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

Low prevalence of scabies and impetigo in Dakar/Senegal: A cluster-randomised, cross-sectional survey

BACKGROUND

Scabies, a parasitic infection caused by Sarcoptes scabiei var. hominis, is a public health problem with significant morbidity worldwide, particularly in low-resource countries. Impetigo, a complication of scabies infection, is a risk factor for sepsis, glomerulonephritis and possibly acute rheumatic fever. Currently, the majority of epidemiological data has been collected in rural populations in the Pacific with limited applicability to urban populations in sub-Saharan Africa, where scabies is also believed to be a problem. To inform future public health programs, more reliable information about the burden of disease is required.

METHODOLOGY/PRINCIPAL FINDINGS

In July/August 2022, we conducted a cross sectional, cluster-randomised, household survey in Pikine/Dakar using the 'International Association for the Control of Scabies (IACS)' criteria to diagnose scabies and impetigo. All participants underwent a standardised clinical examination by post-graduate dermatology students. For those diagnosed with scabies, an age-adapted 'Dermatology Life Quality Index (DLQI)' questionnaire was filled. We recruited and examined 1697 participants to detect 27 cases of scabies (prevalence: 1.6%, 95% CI 0.8-3.2), mostly in school aged children. Ten participants suffered from impetigo (prevalence: 0.6%, 95% CI 0.3-1.3), 5 of which were dually infected with scabies. Risk factors for scabies infection were young age, male gender and Koranic school attendance. Of those found to have scabies, in 7 out of 22 cases (31.8%) it had a large effect on their lives according to the DLQI questionnaires filled.

CONCLUSIONS/SIGNIFICANCE

This study adds to the mapping of the burden of scabies across Africa to support public health action. With a low prevalence of scabies that is concentrated amongst poor households and children attending Koranic schools, a focused public health approach targeting Koranic schools and poor households seems to be most appropriate in this community.

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.

Burden of Paediatric Kidney Diseases in a Tertiary Care Hospital in Harare, Zimbabwe

Background

The pattern of paediatric kidney diseases across different regions is influenced by genetic, racial, and environmental differences.

Objectives

The aim of this study was to review the current spectrum and outcome of childhood kidney diseases at Parirenyatwa Group of Hospitals and highlight the challenges of care.

Design

Retrospective observational study.

Methods

Data on all children below 16 years of age hospitalised for any kidney disease over an 8-month period (1 January-31 August 2022) were retrieved and retrospectively analysed. Kidney diseases were categorised as per standard definitions.

Results

Kidney disease accounted for 2.2% (n = 50) of all 2264 admissions in the paediatric unit, with males constituting 60% (n = 30). Age ranged from 2 weeks to 13 years (mean 5.5 ± 3.5 years) with 58.0% being under 5 years. The commonest diagnoses in the unit were acute kidney injury (AKI) (n = 16, 32%) nephrotic syndrome (n = 16, 32%), hypertension (n = 12, 24%) and end stage kidney disease (ESKD) (n = 11, 22%) with some children presenting with more than 1 diagnosis. Only 3 out of 11 children with ESKD and 3 out of 8 children with AKI who required dialysis could be offered dialysis due to limited resources. Overall mortality rate was 32% (16/50): 5 children with AKI, 2 with nephrotic syndrome and normal kidney function, 8 with ESKD and 1 with Fanconi syndrome.

Conclusion

Childhood kidney disease contributes significantly to hospitalisations at our institution with highest mortality among children with ESKD. The study highlighted the need for provision of essential drugs and kidney replacement therapy for children with kidney disease at our institution.

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.

C10Pred: A First Machine Learning Based Tool to Predict C10 Family Cysteine Peptidases Using Sequence-Derived Features

Streptococcus pyogenes, or group A Streptococcus (GAS), a gram-positive bacterium, is implicated in a wide range of clinical manifestations and life-threatening diseases. One of the key virulence factors of GAS is streptopain, a C10 family cysteine peptidase. Since its discovery, various homologs of streptopain have been reported from other bacterial species. With the increased affordability of sequencing, a significant increase in the number of potential C10 family-like sequences in the public databases is anticipated, posing a challenge in classifying such sequences. Sequence-similarity-based tools are the methods of choice to identify such streptopain-like sequences. However, these methods depend on some level of sequence similarity between the existing C10 family and the target sequences. Therefore, in this work, we propose a novel predictor, C10Pred, for the prediction of C10 peptidases using sequence-derived optimal features. C10Pred is a support vector machine (SVM) based model which is efficient in predicting C10 enzymes with an overall accuracy of 92.7% and Matthews’ correlation coefficient (MCC) value of 0.855 when tested on an independent dataset. We anticipate that C10Pred will serve as a handy tool to classify novel streptopain-like proteins belonging to the C10 family and offer essential information.

Using Genomics to Understand the Epidemiology of Infectious Diseases in the Northern Territory of Australia

The Northern Territory (NT) is a geographically remote region of northern and central Australia. Approximately a third of the population are First Nations Australians, many of whom live in remote regions. Due to the physical environment and climate, and scale of social inequity, the rates of many infectious diseases are the highest nationally. Molecular typing and genomic sequencing in research and public health have provided considerable new knowledge on the epidemiology of infectious diseases in the NT. We review the applications of genomic sequencing technology for molecular typing, identification of transmission clusters, phylogenomics, antimicrobial resistance prediction, and pathogen detection. We provide examples where these methodologies have been applied to infectious diseases in the NT and discuss the next steps in public health implementation of this technology.

Sociodemographic determinants of chronic kidney disease in Indigenous children

Rates of chronic kidney disease (CKD) are disproportionately increased in Indigenous peoples. The focus has traditionally been on adults, as they experience the highest rates of kidney failure requiring kidney replacement therapy. The impacts of colonization, systemic racism, and sociodemographic marginalization however impact the health of Indigenous peoples across the lifespan. This review presents the social context within which Indigenous children develop and the impact relevant to kidney health across the developmental stages. In utero exposures impact nephron endowment which can manifest in glomerular hyperfiltration and sclerosis as well as an increased risk of congenital anomalies of the kidney and urinary tract. Young children are at increased risk of autoimmune conditions, secondary to infectious and environmental exposures, and are also exposed to the impacts of a Western lifestyle manifesting early onset overweight/obesity. Adolescents begin to manifest more severe metabolic complications such as type 2 diabetes. The impacts of early onset diabetes are associated with aggressive kidney complications and high rates of kidney failure in young adulthood. Finally, the key elements of successful prevention and treatment strategies are discussed including the importance of screening for asymptomatic, modifiable early disease, linked with clinical primary and tertiary care follow-up, and culturally relevant and safe care.

Association of Built Environmental Features with Rates of Infectious Diseases in Remote Indigenous Communities in the Northern Territory, Australia

The health of Indigenous Australians is far poorer than non-Indigenous Australians, including an excess burden of infectious diseases. The health effect of built environmental (BE) features on Indigenous communities receives little attention. This study’s objective was to determine associations between BE features and infectious disease incidence rates in remote Indigenous communities in the Northern Territory (NT), Australia. Remote Indigenous communities (n = 110) were spatially joined to 93 Indigenous Locations (ILOC). Outcomes data were extracted (NT Notifiable Diseases System) and expressed as ILOC-specific incidence rates. Counts of buildings were extracted from community asset maps and grouped by function. Age-adjusted infectious disease rates were dichotomised, and bivariate binomial regression used to determine the relationships between BE variables and infectious disease. Infrastructure Shelter BE features were universally associated with significantly elevated disease outcomes (relative risk 1.67 to 2.03). Significant associations were observed for Services, Arena, Community, Childcare, Oval, and Sports and recreation BE features. BE groupings associated with disease outcomes were those with communal and/or social design intent or use. Comparable BE groupings without this intent or use did not associate with disease outcomes. While discouraging use of communal BE features during infectious disease outbreaks is a conceptually valid countermeasure, communal activities have additional health benefits themselves, and infectious disease transmission could instead be reduced through repairs to infrastructure, and more infrastructure. This is the first study to examine these associations simultaneously in more than a handful of remote Indigenous communities to illustrate community-level rather than aggregated population-level associations.

