Acute Post-Streptococcal Glomerulonephritis in the Northern Territory of Australia: A Review of Data from 2009 to 2016 and Comparison with the Literature

The epidemiology of superficial Streptococcal A (impetigo and pharyngitis) infections in Australia: A systematic review

BACKGROUND

Streptoccocal A (Strep A, GAS) infections in Australia are responsible for significant morbidity and mortality through both invasive (iGAS) and post-streptococcal (postGAS) diseases as well as preceding superficial (sGAS) skin and throat infection. The burden of iGAS and postGAS are addressed in some jurisdictions by mandatory notification systems; in contrast, the burden of preceding sGAS has no reporting structure, and is less well defined. This review provides valuable, contemporaneous evidence on the epidemiology of sGAS presentations in Australia, informing preventative health projects such as a Streptococcal A vaccine and standardisation of primary care notification.

METHODS AND FINDINGS

MEDLINE, Scopus, EMBASE, Web of Science, Global Health, Cochrane, CINAHL databases and the grey literature were searched for studies from an Australian setting relating to the epidemiology of sGAS infections between 1970 and 2020 inclusive. Extracted data were pooled for relevant population and subgroup analysis. From 5157 titles in the databases combined with 186 grey literature reports and following removal of duplicates, 4889 articles underwent preliminary title screening. The abstract of 519 articles were reviewed with 162 articles identified for full text review, and 38 articles identified for inclusion. The majority of data was collected for impetigo in Aboriginal and Torres Strait Islander populations, remote communities, and in the Northern Territory, Australia. A paucity of data was noted for Aboriginal and Torres Strait Islander people living in urban centres or with pharyngitis. Prevalence estimates have not significantly changed over time. Community estimates of impetigo point prevalence ranged from 5.5-66.1%, with a pooled prevalence of 27.9% [95% CI: 20.0-36.5%]. All studies excepting one included >80% Aboriginal and Torres Strait Islander people and all excepting two were in remote or very remote settings. Observed prevalence of impetigo as diagnosed in healthcare encounters was lower, with a pooled estimate of 10.6% [95% CI: 3.1-21.8%], and a range of 0.1-50.0%. Community prevalence estimates for pharyngitis ranged from 0.2-39.4%, with a pooled estimate of 12.5% [95% CI: 3.5-25.9%], higher than the prevalence of pharyngitis in healthcare encounters; ranging from 1.0-5.0%, and a pooled estimate of 2.0% [95% CI: 1.3-2.8%]. The review was limited by heterogeneity in study design and lack of comparator studies for some populations.

CONCLUSIONS

Superficial Streptococcal A infections contribute to an inequitable burden of disease in Australia and persists despite public health interventions. The burden in community studies is generally higher than in health-services settings, suggesting under-recognition, possible normalisation and missed opportunities for treatment to prevent postGAS. The available, reported epidemiology is heterogeneous. Standardised nation-wide notification for sGAS disease surveillance must be considered in combination with the development of a Communicable Diseases Network of Australia (CDNA) Series of National Guideline (SoNG), to accurately define and address disease burden across populations in Australia.

TRIAL REGISTRATION

This review is registered with PROSPERO. Registration number: CRD42019140440.

Infection-Related Glomerulonephritis in Children and Adults

Infection-related glomerulonephritis is an immunologically mediated glomerular injury after an infection. Glomerulonephritis may occur with the infection or after a variable latent period. Poststreptococcal glomerulonephritis (PSGN) is the prototype of infection-related glomerulonephritis. The streptococcal antigens, nephritis-associated plasmin-like receptor and streptococcal exotoxin B, have emerged as major players in the pathogenesis of PSGN. Although PSGN is the most common infection-related glomerulonephritis in children, in adults, glomerulonephritis is secondary to bacteria such as staphylococci, viruses such as hepatitis C, and human immunodeficiency virus, and, rarely, parasitic infections. Supportive therapy is the mainstay of treatment in most infection-related glomerulonephritis. Treatment of the underlying infection with specific antibiotics and antiviral medications is indicated in some infections. Parasitic infections, although rare, may be associated with significant morbidity. Poststreptococcal glomerulonephritis is a self-limiting condition with a good prognosis. However, bacterial, viral, and parasitic infections may be associated with significant morbidity and long-term consequences. Epidemiologic studies are required to assess the global burden of infection-related glomerulonephritis. A better understanding of the pathogenesis of infection-related glomerulonephritis may unravel more treatment options and preventive strategies.

