was defined by the clinical presentation of at least two clinical signs of acute nephritis, and low serum complement 3 (C3) level or evidence of a recent streptococcal infection. Most cases of APSGN were associated with streptococcal skin infections: 55/100 (55%); 10/100 (10%) children presented with hypertensive seizures; C3 levels were low in 86/92 (93.5%) children; 94/94 (100%) children had elevated anti-deoxyribonuclease-B (anti-DNase-B) levels; and 80/94 (85%) also had elevated anti-streptolysin O titre (ASOT) at presentation. Eleven (11%) children had a percutaneous kidney biopsy; 4/11 (36%) showed histological features of post-infectious nephritis, and 7/11(64%) also had crescentic glomerulonephritis with immune complex deposits. Sixty-two (62%) children confirmed recovered, and five (5%) progressed to kidney failure, but 29 presumed recovered as they did not return for follow-up to our institution.

CONCLUSIONS

Childhood APSGN remains an important health problem in South Africa (SA) with favourable outcomes in most, apart from those with crescentic glomerulonephritis who progressed to kidney failure.

Acute Post-streptococcal Glomerulonephritis in a Pediatric Population: A Five-Year Retrospective Study

INTRODUCTION

Post-streptococcal glomerulonephritis is a kidney disease that occurs after infection with a certain strain of streptococcal bacteria. It has a high hospitalization rate, especially in developing countries. It is characterized by the sudden appearance of edema, hematuria, proteinuria, and hypertension. The objective of this retrospective descriptive study conducted at James L. Gordon Memorial Hospital in Olongapo, Zambales, Philippines, is to analyze the demographic distribution, clinical presentation, complication, and outcome of acute post-streptococcal glomerulonephritis (APSGN) in a pediatric population.  Methods: A retrospective descriptive study was done in patients (below 18 years of age) admitted with the diagnosis of post-streptococcal glomerulonephritis during a five-year period in the pediatric ward of a tertiary hospital in the Philippines. All patients underwent detailed clinical history and examination and were closely monitored during treatment. The course of disease progression was closely monitored and recorded.

RESULTS

Seventy-seven children were treated for APSGN with a mean age of 7.8 years and with standard deviation of 3.85. Edema and gross hematuria were noted in 53 (68.8%) and 24 (31.1%) cases, respectively. Hypertension was present in 54 patients (70.1%). Among those 54 patients, 49 (63.6%) patients developed acute renal injury (based on normal creatinine for age), three cases (3.8%) had pleural effusion, and two patients (2.5%) developed hypertensive encephalopathy. All patients underwent KUB (kidneys, ureters, and bladder) ultrasound, among which 13 (16.88%) had diffuse parenchymal swelling which improved and eventually were discharged. Increased blood urea nitrogen (BUN) was noted in 60-65% of patients. Hypoalbuminemia and lower hemoglobin were also quite common. There was no mortality during treatment and hospital stay.

CONCLUSIONS

APSGN remains one of the most common causes of glomerulonephritis in the region. Edema, hypertension, and hematuria were the most common presenting features. Early identification and comprehensive monitoring and management are required to prevent morbidity and mortality. The prognosis is generally good if early treatment is done.

Risk factors associated with short- and long-term kidney injury in children with post infectious glomerulonephritis

BACKGROUND

Post infectious glomerulonephritis (PIGN) is the most common form of acute glomerulonephritis in children. The objective of this study was to evaluate the risk factors for kidney injury in children with PIGN referred to a tertiary care center.

METHODS

This was a retrospective cohort study. The primary outcome was acute kidney injury (AKI) at initial presentation; secondary outcome was composite kidney injury, defined as reduced estimated glomerular filtration rate (eGFR), proteinuria, or hypertension at last follow-up. Binary logistic regression defined risk factors associated with the primary and secondary outcomes.