Healthy Skin, Healthy Mepla: A skin health promotional event for children in the Torres Strait

ISSUE ADDRESSED

Skin infections such as impetigo and scabies are common in Aboriginal Australian and Torres Strait Islander children living in rural and remote settings. Effective health promotion is a key element when addressing health literacy aimed at reducing the burden of skin disease. Community-driven health promotion provides a potentially effective and sustainable model for improved health outcomes.

METHODS

A one-day community-driven skin health promotional event was conducted on Waiben [Thursday Island] with the aim of improving local Torres Strait Islander children's appreciation of the importance of skin health through art, music and creation of a video. Participants completed written pre- and post-questionnaires to determine their response.

RESULTS

Fifty-two children participated in the event; median (range) age was 11 (9-12) years and all identified as Torres Strait Islander. Overall, 34 of 50 children (68%) felt that participating in this workshop improved their skin health knowledge.

CONCLUSIONS

Skin health promotion can be successful achieved through a locally conceived, locally driven and locally owned approach. SO WHAT?: This skin health promotional event could be a model for other health promotion activities in the Torres Strait.

The development of a community-based public health response to an outbreak of post-streptococcal glomerulonephritis in a First Nations community

Background

Post-streptococcal glomerulonephritis (PSGN) is a rare immune-mediated condition that typically occurs in children as a result of group A streptococcus (GAS) infection. PSGN is not considered a disease of public health significance, or reportable, in Canada. Higher incidence of PSGN has been described among Indigenous people in Canada. No national or provincial guidance exists to define or manage PSGN outbreaks.

Objective

To describe an outbreak of seven paediatric cases of PSGN in a remote First Nations community in northwestern Ontario and the development of a community-wide public health response.

Methods

Following a literature review, an intervention was developed involving screening of all children in the community for facial or peripheral edema or skin sores, and treatment with antibiotics if noted. Case, contact and outbreak definitions were also developed. The purpose of the response was to break the chain of transmission of a possible nephritogenic strain of streptococcus circulating in the community. Relevant demographic, clinical and laboratory data were collected on all cases.

Outcome

Seven paediatric cases of PSGN presented to the community nursing station between September 25 and November 29, 2017. Community-wide screening for skin sores was completed for 95% of the community's children, including 17 household contacts, and as a result, the last of the cases was identified. Nineteen adult household contacts were also screened. Ten paediatric contacts and two adult contacts with skin sores were treated with one dose of intramuscular penicillin, and six paediatric contacts received oral cephalexin. No further cases were identified following the screening.

Conclusion

PSGN continues to occur in Indigenous populations worldwide at rates higher than in the overall population. In the absence of mandatory reporting in Canada, the burden of PSGN remains underappreciated and could undermine upstream and downstream public health interventions. Evidence-based public health guidance is required to manage outbreaks in the Canadian context. The community-based response protocol developed to contain the PSGN outbreak in this First Nations community can serve as a model for the management of future PSGN outbreaks.

Increasing Incidence of Invasive Group A Streptococcus Disease in First Nations Population, Alberta, Canada, 2003-2017

The incidence of invasive group A Streptococcus (iGAS) disease in the general population in Alberta, Canada, has been steadily increasing. To determine whether rates for specific populations such as First Nations are also increasing, we investigated iGAS cases among First Nations persons in Alberta during 2003-2017. We identified cases by isolating GAS from a sterile site and performing emm typing. We collected demographic, social, behavioral, and clinical data for patients. During the study period, 669 cases of iGAS in First Nations persons were reported. Incidence increased from 10.0 cases/100,000 persons in 2003 to 52.2 cases/100,000 persons in 2017. The 2017 rate was 6 times higher for the First Nations population than for non-First Nations populations (8.7 cases/100,000 persons). The 5 most common emm types from First Nations patients were 59, 101, 82, 41, and 11. These data indicate that iGAS is severely affecting the First Nations population in Alberta, Canada.

Housing conditions and health in Indigenous Australian communities: current status and recent trends

Ensuring sufficient and adequately maintained housing in Indigenous Australian communities remains an ongoing policy challenge for government, with major implications for the health of Indigenous Australians. This study sought to characterise the current status of housing conditions experienced by Indigenous Australians, with special reference to the Northern Territory. The assessment examined a range of indicators relating to crowding, dwelling condition, 'health hardware', and provision of maintenance and repairs. While acknowledging data deficiencies and inconsistencies, the analysis produced mixed results. There was evidence of a reduction in crowding but little observable improvement in the provision of maintenance and repairs. Some housing-related health outcomes have shown improvement, though these have tended to coincide with mass treatment campaigns. Achieving the goal of healthy homes - and ultimately closing the gap on Indigenous disadvantage - requires further investment in new houses that are appropriately designed and constructed, alongside an increased emphasis on cyclical maintenance.

Scabies and impetigo in Samoa: A school-based clinical and molecular epidemiological study

Background

Common infections of the skin such as impetigo and scabies represent a large burden of disease globally, being particularly prevalent in tropical and resource-limited settings. Efforts to address these infections through mass drug administrations have recently been shown as efficacious and safe. In Samoa, a Pacific Island nation, there is a marked lack of epidemiological data for these neglected tropical diseases, or appreciation of their drivers in this setting.

Methods

An observational, cross-sectional survey of children aged between 4 and 15 years attending primary schools in rural areas of Upolu Island, Samoa was carried out to assess the prevalence of impetigo and scabies in schoolchildren residing in rural Samoa, integrated with descriptive epidemiological and microbial genomic data. A phylogenetic assessment of local Staphylococcus aureus isolated from Samoan schoolchildren was performed to estimate putative community transmission.

Findings

In this survey, the prevalence of impetigo observed in Samoan schoolchildren was one of the highest described globally (57•1%, 95% CI [53•8-60•5%], 476/833). Associations between active impetigo and age and gender were noted, with younger children and males more commonly affected (aOR2•8 [1•8-4•7]and aOR1•8 [1•3-2•5], respectively). The prevalence of scabies was similar to that seen in other South Pacific island countries (14•4%, 95% CI [12•2-17•0%], 120/833). Transmission of S. aureus was predicted, primarily between those children attending the same school. Carriage of S. pyogenes was notably low, with pharyngeal carriage observed in less than 2% of schoolchildren, consistent with earlier studies from Samoa.

Interpretation

This study describes a considerable burden of disease attributed to impetigo and scabies in Samoa. These findings will be valuable in addressing the public health challenge posed by these conditions, providing baseline prevalence data and highlighting practical strategies to reduce transmission of relevant microbes and parasites in this setting.

Tala Tomua

O a'afiaga o le pa'u i fa'ama'i o le po'u (impetigo) ma le utu o le pa'u (scabies), ua tele naua le fanau ua maua ai i le pasefika, ma le lalolagi atoa. O fuafuaga vaai mamao ma polokalame e fofoina ai nei faafitauli, e aofia ai le inumaga o fualaau e tapeina ai nei fa'ama'i, ua aliali mai ai e mafai ona faatamaia nei fa'ama'i. E le o tele ni tusitusiga ma faamaumauga i totonu o Samoa, pe ta'atele nei fa'amai o le pa'u pe leai. Ona o le le faatauaina o nei fa'ama'i, e le o iloa fo'i ni mafuaga ma nisi tulaga e faateleina ai nei fa'ama'i o le pa'u i Samoa.

Faatinoina o le suesuega

O le suesuega faasaenisi i le fanau aoga i le va o le 4 ma le 15 tausaga o loo ao'oga i le tulaga lua i nisi o nu'u i tua i Upolu, na faatinoina ai suesuega lea, ia suesueina ai le aotelega ma fainumera o le fanau ua maua i fa'ama'I o le po'u (impetigo) ma le utu o le pa'u (scabies). O lenei foi suesuega, na fia iloa ai fo'i po'o a ituaiga siama eseese o loo maua i luga o pa'u ma tino o le fanau aoga, ina ia iloa ai foi auala ua pipisi ai nei siama mai le isi tamaitiiti i le isi, ona mafua ai lea o nei fa'ama'i o le pa'u.