Disease profiles in the Indigenous Australian population are suggestive of a common complement control haplotype

Aboriginal and Torres Strait Islander People (respectfully referred to as Indigenous Australians herein) are disparately burdened by many infectious and chronic diseases relative to Australians with European genetic ancestry. Some of these diseases are described in other populations to be influenced by the inherited profile of complement genes. These include complement factor B, H, I and complement factor H-related (CFHR) genes that can contribute to a polygenic complotype. Here the focus is on the combined deletion of CFHR1 and 3 to form a common haplotype (CFHR3-1Δ). The prevalence of CFHR3-1Δ is high in people with Nigerian and African American genetic ancestry and correlates to a higher frequency and severity of systemic lupus erythematosus (SLE) but a lower prevalence of age-related macular degeneration (AMD) and IgA-nephropathy (IgAN). This pattern of disease is similarly observed among Indigenous Australian communities. Additionally, the CFHR3-1Δ complotype is also associated with increased susceptibility to infection with pathogens, such as Neisseria meningitidis and Streptococcus pyogenes, which also have high incidences in Indigenous Australian communities. The prevalence of these diseases, while likely influenced by social, political, environmental and biological factors, including variants in other components of the complement system, may also be suggestive of the CFHR3-1Δ haplotype in Indigenous Australians. These data highlight a need to define the Indigenous Australian complotypes, which may lead to the discovery of new risk factors for common diseases and progress towards precision medicines for treating complement-associated diseases in Indigenous and non-Indigenous populations. Herein, the disease profiles suggestive of a common complement CFHR3-1Δ control haplotype are examined.

Kidney Health of Indigenous Children: Insights from Australia, Aotearoa New Zealand, and Canada

Purpose of Review

This review seeks to highlight the common and unique factors that impact the kidney health of Indigenous children in Australia, Aotearoa New Zealand, and Canada with a particular interest on efforts to improve their kidney health outcomes and the framework to pursue future efforts.

Recent Findings

In the period since the adoption of the United Nations (UN) Declaration on the Rights of Indigenous People (UNDRIP) there has been a number of studies documenting poorer renal health outcomes and potential causes amongst Indigenous paediatric populations in Australia, Aotearoa New Zealand, and Canada. There is a shortage of studies that look at interventions to improve these outcomes.

Summary

Poorer kidney health outcomes amongst Indigenous children are rarely genetic and appear to be more related to societal inequities. Reported efforts to improve outcomes are few but have demonstrated the ability to make change and with sustained focus on reducing inequities there is hope to improve the renal health of Indigenous children.

Twenty-year Follow-up of Patients With Epidemic Glomerulonephritis due to Streptococcus zooepidemicus in Brazil

Introduction

Post-streptococcal glomerulonephritis (PSGN) has a good prognosis in children, but few studies have evaluated the long-term renal outcomes in adults with PSGN.

Methods

In a follow-up study, 47 predominantly adult patients with PSGN due to group C Streptococcus zooepidemicus were reassessed 20 years after an outbreak in Nova Serrana, Brazil. We evaluated clinical characteristics, renal outcomes, and the trajectory of the estimated glomerular filtration rate (eGFR) by the creatinine-based chronic kidney disease-epidemiology collaboration equation from 5 follow-up assessments. Logistic regression and mixed-effects regression were used in the analysis.

Results

After 20 years, the participants’ mean age was 56.6±15.1 years. Thirty-four (72%) patients had hypertension, 21 (44.7%) had eGFR <60 ml/min per 1.73 m², 8 of 43 (18.6%) had urine protein-to-creatinine ratio >150 mg/g, and 25 (53%) had CKD (low eGFR and/or increased proteinuria). Increasing age was associated with CKD (odds ratio: 1.07; 95% confidence interval [CI]: 1.02–1.13; P = 0.011) in multivariate analysis. The mean eGFR decline in the last 11 years of follow-up was −3.2 ml/min per 1.73 m² per year (95% CI: −3.7 to −2.7). Older age at baseline (coefficient −1.05 ml/min per 1.73 m² per year; 95% CI −1.28 to −0.81; P < 0.001), and hypertension 5 years after the outbreak (coefficient −7.78 ml/min/1.73 m²; 95% CI −14.67 to −0.78; P = 0.027) were associated with lower eGFR during the whole study period.

Conclusion

There was a marked worsening of renal function and a high prevalence of CKD and hypertension after 20 years of PSGN outbreak. Long-term follow-up is warranted after PSGN, especially among older patients.

Incidence of poststreptococcal glomerulonephritis in northwestern Ontario: Cross-sectional study at a tertiary care centre

OBJECTIVE

To measure the incidence of poststreptococcal glomerulonephritis (PSGN) and resulting complications in northwestern Ontario, including among Indigenous and rural populations.

DESIGN

Cross-sectional study.

SETTING

As the only tertiary care hospital in northwestern Ontario, Thunder Bay Regional Health Sciences Centre (TBRHSC) functions as the primary referral centre for most of the region. The catchment population has substantial Indigenous (21.5%) and rural (34.2%) populations.

PARTICIPANTS

All cases of PSGN managed at TBRHSC over an 8-year period from January 1, 2010, to December 31, 2017.

MAIN OUTCOME MEASURES

Cases were classified as confirmed, probable, or possible based on the type of evidence available. Patients' rurality and Indigenous status were recorded. Incidence rates and incidence rate ratios of all, pediatric (<18 years), and adult PSGN cases were calculated, as were incidence rates and incidence rate ratios of those requiring dialysis. Linear interpolation and extrapolation were used to estimate the population in non-census years.