RESULTS

We identified 125 PIGN cases with a mean age of 8.3±3.5 years at presentation and 252 ± 501 days of follow-up. Sixty-six percent (79/119) presented with AKI and 57% (71/125) were admitted to hospital. Shorter time to seeing a nephrologist (OR 6.7, 95%CI 1.8-24.6), nadir C3 < 0.12 g/L (OR 10.2, 95%CI 1.9-53.7), starting an antihypertensive medication (OR 7.6, 95%CI 1.8-31.3), and nephrotic range proteinuria (OR 3.8, 95%CI 1.2-12.4) were independent risk factors for AKI when adjusted for each other. At last follow-up 35% (44/125) of the cohort had the composite outcome, with older age at presentation (OR 1.2, 95%CI 1.04-1.4) and nadir C3 < 0.17 g/L (OR 2.6, 95%CI 1.04-6.7) being independent risk factors when adjusted for AKI.

CONCLUSION

PIGN is an important cause of AKI in children and adolescents. The severity of initial illness is associated with the extent of kidney injury in both the short- and longer-term. Findings will help identify cases requiring lengthier surveillance. A higher resolution version of the Graphical abstract is available as Supplementary information.

Predictors of rapidly progressive glomerulonephritis in acute poststreptococcal glomerulonephritis

BACKGROUND

Acute post-streptococcal glomerulonephritis (APSGN) is an immune-mediated inflammatory respsonse in the kidneys caused by nephritogenic strains of group A β-hemolytic streptococcus (GAS). The present study aimed to present a large patient cohort of APSGN patients to determine the factors that can be used for predicting the prognosis and progression to rapidly progressive glomerulonephritis (RPGN).

METHODS

The study included 153 children with APSGN that were seen between January 2010 and January 2022. Inclusion criteria were age 1-18 years and follow-up of ≥ 1 years. Patients with a diagnosis that could not be clearly proven clinically or via biopsy and with prior clinical or histological evidence of underlying kidney disease or chronic kidney disease (CKD) were excluded from the study.

RESULTS

Mean age was 7.36 ± 2.92 years, and 30.7% of the group was female. Among the 153 patients, 19 (12.4%) progressed to RPGN. The complement factor 3 and albumin levels were significantly low in the patients who had RPGN (P = 0.019). Inflammatory parameters, such as C-reactive protein (CRP), platelet-to-lymphocyte ratio, CRP/albumin ratio, and the erythrocyte sedimentation rate level at presentation were significantly higher in the patients with RPGN (P < 0.05). Additionally, there was a significant correlation between nephrotic range proteinuria and the course of RPGN (P = 0.024).

CONCLUSIONS

We suggest the possibility that RPGN can be predicted in APSGN with clinical and laboratory findings. A higher resolution version of the Graphical abstract is available as Supplementary information.

Standardization of Epidemiological Surveillance of Acute Poststreptococcal Glomerulonephritis

Acute poststreptococcal glomerulonephritis (APSGN) is an immune complex-induced glomerulonephritis that develops as a sequela of streptococcal infections. This article provides guidelines for the surveillance of APSGN due to group A Streptococcus (Strep A). The primary objectives of APSGN surveillance are to monitor trends in age- and sex-specific incidence, describe the demographic and clinical characteristics of patients with APSGN, document accompanying risk factors, then monitor trends in frequency of complications, illness duration, hospitalization rates, and mortality.

This document provides surveillance case definitions for APSGN, including clinical and subclinical APSGN based on clinical and laboratory evidence. It also details case classifications that can be used to differentiate between confirmed and probable cases, and it discusses the current investigations used to provide evidence of antecedent Strep A infection.

The type of surveillance recommended depends on the burden of APSGN in the community and the objectives of surveillance. Strategies for minimal surveillance and enhanced surveillance of APSGN are provided. Furthermore, a discussion covers the surveillance population and additional APSGN-specific surveillance considerations such as contact testing, active follow up of cases and contacts, frequency of reporting, surveillance visits, period of surveillance, and community engagement. Finally, the document presents core data elements to be collected on case report forms, along with guidance for documenting the course and severity of APSGN.