Tanuuga o le suesuega

Ua faailoa mai i le suesuega, le ta'atele o le fa'ama'i o le po'u (impetigo) ua maua ai le fanau aoga (57%), i aoga na faia ai le suesuega. O se fainumera ua maualuga tele i le lalolagi atoa. E toatele atu nisi o le fanau laiti (younger) ma tama (male) e maua i le po'u nai lo isi tamaiti. O le fainumera o le utu o le pa'u (scabies) (14·4%) e tai tutusa lava ma isi motu o le Pasefika. O le feaveaina o le siama faapitoa (staph aureus) ua tupu lea i le fanau ua ao'oga i le aoga e tasi. E le toatele foi nisi o le fanau (2%) na maua i le siama faapitoa o le fa'ai (strep pyogenes) e ona mafua ai le fiva rumatika. O lenei fainumera ua tai tutusa ma suesuega faasaenisi na fai muamua i Samoa.

Aotelega

O le aotelega la o lenei suesuega faasaenisi, ua faailoaina mai ai le tele naua o le fa'ama'i o le pa'u, o po'u (impetigo) ma le utu o le pa'u (scabies) i Samoa nei. O nei foi suesuega o le a aoga tele ini polokalame ma ni fuafuaga mamao e fa'afoisia ai nei faafitauli i le soifua maloloina o le fanau i Samoa. O le a avea foi nei fainumera e faamaumauina mo le silafia e le atunuu ma le soifua maloloina, le ta'atele o nei fa'amai o le pa'u, mo le tapenaina o ni fofo talafeagai ise taimi o i luma, ina ia faaitiitina ai le pipisi o nei siami i fanau ao'oga i Samoa.

Rheumatic heart disease: A review of the current status of global research activity

Rheumatic heart disease (RHD) is a serious and long-term consequence of acute rheumatic fever (ARF), an autoimmune sequela of a mucosal infection by Streptococcus pyogenes (Group A Streptococcus, Strep A). The pathogenesis of ARF and RHD is complex and not fully understood but involves host and bacterial factors, molecular mimicry, and aberrant host innate and adaptive immune responses that result in loss of self-tolerance and subsequent cross-reactivity with host tissues. RHD is entirely preventable yet claims an estimated 320 000 lives annually. The major burden of disease is carried by developing nations and Indigenous populations within developed nations, including Australia. This review will focus on the epidemiology, pathogenesis and treatment of ARF and RHD in Australia, where: streptococcal pyoderma, rather than streptococcal pharyngitis, and Group C and Group G Streptococcus, have been implicated as antecedents to ARF; the rates of RHD in remote Indigenous communities are persistently among the highest in the world; government register-based programs coordinate disease screening and delivery of prophylaxis with variable success; and researchers are making significant progress in the development of a broad-spectrum vaccine against Strep A.

The economic and health burdens of diseases caused by group A Streptococcus in New Zealand

OBJECTIVES

In preparation for the future arrival of a group A Streptococcus (GAS) vaccine, this study estimated the economic and health burdens of GAS diseases in New Zealand (NZ).

METHODS

The annual incidence of GAS diseases was based on extrapolation of the average number of primary healthcare episodes managed each year in general practices (2014-2016) and on the average number of hospitalizations occurring each year (2005-2014). Disease incidence was multiplied by the average cost of diagnosing and managing an episode of disease at each level of care to estimate the annual economic burden.

RESULTS

GAS affected 1.5% of the population each year, resulting in an economic burden of 29.2 million NZ dollars (2015 prices) and inflicting a health burden of 2373 disability-adjusted life years (DALYs). Children <5 years of age were the most likely age group to present for GAS-related healthcare. Presentations for superficial throat and skin infections (predominantly pharyngitis and impetigo) were more common than other GAS diseases. Cellulitis contributed the most to the total economic and health burdens. Invasive and immune-mediated diseases disproportionately contributed to the total economic and health burdens relative to their frequency of occurrence.

CONCLUSION

Preventing GAS diseases would have substantial economic and health benefits in NZ and globally.

A cross-sectional study of dermatological conditions in rural and urban Timor-Leste

BACKGROUND

There is limited information about the type of skin disease in Timor-Leste. In order to determine the type and magnitude of skin disease in Timor-Leste, we conducted a cross-sectional point prevalence study of 271 patients from rural and urban Timor-Leste. The aim of the study was to estimate the magnitude and burden of dermatological disease.

METHODS

Two Australian-trained dermatologists conducted clinics in the city of Dili (urban) and village of Manusae (rural) in Timor-Leste between the period of June and July 2016. They independently recorded all patient presentations and diagnoses.

RESULTS

A total of 271 patients were reviewed over two months, of whom 37% were seen in an urban setting and 63% in a rural setting. Scabies accounted for 96% of all presentations in the rural setting, which was significantly higher than its presentation in the urban setting (8%), P < 0.001. Scabies also accounted for the majority of presentations in the paediatric population aged 10 years or younger. Fungal and bacterial skin and soft tissue infections were both more common in urban areas (P < 0.001).

CONCLUSIONS

Scabies infection remains the most prevalent dermatological condition encountered in the Timor-Leste rural population and has hopefully been addressed by a recent mass drug administration. It is important to raise awareness of the systemic problems that can arise from untreated skin infections.

Clinicopathologic features of infection-related glomerulonephritis with IgA deposits: a French Nationwide study

Background

Infection-related glomerulonephritis with IgA deposits (IRGN-IgA) is a rare disease but it is increasingly reported in the literature. Data regarding epidemiology and outcome are lacking, especially in Europe. We aimed to assess the clinical, pathologic and outcome data of IRGN-IgA.

Methods

Clinical and outcome data from patients from 11 French centers over the 2007–2017 period were collected retrospectively. We reviewed pathologic patterns and immunofluorescence of renal biopsies and evaluated C4d expression in IRGN-IgA. We analyzed the correlation between histological presentation and outcome.

Results

Twenty-seven patients (23 men, mean age: 62 ± 15 years) were included. Twenty-one (78%) had Staphylococcus aureus infection and twelve (44%) were diabetic. At the time of biopsy, 95.2% had haematuria, 48.1% had a serum creatinine level of > 4 mg/dL, and 16% had hypocomplementemia. The most common pathologic presentation included mesangial (88.9%) and endocapillary proliferative glomerulonephritis (88.9%) with interstitial fibrosis and tubular atrophy (IF/TA) (85.1%). Diffuse and global glomerular C4d expression was found in 17.8%, mostly in biopsies with acute or subacute patterns, and was associated with a short delay between infection and renal biopsy compared to segmental and focal staining. After median follow-up of 13.2 months, 23.1% died, 46.2% had persistent renal dysfunction and 15.4% reached end-stage renal disease. Renal outcome was correlated to IF/TA severity.

Conclusions

Infection-related glomerulonephritis with IgA deposits is usually associated with Staphylococcus infections and mainly affects adult men. This entity has a poor prognosis which is correlated to interstitial fibrosis and tubular atrophy severity.

Incidence of Acute Post-Streptococcal Glomerulonephritis in Hawai'i and Factors Affecting Length of Hospitalization

Acute post-streptococcal glomerulonephritis (APSGN) is a disorder of inflammation in the glomeruli and vasculature of the kidneys that is caused by immune-complex formation after Streptococcus pyogenes infection. Most patients with APSGN present with macroscopic hematuria, edema, and hypertension, however presentation can vary from no symptoms to severe proteinuria, or even acute renal failure. This study sought to estimate the incidence of APSGN among children in Hawai'i, to identify populations at increased risk for APSGN, and to recognize risk factors correlated with the length of hospitalization by subtype of APSGN (eg, pyoderma-associated, pharyngitis-associated). This retrospective review of 106 patients found that the incidence of APSGN in Hawai'i is greater than 4 per 100,000 children, which is significantly higher than the incidence of APSGN in high-income countries at 0.3 per 100,000 children. This increased incidence may be due to Hawai'i's unique racial group composition and therefore the unique immunologic response of the children of Hawai'i (particularly Pacific Islanders, who represent 62% of patients with APSGN in this study, but only represent 10% of Hawai'i's general population). In addition, there may be increased prevalence of nephritogenic strains of Streptococcus pyogenes in Hawai'i. The length of hospitalization was significantly increased in children with elevated serum creatinine levels (P <.0001) and lower bicarbonate levels (P =.0003).