RESULTS

Over the 8-year study period, 33 cases of PSGN were observed with annual incidence rates of 0.0 to 4.8 per 100,000 person-years and a mean annual incidence rate of 1.8 (95% CI 1.2 to 2.5) per 100,000 person-years. Of these 33 cases, 28 were confirmed with renal biopsy or clinical and laboratory data. Indigenous patients accounted for 61% (n=17) of confirmed cases and were 6.0 (95% CI 2.8 to 13, P<.001) times as likely to have PSGN and 9.6 (95% CI 3.0 to 31, P<.001) times as likely to require dialysis compared with non-Indigenous patients. Patients living in rural areas accounted for 71% (n=20) of confirmed cases and were 3.2 (95% CI 1.4 to 7.3, P=.006) times as likely to have PSGN and 3.9 (95% CI 1.0 to 10, P=.02) times as likely to require dialysis compared with patients in urban areas.

CONCLUSION

The main burden of PSGN in northwestern Ontario occurs among Indigenous and rural populations. Additional research is required to investigate the true overall burden of PSGN in the region. In collaboration with regional Indigenous groups, advocacy is needed for PSGN to be made reportable and public health action must be taken to address these pronounced disparities.

Protocol for the systematic review of the epidemiology of superficial Streptococcal A infections (skin and throat) in Australia

OBJECTIVE

We have produced a protocol for the comprehensive systematic review of the current literature around superficial group A Streptococcal infections in Australia.

METHODS

MEDLINE, Scopus, EMBASE, Web of Science, Global Health, Cochrane, CINAHL databases and the gray literature will be methodically and thoroughly searched for studies relating to the epidemiology of superficial group A Streptococcal infections between the years 1970 and 2019. Data will be extracted to present in the follow up systematic review.

CONCLUSION

A rigorous and well-organised search of the current literature will be performed to determine the current and evolving epidemiology of superficial group A Streptococcal infections in Australia.

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.

Burn Injuries in Hospitalized Australian Children-An Epidemiological Profile

Globally, First Nations children sustain burns at a higher rate than other children. Little is understood about how health inequities contribute, especially from an Indigenous viewpoint. We analyzed data from the Burns Registry of Australian and New Zealand (BRANZ) for acute burns in children (<16 years) admitted to hospital between October 2009 and July 2018. Descriptive statistics examined equity variables in patient and injury characteristics. Poisson regression was used to describe factors associated with bacterial infection. Indigenous research methods were used throughout. Aboriginal and Torres Strait Islander children represented 10.4% of the study population. Health inequities were present for Aboriginal and Torres Strait Islander children with longer hospital length of stay (9.5 vs 4.6 days), rural residency (61.3% vs 13.9%), lower socioeconomic status (72.2% vs 34.9%), and more flame burns (19.5% vs 10.6%) compared to other Australian children. Streptococcus sp. infection risk was four times greater in Aboriginal and Torres Strait Islander children compared to other Australian children. Flame burns and high percentage total body surface area burns were a risk for Staphylococcus sp. and Streptococcus sp. infection in all children. The epidemiological profile for burn injuries managed in Australian burns centers differs between Aboriginal and Torres Strait Islander children and other children, indicating persistent health inequities. These differences should be considered in the development of injury prevention strategies and the clinical management of burn injuries for Aboriginal and Torres Strait Islander children and their families.

Characteristics and Impact of Disseminated Gonococcal Infection in the "Top End" of Australia

The "Top End" of Australia is presently experiencing a gonorrhea epidemic. Gonococcal infection is usually limited to mucosal tissues but can lead to disseminated gonococcal infection (DGI), joint destruction, and severe sepsis. This study aimed to explore the epidemiology, presentation, management, and health-care impact of DGI in the Top End of the Northern Territory. Health records of patients diagnosed with proven, probable, or possible DGI between January 2010 and September 2018 were analyzed retrospectively. One hundred six cases of DGI were identified. Ninety-four patients (88.7%) were Indigenous Australian. The incidence of proven and probable DGI in the Indigenous population was 27.1 per 100,000 person-years, compared with 7.1 in the Top End population overall. Of 7,540 laboratory-proven gonococcal notifications, 1.3% (n = 97) were complicated by DGI. The highest incidence was in the 15-19-year age-group. Thirteen cases (12.3%) occurred in patients younger than 15 years. High rates of comorbid alcohol misuse, diabetes, systemic lupus erythematosus, rheumatic fever, and complement deficiency were observed. The "classic triad" of tenosynovitis, dermatitis, and polyarthralgia was rare. Ninety-four patients (88.7%) presented with purulent arthritis. Disseminated gonococcal infection was estimated to cause at least 10.0% of nonpenetrating septic arthritis in the Top End and 1,234 days of hospitalization during the study period. DGI is an important cause of morbidity in the Top End, particularly in the young, remote Indigenous Australian population. Clinical presentation varies from classical teaching. Urgent action in the health and community sector is required, particularly for at-risk populations, to prevent further debilitating and costly complications of gonococcal infection.

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.