Intolerable Burden of Impetigo in Endemic Settings: A Review of the Current State of Play and Future Directions for Alternative Treatments

Impetigo (school sores) is a common superficial bacterial skin infection affecting around 162 million children worldwide, with the highest burden in Australian Aboriginal children. While impetigo itself is treatable, if left untreated, it can lead to life-threatening conditions, such as chronic heart and kidney diseases. Topical antibiotics are often considered the treatment of choice for impetigo, but the clinical efficacy of these treatments is declining at an alarming rate due to the rapid emergence and spread of resistant bacteria. In remote settings in Australia, topical antibiotics are no longer used for impetigo due to the troubling rise of antimicrobial resistance, demanding the use of oral and injectable antibiotic therapies. However, widespread use of these agents not only contributes to existing resistance, but also associated with adverse consequences for individuals and communities. These underscore the urgent need to reinvigorate the antibiotic discovery and alternative impetigo therapies in these settings. This review discusses the current impetigo treatment challenges in endemic settings in Australia and explores potential alternative antimicrobial therapies. The goals are to promote intensified research programs to facilitate effective use of currently available treatments, as well as developing new alternatives for impetigo.

Clinical characteristics of acute glomerulonephritis with presentation of nephrotic syndrome at onset in children

BACKGROUND

Acute glomerulonephritis (AGN) is a common disease in children, which places a huge burden on developing countries. The prognosis of it may not always be good. However, the clinical characteristics of AGN with nephrotic syndrome (NS) at onset have not been fully clarified.

METHODS

One hundred and thirteen cases were analyzed retrospectively. Clinical data, pathological results and prognosis between AGN with NS (AGN-NS) and AGN without NS (AGN-no-NS) were compared.

RESULTS

Twenty (17.7%) of 113 patients were AGN-NS. The patients with AGN-NS were more likely to have hypertension (55.0% vs. 25.8%) and acute kidney injury (AKI) (50.0% vs. 17.2%). AKI was significantly related to the manifestation of AGN-NS in children (OR = 3.812, P = 0.040). Compared with the AGN-no-NS, the immunosuppressive treatments were more common in AGN-NS. A more severe pathological grade was significantly related to lower C3 fraction, estimated glomerular filtration rate (eGFR), and AKI, but not to the performance of AGN-NS. There was no difference in prognosis between the two groups.

CONCLUSIONS

AKI was significantly associated with AGN-NS. The prognosis of AGN-NS and AGN-no-NS in our study was almost good. Given the fact that AGN-NS patients are more likely to use immunosuppressive therapy, the long-term outcome of AGN-NS warrants further research.

Acute post-streptococcal glomerulonephritis in Central Australia

OBJECTIVE

To determine the incidence, clinical presentation and progress of acute post-streptococcal glomerulonephritis in Central Australia.

DESIGN

Retrospective observational analysis.

SETTING

Paediatric inpatient admission at Alice Springs Hospital.

PARTICIPANTS

Patients admitted to Alice Springs Hospital under 14 years of age meeting diagnostic criteria for acute post-streptococcal glomerulonephritis between January 2010 and December 2014.

MAIN OUTCOME MEASURES

Incidence of acute post-streptococcal glomerulonephritis in central Australia. Biochemical abnormalities associated with acute post-streptococcal glomerulonephritis. Co-occuring conditions.

RESULTS

Sixty-nine out of the 174 cases reviewed were identified as having either acute post-streptococcal glomerulonephritis (63) or probable acute post-streptococcal glomerulonephritis (6). We calculate the incidence of APSGN admission to be higher than previously reported and the highest reported incidence globally in children. Clinical evidence of skin infection was frequently documented. Co-occurring infections were common, including scabies/head lice, urinary tract infection and pneumonia. Fifty-three patients showed biochemical evidence of acute kidney injury.