Case Report: Concurrent Rheumatic Fever and Acute Post-Streptococcal Glomerulonephritis in a High-Burden Setting

We report a case of acute rheumatic fever with severe pancarditis occurring simultaneously with probable acute post-streptococcal glomerulonephritis in a previously well, Australian Aboriginal, 29-year-old male. These autoimmune streptococcal sequelae are usually considered pathogenetically distinct, and concurrence has not previously been reported from this high-burden setting. We hypothesize that a single type of infecting group A Streptococcus (Strep A) triggered both autoimmune sequelae. Salient features included mitral and aortic regurgitation that worsened during the acute illness, painful pericarditis, and high troponin; severe acute kidney injury with oliguria, hematuria, and macroalbuminuria; reduced complement (C3); and elevated streptococcal serology. The case highlights important diagnostic and management challenges. It also illustrates the serious morbidity impact of the complications of Strep A.

Systematic Review of Group A Streptococcal emm Types Associated with Acute Post-Streptococcal Glomerulonephritis

Acute post-streptococcal glomerulonephritis (APSGN) is a postinfectious immune-mediated kidney disease associated with group A Streptococcus (GAS). The prevalence of APSGN varies within and between countries and is influenced by socioeconomic, host, and bacterial factors. The disease is more prevalent in developing countries and resource-poor settings of developed countries, such as the Indigenous populations residing in tropical Australia. The M-protein is a universally present GAS surface antigen that is the focus of molecular typing and vaccine research. Early reports suggested that some M-proteins (emm types) are more likely to cause APSGN than others. Here, we present the first systematic review of the global distribution of APSGN-associated GAS emm types. There were 46 emm types among the 676 cases described in 15 reviewed articles. Only 43% APSGN cases would have had theoretical coverage from the experimental M protein-based GAS vaccine. Vaccine coverage was higher in regions such as North America (97%) and the United Kingdom (98%) than Africa (67%) and Australia (38%). Variable vaccine coverage against APSGN- associated emm types highlights the need for further research into this disease, particularly in settings of poverty, where APSGN prevalence is higher. Three GAS emm types (emm49, emm60, and emm55) consistently occur in APSGN cases around the world. Future studies would therefore benefit from examining the genomic epidemiology of these emm types to unravel potential markers of APSGN.

Burden of skin disease in two remote primary healthcare centres in northern and central Australia

The burden of skin infections across all age groups in remote Australian Indigenous communities is currently unknown. In a retrospective audit of 439 residents from two remote communities presenting to health clinics, skin conditions were the most common reason for presentation (1603/7392, 22%) and 330/439 (75%) residents presented at least once with a skin infection. Skin infections are an under-appreciated and dominant reason for presentation to primary healthcare centres in these indigenous communities and public health campaigns to address this should incorporate all age groups.

SToP (See, Treat, Prevent) skin sores and scabies trial: study protocol for a cluster randomised, stepped-wedge trial for skin disease control in remote Western Australia

INTRODUCTION

Skin is important in Australian Aboriginal culture informing kinship and identity. In many remote Aboriginal communities, scabies and impetigo are very common. Untreated skin infections are painful, itchy and frequently go untreated due to under-recognition and lack of awareness of their potential serious complications. We hypothesise that the skin infection burden in remote Aboriginal communities can be reduced by implementing streamlined training and treatment pathways integrated with environmental health and health promotion activities, tested in the See, Treat, Prevent (SToP skin sores and scabies) trial.

METHODS AND ANALYSIS

SToP will evaluate a skin control programme using a stepped-wedge, cluster randomised trial design with three intervention components (the 'SToP activities'): (1) seeing skin infections (development of training resources implemented within a community dermatology model); (2) treating skin infections (employing the latest evidence for impetigo, and scabies treatment); and (3) preventing skin infections (embedded, culturally informed health promotion and environmental health activities). Four community clusters in the remote Kimberley region of Western Australia will participate. Following baseline data collection, two clusters will be randomly allocated to the SToP activities. At 12 months, the remaining two clusters will transition to the SToP activities. The primary outcome is the diagnosis of impetigo in children (5-9 years) at school-based surveillance. Secondary outcome measures include scabies diagnosis, other child health indicators, resistance to cotrimoxazole in circulating pathogenic bacteria, determining the economic burden of skin disease and evaluating the cost effectiveness of SToP activities.

ETHICS AND DISSEMINATION

This study protocol was approved by the health ethics review committees at the Child and Adolescent Health Service (Approval number RGS0000000584), the Western Australian Aboriginal Health Ethics Committee (Reference number: 819) and the University of Western Australia (Reference RA/4/20/4123). Study findings will be shared with community members, academic and medical communities via publications and presentations, and in reports to funders. Authorship for all publications based on this study will be determined in line with the Uniform Requirements for Manuscripts Submitted to Biomedical Journals published by the International Committee of Medical Journal Editors. Sharing results with organisations and communities who contributed to the study is paramount. The results of the SToP trial will be shared with participants in a suitable format, such as a single summary page provided to participants or presentations to communities, the Kimberly Aboriginal Health Planning Forum Research Subcommittee and other stakeholders as appropriate and as requested. Communication and dissemination will require ongoing consultation with Aboriginal communities to determine appropriate formats.

TRIAL REGISTRATION NUMBER

ACTRN12618000520235.

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

Acute post-streptococcal glomerulonephritis (APSGN) is an inflammatory kidney disease following infection with nephritogenic strains of Group A Streptococcus. In 1991, APSGN became notifiable in the Northern Territory (NT) of Australia with cases recorded on the NT Notifiable Disease Database (NTNDS). The case definition of a confirmed case requires laboratory definitive evidence or laboratory suggestive evidence in conjunction with a clinically compatible illness. Probable cases require clinical evidence only. Acute post-streptococcal glomerulonephritis notifications from 2009 to 2016 were extracted from the NTNDS. Of the 322 cases, 261 were confirmed and 61 probable. The majority, 304 (94%), were Aboriginal and the median age was 8 years (range: 0–62 years). Incidence for confirmed cases was 13.8/100,000 person-years, with inclusion of probable cases increasing incidence to 17.0/100,000 person-years. Highest incidence of confirmed cases was in Aboriginal children less than 15 years of age at 124.0 cases/100,000 person-years. The rate ratio of confirmed cases in Aboriginal to non-Aboriginal Australians was 18.9 (95% confidence interval: 11.4–33.6). Recent trends show a consistently high number of notifications annually with less frequent outbreaks. The Aboriginal population of the NT continues to have high rates of APSGN with recent trends showing higher rates than previously reported. Sustained preventative efforts and continued surveillance strategies are needed.

Concerns for efficacy of a 30-valent M-protein-based Streptococcus pyogenes vaccine in regions with high rates of rheumatic heart disease

The prevalence of rheumatic heart disease (RHD) in the Aboriginal population of the Australian Northern Territory is high, and Streptococcus pyogenes skin infections likely contribute to this. A promising candidate S. pyogenes “30mer” vaccine is composed of 30 pharyngitis associated type-specific antigens from the S. pyogenes M protein. Cross opsonisation experiments suggest that 30mer vaccine protection may extend to non-cognate emm types. A new “emm cluster” scheme for classifying M protein is based on the full-length coding sequence, and correlates with functional and immunological properties, and anatomical tropism. Twenty-seven years of research in the Northern Territory has yielded 1810 S. pyogenes isolates with clinical and emm type data. The primary aim was to analyse these data with reference to the emm cluster scheme and cross opsonisation information, to inform estimation of 30mer vaccine efficacy in the Northern Territory. The isolates encompass 101 emm types. Variants of cluster A-C were enriched in throat isolates, and variants of emm cluster D enriched in skin isolates. Throat isolates were enriched for 30mer vaccine cognate emm types in comparison with skin isolates of which only 25% were vaccine emm types. While cross opsonisation data indicates potential for enhancing 30mer vaccine coverage, more than one third of skin isolates were within 38 emm types untested for cross opsonisation. Emm cluster D variants, in particular emm cluster D4, were not only all non-cognate with the vaccine, but were abundant and diverse, and less likely to be cross-opsonisation positive than other emm clusters. Long term persistence of many emm types in the study area was revealed. It was concluded that the 30mer vaccine efficacy in the Northern Territory will likely require both cross protection, and additional measures to elicit immunity against variants of emm cluster D.

