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

Abstract

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.

Latency, Anti-Bacterial Resistance Pattern, and Bacterial Infection–Related Glomerulonephritis

“…Thirty-three percent of the cohort had parainfectious GN, and this led to an overall shorter median latent period in our study than reported elsewhere (6,7,11,34). The majority of patients with parainfectious GN had lung and urinary tract infections, caused by nonstreptococcal bacteria, whereas postinfectious GN followed upper respiratory tract and skin infections predominantly caused by streptococcal bacteria and had longer latency as in other studies (4,13,(35)(36)(37)(38)(39). The variability in latency is probably due to the type and virulence of the infecting organism and intrinsic host factors.…”

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

“…However, the burden of disease can differ significantly between ethnic groups. For example, immune-mediated GAS diseases almost exclusively affect Indigenous Maori and Pacific peoples in NZ (Oliver et al, 2017;Vogel et al, 2019). These differences should be considered when generalizing the results of this study to different settings, or estimating the potential reduction in burden by a vaccine targeting at-risk populations.…”

“…APSGN can contribute to chronic renal failure (Hoy et al, 2012;Marshall et al, 2011). While ARF and APSGN are now rare in most high-income countries, these diseases have persisted in socially disadvantaged populations, including in Maori and Pacific communities in NZ (Oliver et al, 2017;Vogel et al, 2019).…”

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

“…A follow-up study from 2005 to 2017 reviewing admission rates for PSGN showed that Māori children still had 7 times the risk of admission compared to children of European/Other ethnicity despite rates of admission trending downward by 9% per year. Multivariate analysis models including ethnicity and deprivation suggest that part of the risk conferred by ethnicity may be directly related to deprivation [19]. A study published in 2009, reviewed all cases of PSGN severe enough to require a renal biopsy over the span of 12 years, found that Māori represented 41% of these cases [20].…”