CONCLUSIONS

Aboriginal children in Central Australia have the highest incidence of acute post-streptococcal glomerulonephritis reported worldwide. Urgent action is required to improve housing and reduce overcrowding in Central Australian towns and communities to reduce the burden of disease of skin infection and Group A Streptococcus related diseases. Without effective change in living conditions, it is unlikely that there will be a significant change in the morbidity related to these conditions.

Skin infections in Australian Aboriginal children: a narrative review

Impetigo, scabies, cellulitis and abscesses are common in Australian Aboriginal children. These conditions adversely affect wellbeing and are associated with serious long term sequelae, including invasive infection and post‐infectious complications, such as acute post‐streptococcal glomerulonephritis and acute rheumatic fever, which occurs at the highest documented rates in the world in remote Aboriginal communities.

Observational research in remote communities in northern Australia has demonstrated a high concurrent burden of scabies and impetigo and their post‐infectious complications.

Few data are available for other Australian states, especially for urban Aboriginal children; however, nationwide hospital data indicate that the disparity between Aboriginal and non‐Aboriginal children in skin infection prevalence also exists in urban settings.

The Australian National Healthy Skin Guideline summarises evidence‐based treatment of impetigo, scabies and fungal infections in high burden settings such as remote Aboriginal communities. It recommends systemic antibiotics for children with impetigo, and either topical permethrin or oral ivermectin (second line) for the individual and their contacts as equally efficacious treatments for scabies. β‐Lactams are the treatment of choice and trimethoprim–sulfamethoxazole and clindamycin are effective alternatives for treatment of paediatric cellulitis. Abscesses require incision and drainage and a 5‐day course of trimethoprim–sulfamethoxazole or clindamycin.

Addressing normalisation of skin infections and the social determinants of skin health are key challenges for the clinician. Research is underway on community‐wide skin health programs and the role for mass drug administration which will guide future management of these common, treatable diseases.

A rare adult case of poststreptococcal acute glomerulonephritis with a retropharyngeal abscess

Retropharyngeal abscess is an infection involving the retropharyngeal space which is posterior to the pharynx and oesophagus, and it results as a complication of a primary infection elsewhere in the head and neck including the nasopharynx, paranasal sinuses, or middle ear, which drain lymph to the retropharyngeal lymph nodes. Their lymph nodes are prominent in children and atrophy with age. Therefore, retropharyngeal abscess is most frequently encountered in children, with 75% of cases occurring before the age of 5 years, and often in the first year of life. We experienced a rare adult case of poststreptococcal acute glomerulonephritis with a retropharyngeal abscess, and conservative therapy ameliorated them. According to past reports, only one child with a retropharyngeal abscess and poststreptococcal acute glomerulonephritis has been presented at a conference to date; this is the first adult case of poststreptococcal acute glomerulonephritis with a retropharyngeal abscess. Retropharyngeal abscess can be fatal including airway compression, so it is important to remember retropharyngeal abscess in a case of poststreptococcal acute glomerulonephritis with severe symptoms of neck.

Renal outcome and risk factors for end-stage renal disease in pediatric rapidly progressive glomerulonephritis

BACKGROUND

Rapidly progressive glomerulonephritis (RPGN), defined as acute nephritic syndrome with dramatic loss of renal function within a few months, is associated with crescentic glomerulonephritis (CresGN), which requires ≥50% crescents on pathology. The disease characteristics and renal outcome in children with RPGN, however, will differ according to the percentage of crescents.

METHODS

To evaluate the renal outcomes and factors associated with end-stage renal disease (ESRD), this retrospective cohort study assessed children aged ≤15 years with RPGN at a tertiary medical center.