The bacterium Streptococcus pyogenes causes throat and skin infections. A danger from such infections is an immune response that attacks human heart tissue, leading to rheumatic heart disease, which is difficult to treat and potentially deadly. Disadvantaged populations such as the Indigenous people in remote tropical northern Australia have high burdens of S. pyogenes skin infection, and rheumatic heart disease. An effective vaccine would be a benefit, but none is approved for clinical use. We analysed data from 1810 S. pyogenes isolates from north Australia obtained over 28 years, to determine the potential of a previously described S. pyogenes vaccine candidate to be effective in this region. Only one quarter of the isolates from skin infections had a surface antigen corresponding to any one of the 30 antigen variants in the candidate vaccine. Previous work in animals indicates potential cross-protection from the vaccine against strains with mismatched antigens. However, even if this occurs in humans, protection against skin infection strains would likely remain compromised, unless there were additional components in the vaccine. Further studies on cross-protection are critical to defining the potential of this type of vaccine in populations burdened with S. pyogenes skin infections and rheumatic heart disease.

Post-streptococcal glomerulonephritis: Some reduction in a disease of disparities

AIM

A retrospective Auckland-wide (total population approximately 1.4 million) study of hospital admissions from 2007 to 2015 was conducted to assess trends in admissions for acute post-streptococcal glomerulonephritis (APSGN) in children aged 0-14 years.

METHODS

International Statistical Classification of Diseases (ICD10) discharge codes were used to identify potential cases of APSGN, and electronic clinical records and laboratory data were compared with established case definitions for definite or probable APSGN.

RESULTS

A total of 430 cases of APSGN were identified (definite n = 337, probable n = 93), with a mean annual incidence of 15.2/100 000 (95% confidence interval (CI) 14.9-15.6). Incidence (0-14 years) was 17 times higher in Pacific peoples (50.2/100 000, 95% CI 48.6-51.8) and almost 7 times higher in Māori (19.6/100 000, 95% CI 18.6-20.7) than European/other populations (2.9/100 000, 95% CI 2.7-3.1). Multivariate analysis found ethnicity, deprivation, male gender, age (peak 3-8 years) and season (summer/autumn) to be associated with admission risk. Admission rates showed a significant change of -9.0% (95% CI -10.4, 7.4%) per year, with 2011 being an exception. Low C3 complement, hypertension, elevated streptococcal titres, oedema and heavy proteinuria were present in 94, 65, 67, 52 and 49% of cases, respectively. Relying on ICD10 codes without further review of clinical notes would result in an overcount of cases by 25%.

CONCLUSIONS

There is severe disparity in APSGN admission rates, with a disproportionate burden of disease for Pacific and Māori children and those living in deprived circumstances. Rates trended downward from 2007 to 2015.

Factors associated with treatment outcome of acute post streptococcal glomerulonephritis among patients less than 18 years in Mekelle City, Public Hospitals, North Ethiopia

Objective

To assess factors associated treatment outcomes of acute post streptococcal glomerular nephritis among patients less than 18 years old in Mekelle City Public Hospitals.

Results

About 334 medical records c of children with acute post streptococcal glomerular nephritis were revised during the study period. Of these 244 (73.1%) had a positive outcome. acute post streptococcal glomerular nephritis was found to be statically significant associated with age < 5 years, duration of infection, the source of infection and length of stay in Hospital.

Ascertaining infectious disease burden through primary care clinic attendance among young Aboriginal children living in four remote communities in Western Australia

Infectious diseases contribute a substantial burden of ill-health in Australia’s Aboriginal children. Skin infections have been shown to be common in remote Aboriginal communities, particularly in the Northern Territory, Australia. However, primary care data on skin and other infectious diseases among Aboriginal children living in remote areas of Western Australia are limited. We conducted a retrospective review of clinic presentations of all children aged 0 to 5 years presenting to four clinics located in the Western Desert region of Western Australia between 2007 and 2012 to determine this burden at a local level. Infectious diseases accounted for almost 50% of all clinic presentations. Skin infections (sores, scabies and fungal infections) were the largest proportion (16%), with ear infections (15%) and upper respiratory infections (13%) also high. Skin infections remained high in all age groups; 72% of children presented at least once with skin infections. Scabies accounted for only 2% of all presentations, although one-quarter of children presented during the study for management of scabies. Skin sores accounted for 75% of the overall burden of skin infections. Improved public health measures targeting bacterial skin infections are needed to reduce this high burden of skin infections in Western Australia.

The current role for clinical and renal histological findings as predictor for outcome in Australian patients with lupus nephritis

Objectives To investigate the current demographic, clinical and histological characteristics of patients with lupus nephritis (LN) in Western Australia (WA) with regards to their predictive value for patient and renal outcome. Methods Retrospective study of adult systemic lupus erythematosus (SLE) patients with a first renal biopsy demonstrating LN between 1997 and 2017 at a metropolitan tertiary hospital in WA. Clinical data were collected at baseline and last follow-up with renal biopsy findings classified by International Society of Nephrology (ISN) criteria. Annual incidence rates (AIRs)/100,000, Kaplan-Meyer curves and Cox regression hazard ratio for independent predictors for patient and renal survival were applied. Results The AIR was 3.3, 3.1 and 0.4 for Asian ( n = 29), Indigenous Australian (IA) ( n = 11) and Caucasian ( n = 43) patients, respectively ( p < 0.01). There was no significant subgroup difference regarding ISN class (proliferative 66%, membranous 19%, mesangial 15%), levels of proteinuria (median PCR 300 mg/mmol) or frequency of raised creatinine (31%), anti-dsDNA antibody (89%) or hypocomplementaemia (88%). Treatment included corticosteroids (91%), cyclophosphamide (30%), mycophenolate (67%) and antihypertensive drugs (67%). Five- (81%) and 10-year (70%) survival was lower for IAs than for Caucasians and Asians (95% each at both time points) ( p = 0.016). Five- and 10-year renal survival (endpoint renal replacement therapy (RRT)) was 86% and 64% for IA vs 100% for Asian, 100% and 96% for Caucasian patients ( p = 0.02). IA background was the only independent predictor for poor patient survival and together with male gender also for renal survival. Only 25% of all patients remained free of any organ damage with non-renal damage observed in 53% of survivors. Conclusions LN incidence in WA was 0.75/100,000 with the lowest rate observed in Caucasians. While Asian patients have the same favourable outlook as Caucasians, the outcome is much bleaker for IA patients. Other clinical and histological findings did not predict outcomes, and importantly more than half of all surviving patients accrued non-renal damage.

Context-sensitive antibiotic optimization: a qualitative interviews study of a remote Australian hospital setting

BACKGROUND

Antibiotic optimization is an urgent international issue. Regulatory frameworks, including the requirement to have a functioning antimicrobial stewardship (AMS) programme, are now ubiquitous across the hospital sector nationally and internationally. However, healthcare is ultimately delivered in a diverse range of institutional settings and social contexts. There is emerging evidence that implementation of antibiotic optimization strategies may be inappropriate or even counterproductive to attempts to optimize in atypical healthcare settings.

AIM

To document the experiences and perspectives of clinical staff in a remote healthcare setting in Australia with respect to antimicrobial use, and strategies for optimization in that environment.

METHODS

Semi-structured qualitative interviews were conducted with 30 healthcare professionals, including doctors, nurses and pharmacists, from a remote hospital in Queensland, Australia.

FINDINGS

Four themes were identified from the analysis as key challenges to antibiotic optimization: (i) AMS as externally driven, and local knowledge sidelined; (ii) perceptions of heightened local population risks, treatment failure and the subsequent pressure to over-use of antimicrobials; (iii) interprofessional relationship dynamics including medical hierarchical structures perceived as a barrier to AMS; (iv) a clinical workforce dominated by transient locum staff and other process issues were perceived as significant barriers.