RESULTS

Of 67 patients with RPGN, 32 (47.8%) were male; mean age was 10.6 ± 3.0 years; median follow up was 1.1 years (range, 0.02-9.17 years) and 24 (35.8%) progressed to ESRD. Post-infectious glomerulonephritis was the most frequent cause of RPGN (50.7%). The incidence of ESRD was significantly higher in patients with ≥50% than <50% crescents (57.9% vs 28.6%, P = 0.029). On Cox regression analysis, disease etiology, serum creatinine >3 mg/dL, need for acute dialysis, ≥80% crescents and ≥20% tubular atrophy and interstitial fibrosis (TA/IF) were associated with ESRD. On multivariate analysis, need for acute dialysis (HR, 2.8; 95% CI: 1.1-7.3, P = 0.041) and ≥20% TA/IF (HR, 4.8; 95% CI: 1.4-16.1, P = 0.011) were independent risk factors for the development of ESRD.

CONCLUSIONS

Approximately one-third of children with RPGN developed ESRD; and need for acute dialysis and TA/IF ≥20% were independent risk factors for ESRD.

Post-infectious group A streptococcal autoimmune syndromes and the heart

There is a pressing need to reduce the high global disease burden of rheumatic heart disease (RHD) and its harbinger, acute rheumatic fever (ARF). ARF is a classical example of an autoimmune syndrome and is of particular immunological interest because it follows a known antecedent infection with group A streptococcus (GAS). However, the poorly understood immunopathology of these post-infectious diseases means that, compared to much progress in other immune-mediated diseases, we still lack useful biomarkers, new therapies or an effective vaccine in ARF and RHD. Here, we summarise recent literature on the complex interaction between GAS and the human host that culminates in ARF and the subsequent development of RHD. We contrast ARF with other post-infectious streptococcal immune syndromes - post-streptococcal glomerulonephritis (PSGN) and the still controversial paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), in order to highlight the potential significance of variations in the host immune response to GAS. We discuss a model for the pathogenesis of ARF and RHD in terms of current immunological concepts and the potential for application of in depth "omics" technologies to these ancient scourges.

Poststreptococcal glomerulonephritis in a patient with essential thrombocytosis

In addition to being the main cause of glomerulonephritis in children, poststreptococcal glomerulonephritis (PSGN) has recently been shown in older patients, especially those with malignancy or diabetes mellitus. The pathogenesis of PSGN has been ascribed to activation of complement 3 (C3) of the alternative complement cascade which, along with immunoglobulin (Ig) G and IgM deposits, is observed in renal tissue. Our aim here is to discuss the probable causes of PSGN developing with isolated IgM deposition in a 52-year-old patient with essential thrombocytosis followed-up over the previous 3.5 years. These characteristics make our case the first to be reported in the literature.

How to use antistreptolysin O titre

Group A streptococcus (GAS) is the cause of a wide range of acute suppurative and, following a latent period, non-suppurative diseases such as rheumatic fever and poststreptococcal glomerulonephritis. Diagnosis of the latter group requires evidence of preceding GAS infection. The bacteria produce a range of extracellular antigens, including streptolysin O, which induce an antibody response in the host. A rise in antistreptolysin O titre (ASOT) is indicative of preceding GAS infection. In clinical practice, often only a single ASOT measurement is available and its timing in relation to a possible GAS infection is unknown. Interpretation of the result in this context is liable to misdiagnosis. In order to optimise diagnosis of preceding GAS infection, at least two sequential ASOT measurements, together with simultaneous assay for anti-DNase B, a second antistreptococcal antibody, is recommended.

[Acute postinfectious glomerulonephritis]

Acute postinfectious glomerulonephritis are defined by an acute nonsuppurative inflammatory insult predominantly glomerular. Its current incidence is uncertain because of the frequency of subclinical forms. The most common infectious agent involved is beta hemolytic streptococcus group A. Acute postinfectious glomerulonephritis is uncommon in adults, and its incidence is progressively declining in developed countries. Humoral immunity plays a key role in the pathogenesis of kidney damage. Complement activation by the alternative pathway is the dominant mechanism, but a third way (lectin pathway) has been recently identified. The classic clinical presentation is sudden onset of acute nephritic syndrome after a free interval from a streptococcal infection. Treatment is essentially symptomatic and prevention is possible through improved hygiene and early treatment of infections.