CONCLUSION

The perceptions of healthcare professionals in this site lead to the conclusion that antimicrobial regulations and practice improvement strategies more generally are unlikely to succeed if they fail to accommodate and respect the context of care, the resource and structural constraints of the setting, and the specificities of particular populations (and subsequent clinical 'know-how').

Patterns of paediatric emergency presentations to a tertiary referral centre in the Northern Territory

OBJECTIVE

To describe epidemiological data concerning paediatric attendances at the ED of Royal Darwin Hospital (RDH).

METHODS

We conducted a retrospective cohort study of paediatric emergency presentations to the RDH ED during 2004 and 2013. Epidemiological data, including demographics, admission rates and diagnostic grouping, were analysed using descriptive and comparative statistical methods. We compared data with findings from a baseline epidemiological study by the Paediatric Research in Emergency Departments International Collaborative (PREDICT) conducted in 2004.

RESULTS

A total of 12 745 and 15 378 paediatric presentations (age 0-18 years) to the RDH ED were analysed for the years 2004 and 2013 respectively. In 2004, the mean age of children presenting to RDH was 7.1 years, and 56.0% were female. Indigenous patients accounted for 31.2% of presentations at RDH and were significantly more likely to be admitted than non-Indigenous patients (31.6% vs 12.8%, OR 3.24, 95% CI 2.95-3.55). Children <5 years old accounted for the highest number of presentations (45.2%) and admissions (51.2%), and there was a high proportion of adolescent presentations (18.0%). Similar to the PREDICT study, viral infectious conditions (bronchiolitis, gastroenteritis, upper respiratory tract infections) were the most common cause for presentations. Key differences included a higher proportion of patients presenting with cellulitis and head injury at RDH and an increasing proportion of adolescent psychiatric presentations at RDH from 2004 to 2013.

CONCLUSION

This study provides important information regarding paediatric presentations to a major referral hospital in the Northern Territory. Overall, there was a disproportionate rate of presentation and admission among Indigenous children. Other key findings were higher proportions of cellulitis, head injury and adolescent presentations. These findings can assist in service planning and in directing future research specific to children in the Northern Territory.

M protein gene (emm type) analysis of group A Streptococcus isolates recovered during an acute glomerulonephritis outbreak in northern Western Australia

Certain M protein types of group A streptococcus (GAS) are known to cause acute post-streptococcal glomerulonephritis (APSGN). Outbreaks of APSGN can occur regularly in tropical regions but the emm types responsible are geographically and temporally diverse. GAS isolates from Western Australia (WA) were analysed for emm type and emm cluster during the period of increased APSGN activity in the tropical northern Kimberley region of WA. Although emm types 49, 75 and 108 and corresponding emm clusters E3, E6 and D4 were more common in WA during the outbreak there was no predominant circulating emm type or cluster found to correspond to the APSGN activity. This is consistent with the high diversity of GAS strains found during APSGN outbreaks in other countries. Potential vaccine coverage of the new 30-valent M-protein GAS vaccine was 70%.

Analysis of clinical presentation, pathological spectra, treatment and outcomes of biopsy-proven acute postinfectious glomerulonephritis in adult indigenous people of the Northern Territory of Australia

AIM

Acute postinfectious glomerulonephritis is common in indigenous communities in the Northern Territory, Australia. It is a major risk factor for the high prevalence of chronic kidney disease. We aimed to analyse the clinical presentation, pathological spectra, treatment and outcomes of biopsy-proven acute postinfectious glomerulonephritis in the Northern Territory.

METHODS

We performed a retrospective cohort analysis of all adult patients (≥18 years) who were diagnosed with acute postinfectious glomerulonephritis on native renal biopsies from 01/01/2004 to 31/05/2014. The outcome measure was end-stage renal disease requiring long-term dialysis.

RESULTS

Forty-three of 340 patients who had renal biopsies had acute postinfectious glomerulonephritis. Most were Aboriginals (88.4%). They had co-morbidities; diabetes mellitus (60.5%), hypertension (60.5%) and smoking (56.4%). Forty-nine per cent had multiple pathologies on biopsy. Predominant histological pattern was diffuse proliferative glomerulonephritis (72%). Main sites of infections were skin (47.6%) and upper respiratory tract infection (26.2%) with streptococcus and staphylococcus as predominant organisms. Fifty per cent of patients developed end-stage renal disease. On multivariable logistic regression analysis, those on dialysis had higher baseline creatinine (P = 0.003), higher albumin/creatinine ratio at presentation (P = 0.023), higher serum creatinine at presentation (P = 0.02) and lower estimated glomerular filtration rate at presentation (P = 0.012).

CONCLUSION

Overall, most patients had pre-existing pathology with superimposed acute postinfectious glomerulonephritis that led to poor outcomes in our cohort.

Are scabies and impetigo "normalised"? A cross-sectional comparative study of hospitalised children in northern Australia assessing clinical recognition and treatment of skin infections

BACKGROUND

Complications of scabies and impetigo such as glomerulonephritis and invasive bacterial infection in Australian Aboriginal children remain significant problems and the overall global burden of disease attributable to these skin infections remains high despite the availability of effective treatment. We hypothesised that one factor contributing to this high burden is that skin infection is under-recognised and hence under-treated, in settings where prevalence is high.

METHODS

We conducted a prospective, cross-sectional study to assess the burden of scabies, impetigo, tinea and pediculosis in children admitted to two regional Australian hospitals from October 2015 to January 2016. A retrospective chart review of patients admitted in November 2014 (mid-point of the prospective data collection in the preceding year) was performed. Prevalence of documented skin infection was compared in the prospective and retrospective population to assess clinician recognition and treatment of skin infections.

RESULTS

158 patients with median age 3.6 years, 74% Aboriginal, were prospectively recruited. 77 patient records were retrospectively reviewed. Scabies (8.2% vs 0.0%, OR N/A, p = 0.006) and impetigo (49.4% vs 19.5%, OR 4.0 (95% confidence interval [CI 2.1-7.7) were more prevalent in the prospective analysis. Skin examination was only documented in 45.5% of cases in the retrospective review. Patients in the prospective analysis were more likely to be prescribed specific treatment for skin infection compared with those in the retrospective review (31.6% vs 5.2%, OR 8.5 (95% CI 2.9-24.4).

CONCLUSIONS

Scabies and impetigo infections are under-recognised and hence under-treated by clinicians. Improving the recognition and treatment of skin infections by clinicians is a priority to reduce the high burden of skin infection and subsequent sequelae in paediatric populations where scabies and impetigo are endemic.

[Streptococcus pyogenes infection in paediatrics: from pharyngotonsillitis to invasive infections]

BACKGROUND

Streptococcus pyogenes or Group A Streptococci (GAS) cause many infections in infancy. Changes in its epidemiology have been described in recent years, including an increase in invasive infections (iGAS).

METHODS

A retrospective-descriptive study was conducted on children less than 15 years old, with GAS infections, in particular iGAS, and their complications from February 2004-April 2014.

RESULTS

A total of 2,192 positive cultures were obtained of which 92.7% were pharyngeal cultures. Twenty-nine patients were admitted to hospital: 4 with suppurative complications, 7 post-infective, 14 iGAS, and 4 probable iGAS cases. There were no differences in the frequency of GAS isolations/year. Non-invasive isolates were more frequent in winter and spring (P<.001), and 68.3% were in patients younger than 5 years. The incidence of iGAS was 2.1/100,000 children/year. There was no seasonality, and it was more frequent in younger children (P=.039). The most common diagnosis was pneumonia (6/14). Eight patients required intensive care. They were treated empirically with second or third-generation cephalosporin or with intravenous penicillin, and pneumonia required longer treatment times (P=.016). All GAS isolates were sensitive to penicillin, and 10.6% were resistant to erythromycin. The time spent in hospital was longer for iGAS than other cases (P=.028). No patients died.

CONCLUSIONS

Pharyngotonsillitis caused by GAS is common in childhood, and its incidence is increasing in children younger than 5 years. At the moment, post-infectious complications are rare. Invasive infections are the most severe forms of presentation, and are more common in younger children.

Streptococcal Immunity Is Constrained by Lack of Immunological Memory following a Single Episode of Pyoderma

The immunobiology underlying the slow acquisition of skin immunity to group A streptococci (GAS), is not understood, but attributed to specific virulence factors impeding innate immunity and significant antigenic diversity of the type-specific M-protein, hindering acquired immunity. We used a number of epidemiologically distinct GAS strains to model the development of acquired immunity. We show that infection leads to antibody responses to the serotype-specific determinants on the M-protein and profound protective immunity; however, memory B cells do not develop and immunity is rapidly lost. Furthermore, antibodies do not develop to a conserved M-protein epitope that is able to induce immunity following vaccination. However, if re-infected with the same strain within three weeks, enduring immunity and memory B-cells (MBCs) to type-specific epitopes do develop. Such MBCs can adoptively transfer protection to naïve recipients. Thus, highly protective M-protein-specific MBCs may never develop following a single episode of pyoderma, contributing to the slow acquisition of immunity and to streptococcal endemicity in at-risk populations.

GAS skin infections pose a significant health problem in the tropics. They are highly prevalent in developing countries as well as amongst the Indigenous populations of developed countries. In at-risk impoverished communities the epidemiology of GAS infections is very dynamic, leading to very high rates of streptococcal-associated serious pathology including rheumatic heart disease, glomerulonephritis and invasive GAS disease. Immunity to GAS takes over 20 years to develop and this has been attributed to sequence diversity of the type-specific surface M-protein. There are more than 250 different strains of GAS and it known that antibodies to the amino-terminal segment of the M-protein can kill organisms in a strain-specific manner in vitro. In the present study, using four different strains of GAS isolated from the skin lesions of Aboriginal patients in the Northern Territory of Australia, we make the discovery that skin infection does not induce long-lived type-specific immunity. However, following reinfection with the same strain memory B cells are generated and long-term strain-protective immunity then develops. The dependence on reinfection for the development of strain-specific immunity compounds with antigenic diversity of the M-protein and provides a rational explanation for the very slow acquisition of streptococcal immunity.

High Incidence of Invasive Group A Streptococcal Infections in Remote Indigenous Communities in Northwestern Ontario, Canada

Background

Worldwide, indigenous populations appear to be at increased risk for invasive group A streptococcal (iGAS) infections. Although there is empirical evidence that the burden of iGAS disease is significant among remote First Nations communities in Northwestern Ontario, Canada, the epidemiology of iGAS infections in the area remains poorly characterized.

Methods

Individuals that met case definition for iGAS disease and whose laboratory specimens were processed by Meno Ya Win Health Centre in Sioux Lookout, Canada or who were reported to Thunder Bay District Health Unit, Canada were identified for the period 2009 to 2014. Case demographics, clinical severity, comorbidities, and risk factors were collected through chart review. Strain typing and antibiotic susceptibility were determined when possible. Basic descriptive statistics were calculated.

Results

Sixty-five cases of iGAS disease were identified, for an annualized incidence of 56.2 per 100 000. Primary bacteremia was present in 26.2% of cases, and cellulitis was identified in 55.4% of cases. The most common comorbidities identified were diabetes (38.5%) and skin conditions (38.5%). Prevalent risk factors included alcohol dependence (25%). Fourteen different emm types were identified among 42 isolates, with the most common being emm114 (17.4%), emm11 (15.2%), and emm118 (13.0%). Resistance to erythromycin and clindamycin was found in 24.6% of isolates.

Conclusions

Rural and remote First Nations communities in Northwestern Ontario experience iGAS infections at a rate 10 times the provincial and national average. Compared with other North American series, a lower proportion of isolates causing infection were of emm types included in candidate GAS vaccines.

Reduced bacterial skin infections in HIV-infected African children randomized to long-term cotrimoxazole prophylaxis

OBJECTIVE

To evaluate whether cotrimoxazole prophylaxis prevents common skin conditions in HIV-infected children.

DESIGN

Open-label randomized controlled trial of continuing versus stopping daily cotrimoxazole (post-hoc analysis).

SETTING

Three sites in Uganda and one in Zimbabwe.

PARTICIPANTS

A total of 758 children aged more than 3 years receiving antiretroviral therapy (ART) for more than 96 weeks in the ARROW trial were randomized to stop (n = 382) or continue (n = 376) cotrimoxazole after median (interquartile range) 2.1(1.8, 2.2) years on ART.

INTERVENTION

Continuing versus stopping daily cotrimoxazole.

MAIN OUTCOME MEASURES

Nurses screened for signs/symptoms at 6-week visits. This was a secondary analysis of ARROW trial data, with skin complaints categorized blind to randomization as bacterial, fungal, or viral infections; dermatitis; pruritic papular eruptions (PPEs); or others (blisters, desquamation, ulcers, and urticaria). Proportions ever reporting each skin complaint were compared across randomized groups using logistic regression.

RESULTS

At randomization, median (interquartile range) age was 7 (4, 11) years and CD4 was 33% (26, 39); 73% had WHO stage 3/4 disease. Fewer children continuing cotrimoxazole reported bacterial skin infections over median 2 years follow-up (15 versus 33%, respectively; P < 0.001), with similar trends for PPE (P = 0.06) and other skin complaints (P = 0.11), but not for fungal (P = 0.45) or viral (P = 0.23) infections or dermatitis (P = 1.0). Bacterial skin infections were also reported at significantly fewer clinic visits (1.2 versus 3.0%, P < 0.001). Independent of cotrimoxazole, bacterial skin infections were more common in children aged 6-8 years, with current CD4 cell count less than 500 cells/μl, WHO stage 3/4, less time on ART, and lower socio-economic status.

CONCLUSION

Long-term cotrimoxazole prophylaxis reduces common skin complaints, highlighting an additional benefit for long-term prophylaxis in sub-Saharan Africa.

Protocol for the systematic review of the prevention, treatment and public health management of impetigo, scabies and fungal skin infections in resource-limited settings

BACKGROUND

Impetigo, scabies, and fungal skin infections disproportionately affect populations in resource-limited settings. Evidence for standard treatment of skin infections predominantly stem from hospital-based studies in high-income countries. The evidence for treatment in resource-limited settings is less clear, as studies in these populations may lack randomisation and control groups for cultural, ethical or economic reasons. Likewise, a synthesis of the evidence for public health control within endemic populations is also lacking. We propose a systematic review of the evidence for the prevention, treatment and public health management of skin infections in resource-limited settings, to inform the development of guidelines for the standardised and streamlined clinical and public health management of skin infections in endemic populations.

METHODS

The protocol has been designed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement. All trial designs and analytical observational study designs will be eligible for inclusion. A systematic search of the peer-reviewed literature will include PubMed, Excertpa Medica and Global Health. Grey literature databases will also be systematically searched, and clinical trials registries scanned for future relevant studies. The primary outcome of interest will be the clinical cure or decrease in prevalence of impetigo, scabies, crusted scabies, tinea capitis, tinea corporis or tinea unguium. Two independent reviewers will perform eligibility assessment and data extraction using standardised electronic forms. Risk of bias assessment will be undertaken by two independent reviewers according to the Cochrane Risk of Bias tool. Data will be tabulated and narratively synthesised. We expect there will be insufficient data to conduct meta-analysis. The final body of evidence will be reported against the Grades of Recommendation, Assessment, Development and Evaluation grading system.

DISCUSSION

The evidence derived from the systematic review will be used to inform the development of guidelines for the management of skin infections in resource-limited settings. The evidence derived will be intended for use by clinicians, public health practitioners and policy makers in the treatment of skin infections and the development of skin infection control programmes. The review will identify any gaps in the current evidence to provide direction for future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015029453.

Whole genome sequencing reveals extensive community-level transmission of group A Streptococcus in remote communities

Impetigo is common in remote Indigenous children of northern Australia, with the primary driver in this context being Streptococcus pyogenes [or group A Streptococcus (GAS)]. To reduce the high burden of impetigo, the transmission dynamics of GAS must be more clearly elucidated. We performed whole genome sequencing on 31 GAS isolates collected in a single community from children in 11 households with ⩾2 GAS-infected children. We aimed to determine whether transmission was occurring principally within households or across the community. The 31 isolates were represented by nine multilocus sequence types and isolates within each sequence type differed from one another by only 0-3 single nucleotide polymorphisms. There was evidence of extensive transmission both within households and across the community. Our findings suggest that strategies to reduce the burden of impetigo in this setting will need to extend beyond individual households, and incorporate multi-faceted, community-wide approaches.