Acute post-streptococcal glomerulonephritis in the Northern Territory of Australia: a review of 16 years data and comparison with the literature

Data relating to acute post-streptococcal glomerulonephritis (APSGN) from the notifiable diseases surveillance system in the Northern Territory of Australia was extracted and analyzed. Isolates of Streptococcus pyogenes from confirmed cases were emm sequence typed. From 1991 to July 2008, there were 415 confirmed cases and 23 probable cases of APSGN notified. Four hundred fifteen (94.7%) of these were Indigenous Australians and 428 (97.7%) were people living in remote or very remote locations. The median age of cases was 7 years (range 0-54). The incidence of confirmed cases was 12.5/100,000 person-years, with an incidence in Indigenous Australian children younger than 15 years of age of 94.3 cases/100,000 person-years. The overall rate ratio of confirmed cases in Indigenous Australians to non-Indigenous Australians was 53.6 (95% confidence interval 32.6-94.8). Outbreaks of disease across multiple communities occurred in 1995 (N = 68), 2000 (N = 55), and 2005 (N = 87 [confirmed cases]). Various emm types of S. pyogenes were isolated from cases of APSGN including some types not previously recognized to be nephritogenic. The widespread outbreak in 2005 was caused by emm55.0 S. pyogenes. Acute post-streptococcal glomerulonephritis continues to occur in remote Indigenous communities in Australia at rates comparable to or higher than those estimated in developing countries. Improvements in preventative and outbreak control strategies are needed.

The burden of kidney disease in indigenous children of Australia and New Zealand, epidemiology, antecedent factors and progression to chronic kidney disease

AIMS

To review and present the most important issues related to kidney disease in Aboriginal, Torres Strait Islander, Maori and Pacific Islander children from Australia and New Zealand.

METHODS

A review of medical literature about: 1. incidence of kidney disease in Indigenous children in Australia and New Zealand, especially where rates are different from the general populations, 2. factors in early life which increase risk for chronic kidney disease in adult life, and 3. early identification and primary and secondary interventions in childhood which may prevent chronic kidney disease in adults.

RESULTS

Kidney diseases, both acute and chronic are more common in Maori, Pacific Islander, Australian Aboriginal and Torres Strait Islander people. The reasons are multiple and include genetic, environmental and socio-economic factors. In childhood post streptococcal glomerulonephritis, haemolytic uraemic syndrome, renal stones and acute kidney injury all occur at higher frequency in at least some of the Indigenous populations. Chronic kidney disease CKD occurs more commonly, and at a younger age in Indigenous than non Indigenous people. Factors involved may include reduced nephron endowment at birth, and subsequent insults including nephritis, obesity, and early onset type 2 diabetes, as well as underlying socioeconomic and environmental determinants.

CONCLUSION

A lifecourse understanding allows one to conceptualise multiple risk factors and target interventions.

Acute post-streptococcal glomerulonephritis in children of French Polynesia: a 3-year retrospective study

The aim of this study was to define the current demographic, clinical and prognostic characteristics of acute post-streptococcal glomerulonephritis (APSGN) in French Polynesia and to compare these features with those of other populations. Fifty children, all of whom were <15 years old and had been admitted to the Territorial Hospital of Papeete for APSGN between January 2005 and December 2007, were retrospectively enrolled in the study. Diagnostic criteria were microscopic or macroscopic haematuria, decreased C3 fraction of the complement and evidence of recent streptococcal infection. The annual incidence was 18 cases per 100,000 children <15 years of age in 2007. Most of the children (98%) enrolled in the study were of Polynesian ethnic origin, 27 were male (54%), and the average age at presentation was 6.7 years. Signs of previous respiratory infections were clearly evident in 40% of the children. Most of the patients presented during the rainy season, correlating with the relatively high incidence of skin infections at this time. The majority of patients had proteinuria (98%), with 25% having proteinuria in the nephrotic range (proteinuria/urinary creatinine >3 g/g). The presentation was severe in 22% of the children (congestive cardiac failure, severe hypertension and/or encephalopathy), and renal failure was an initial presenting symptom in 43.7%. The C3 fraction was lower in severe presentations, but the type of haematuria, level of proteinuria and inflammatory syndrome were not correlated with immediate severe forms or with initial renal failure. Haematuria resolved in a mean of 7.7 months and proteinuria in a mean of 3.9 months. None of the children had hypocomplementemia for more than 8 weeks. Acute post-streptococcal glomerulonephritis is endemic among French Polynesians, and they can be considered to be a high-risk population. Despite a high incidence of skin infections, however, the predominance of respiratory infections potentially indicates that French Polynesia is on the way to become a low-incidence area. Systematic detection and treatment of group A Streptococcus should be intensified.

Glomerulonephritis and managing the risks of chronic renal disease

The rising global burden of chronic renal disease, the high cost of providing renal replacement therapies, and renal disease also being a risk factor for cardiovascular disease is increasing focus on renal disease prevention. This article focuses on the aspects of renal disease (specifically poststreptococcal glomerulonephritis [PSGN] and chronic kidney disease [CKD]) in Indigenous populations in Australia, New Zealand, Canada, and the United States that diverge from those typically seen in the general population of those countries. The spectrum of renal and many other diseases seen in Indigenous people in developed countries is similar to that seen in developing countries. Diseases like PSGN that have largely disappeared in developed countries still occur frequently in Indigenous people. CKD during the childhood years is due to congenital anomalies of the kidney and urinary tract in up to 70% of cases and occurs later in polycystic kidney disease and childhood-onset diabetes. Several risk factors for CKD in adulthood are already present in childhood.

Elevated anti-streptococcal antibodies in patients with recent narcolepsy onset

STUDY OBJECTIVES

Narcolepsy-cataplexy has long been thought to have an autoimmune origin. Although susceptibility to narcolepsy, like many autoimmune conditions, is largely genetically determined, environmental factors are involved based on the high discordance rate (approximately 75%) of monozygotic twins. This study evaluated whether Streptococcus pyogenes and Helicobacter pylori infections are triggers for narcolepsy.

DESIGN

Retrospective, case-control.

SETTING

Sleep centers of general hospitals.

PARTICIPANTS

200 patients with narcolepsy/hypocretin deficiency, with a primary focus on recent onset cases and 200 age-matched healthy controls. All patients were DQB1*0602 positive with low CSF hypocretin-1 or had clear-cut cataplexy.

MEASUREMENTS AND RESULTS

Participants were tested for markers of immune response to beta hemolytic streptococcus (anti-streptolysin O [ASO]; anti DNAse B [ADB]) and Helicobacter pylori [Anti Hp IgG], two bacterial infections known to trigger autoimmunity. A general inflammatory marker, C-reactive protein (CRP), was also studied. When compared to controls, ASO and ADB titers were highest close to narcolepsy onset, and decreased with disease duration. For example, ASO > or = 200 IU (ADB > or = 480 IU) were found in 51% (45%) of 67 patients within 3 years of onset, compared to 19% (17%) of 67 age matched controls (OR = 4.3 [OR = 4.1], P < 0.0005) or 20% (15%) of 69 patients with long-standing disease (OR = 4.0 [OR = 4.8], P < 0.0005]. CRP (mean values) and Anti Hp IgG (% positive) did not differ from controls.

CONCLUSIONS

Streptococcal infections are probably a significant environmental trigger for narcolepsy.

High burden of impetigo and scabies in a tropical country

Background

Impetigo and scabies are endemic diseases in many tropical countries; however the epidemiology of these diseases is poorly understood in many areas, particularly in the Pacific.