Impetigo and scabies - Disease burden and modern treatment strategies

Impetigo and scabies both present different challenges in resource-limited compared with industrialised settings. Severe complications of these skin infections are common in resource-limited settings, where the burden of disease is highest. The microbiology, risk factors for disease, diagnostic approaches and availability and suitability of therapies also vary according to setting. Taking this into account we aim to summarise recent data on the epidemiology of impetigo and scabies and describe the current evidence around approaches to individual and community based treatment.

Mitochondrial Genome Sequence of the Scabies Mite Provides Insight into the Genetic Diversity of Individual Scabies Infections

The scabies mite, Sarcoptes scabiei, is an obligate parasite of the skin that infects humans and other animal species, causing scabies, a contagious disease characterized by extreme itching. Scabies infections are a major health problem, particularly in remote Indigenous communities in Australia, where co-infection of epidermal scabies lesions by Group A Streptococci or Staphylococcus aureus is thought to be responsible for the high rate of rheumatic heart disease and chronic kidney disease. We collected and separately sequenced mite DNA from several pools of thousands of whole mites from a porcine model of scabies (S. scabiei var. suis) and two human patients (S. scabiei var. hominis) living in different regions of northern Australia. Our sequencing samples the mite and its metagenome, including the mite gut flora and the wound micro-environment. Here, we describe the mitochondrial genome of the scabies mite. We developed a new de novo assembly pipeline based on a bait-and-reassemble strategy, which produced a 14 kilobase mitochondrial genome sequence assembly. We also annotated 35 genes and have compared these to other Acari mites. We identified single nucleotide polymorphisms (SNPs) and used these to infer the presence of six haplogroups in our samples, Remarkably, these fall into two closely-related clades with one clade including both human and pig varieties. This supports earlier findings that only limited genetic differences may separate some human and animal varieties, and raises the possibility of cross-host infections. Finally, we used these mitochondrial haplotypes to show that the genetic diversity of individual infections is typically small with 1–3 distinct haplotypes per infestation.

The scabies mite is a skin parasite that infects humans and other animal species, causing scabies, a contagious disease characterized by extreme itching. Scabies infections are a major health problem in developing countries and in indigenous Australian populations, where scabies is associated with pyoderma (skin sores) and linked to rheumatic fever and rheumatic heart disease. Little is known about the genetics of the scabies mite. We have assembled the mitochondrial genome of scabies mites obtained from human patients in Australia and from a pig model. While investigating the genetic diversity of each infestation, we found that mitochrondial genomes clustered into two broad clades and showed limited genetic diversity within each infestation. Remarkably, one closely related clade included both human and pig mites, suggesting that mite transmission from pig to human may be possible. This could have major implications in the management of porcine mange and human scabies.

Impact of an Ivermectin Mass Drug Administration on Scabies Prevalence in a Remote Australian Aboriginal Community

Background

Scabies is endemic in many Aboriginal and Torres Strait Islander communities, with 69% of infants infected in the first year of life. We report the outcomes against scabies of two oral ivermectin mass drug administrations (MDAs) delivered 12 months apart in a remote Australian Aboriginal community.

Methods

Utilizing a before and after study design, we measured scabies prevalence through population census with sequential MDAs at baseline and month 12. Surveys at months 6 and 18 determined disease acquisition and treatment failures. Scabies infestations were diagnosed clinically with additional laboratory investigations for crusted scabies. Non-pregnant participants weighing ≥15 kg were administered a single 200 μg/kg ivermectin dose, repeated after 2–3 weeks if scabies was diagnosed, others followed a standard alternative algorithm.

Principal Findings

We saw >1000 participants at each population census. Scabies prevalence fell from 4% at baseline to 1% at month 6. Prevalence rose to 9% at month 12 amongst the baseline cohort in association with an identified exposure to a presumptive crusted scabies case with a higher prevalence of 14% amongst new entries to the cohort. At month 18, scabies prevalence fell to 2%. Scabies acquisitions six months after each MDA were 1% and 2% whilst treatment failures were 6% and 5% respectively.

Conclusion

Scabies prevalence reduced in the six months after each MDA with a low risk of acquisition (1–2%). However, in a setting where living conditions are conducive to high scabies transmissibility, exposure to presumptive crusted scabies and population mobility, a sustained reduction in prevalence was not achieved.

Clinical Trial Registration

Australian New Zealand Clinical Trial Register (ACTRN—12609000654257).

Scabies is endemic in many Australian Aboriginal and Torres Strait Islander communities, with 69% of infants infected in the first year of life. Previous mass drug administration (MDA) programs using topical acaricides to decrease scabies prevalence have had varying degrees of success in Australia. We were invited by one community in eastern Arnhem Land to develop and deliver an oral-ivermectin MDA. Utilizing a before and after study design, we measured scabies prevalence through population census with sequential MDAs at baseline and month 12. Scabies prevalence fell from 4% at baseline to 1% at month 6, rising to 9% at month 12 in association with an identified exposure to a presumptive crusted scabies case. For new entries to the cohort at month 12 scabies prevalence was higher at 14%. We were able to demonstrate a reduction in scabies prevalence in the six months after each MDA with a low risk of acquisition (1–2%); however, a sustained reduction was not achieved.

High burden of invasive group A streptococcal disease in the Northern Territory of Australia

Although the incidence of invasive group A streptococcal disease in northern Australia is very high, little is known of the regional epidemiology and molecular characteristics. We conducted a case series of Northern Territory residents reported between 2011 and 2013 with Streptococcus pyogenes isolates from a normally sterile site. Of the 128 reported episodes, the incidence was disproportionately high in the Indigenous population at 69·7/100 000 compared to 8·8/100 000 in the non-Indigenous population. Novel to the Northern Territory is the extremely high incidence in haemodialysis patients of 2205·9/100 000 population; and for whom targeted infection control measures could prevent transmission. The incidences in the tropical north and semi-arid Central Australian regions were similar. Case fatality was 8% (10/128) and streptococcal toxic shock syndrome occurred in 14 (11%) episodes. Molecular typing of 82 isolates identified 28 emm types, of which 63 (77%) were represented by four emm clusters. Typing confirmed transmission between infant twins. While the diverse range of emm types presents a challenge for effective coverage by vaccine formulations, the limited number of emm clusters raises optimism should cluster-specific cross-protection prove efficacious. Further studies are required to determine effectiveness of chemoprophylaxis for contacts and to inform public health response.

The Global Epidemiology of Impetigo: A Systematic Review of the Population Prevalence of Impetigo and Pyoderma

Objective

We conducted a comprehensive, systematic review of the global childhood population prevalence of impetigo and the broader condition pyoderma.

Methods

PubMed was systematically searched for impetigo or pyoderma studies published between January 1 1970 and September 30 2014. Two independent reviewers extracted data from each relevant article on the prevalence of impetigo.

Findings

Sixty-six articles relating to 89 studies met our inclusion criteria. Based on population surveillance, 82 studies included data on 145,028 children assessed for pyoderma or impetigo. Median childhood prevalence was 12·3% (IQR 4·2–19·4%). Fifty-eight (65%) studies were from low or low-middle income countries, where median childhood prevalences were 8·4% (IQR 4·2–16·1%) and 14·5% (IQR 8·3–20·9%), respectively. However, the highest burden was seen in underprivileged children from marginalised communities of high-income countries; median prevalence 19·4%, (IQR 3·9–43·3%).

Conclusion

Based on data from studies published since 2000 from low and low-middle income countries, we estimate the global population of children suffering from impetigo at any one time to be in excess of 162 million, predominantly in tropical, resource-poor contexts. Impetigo is an under-recognised disease and in conjunction with scabies, comprises a major childhood dermatological condition with potential lifelong consequences if untreated.