Methodology/Principal Findings

We conducted three epidemiological studies in 2006 and 2007 to determine the burden of disease due to impetigo and scabies in children in Fiji using simple and easily reproducible methodology. Two studies were performed in primary school children (one study was a cross-sectional study and the other a prospective cohort study over ten months) and one study was performed in infants (cross-sectional). The prevalence of active impetigo was 25.6% (95% CI 24.1–27.1) in primary school children and 12.2% (95% CI 9.3–15.6) in infants. The prevalence of scabies was 18.5% (95% CI 17.2–19.8) in primary school children and 14.0% (95% CI 10.8–17.2) in infants. The incidence density of active impetigo, group A streptococcal (GAS) impetigo, Staphylococcus aureus impetigo and scabies was 122, 80, 64 and 51 cases per 100 child-years respectively. Impetigo was strongly associated with scabies infestation (odds ratio, OR, 2.4, 95% CI 1.6–3.7) and was more common in Indigenous Fijian children when compared with children of other ethnicities (OR 3.6, 95% CI 2.7–4.7). The majority of cases of active impetigo in the children in our study were caused by GAS. S. aureus was also a common cause (57.4% in school aged children and 69% in infants).

Conclusions/Significance

These data suggest that the impetigo and scabies disease burden in children in Fiji has been underestimated, and possibly other tropical developing countries in the Pacific. These diseases are more than benign nuisance diseases and consideration needs to be given to expanded public health initiatives to improve their control.

Scabies and impetigo are often thought of as nuisance diseases, but have the potential to cause a great deal of morbidity and even mortality if infection becomes complicated. Accurate assessments of these diseases are lacking, particularly in tropical developing countries. We performed a series of studies in infants and primary school children in Fiji, a tropical developing country in the South Pacific. Impetigo was very common: more than a quarter of school-aged children and 12% of infants had active impetigo. Scabies was also very common affecting 18% of school children and 14% of infants. The group A streptococcus was the most common infective organism followed by Staphylococcus aureus. The size of the problem has been underestimated, particularly in the Pacific. It is time for more concerted public health efforts in controlling impetigo and scabies.

Acute post-streptococcal glomerulonephritis associated with prolonged hypocomplementaemia

The case of a 6-year-old boy who presented with acute post-streptococcal glomerulonephritis is reported. C3 levels and complement alternative pathway activity remained low for at least 10 months after presentation, before returning to normal. There was no evidence of other renal disease. This case highlights that hypocomplementaemia in acute post-streptococcal glomerulonephritis may persist for several months, and that prolonged hypocomplementaemia does not exclude this diagnosis.

Acute poststreptococcal glomerulonephritis: an update

PURPOSE OF REVIEW

Acute poststreptococcal glomerulonephritis, the most common form of acute glomerulonephritis in children, continues to be a major concern worldwide. This review summarizes the recent advances in the pathogenesis, host susceptibility factors, diverse clinical presentations, and treatment of the condition.

RECENT FINDINGS

Several recent advances have been made in identifying streptococcal antigens that may play a pathogenic role in acute poststreptococcal glomerulonephritis. Nephritis-associated streptococcal plasmin receptor and streptococcal pyrogenic exotoxin B are currently considered major putative nephritogens. Host susceptibility factors including HLA-DRB1*03011 have been found at a higher frequency in acute poststreptococcal glomerulonephritis patients than in healthy controls. Reversible posterior leukoencephalopathy and autoimmune hemolytic anemia are newly reported clinical associations with the disease. Studies from developing countries question whether the outcome is always benign. Treatment remains mostly conservative; however, controversy exists over the use of aggressive therapy with poor prognostic factors.

SUMMARY

Severe group A streptococcal disease including acute poststreptococcal glomerulonephritis remains a cause of morbidity and mortality in developing countries and among impoverished populations. Various reports on the diverse clinical manifestations that can be associated with the condition will aid physicians in prompt diagnosis and intervention, while studies focusing on better understanding of immunopathogenesis may facilitate vaccine development and prevention.