The Emergence and Impact of the M1 Lineage on Invasive Group A Streptococcus Disease in Aotearoa New Zealand.

M1 is associated with current surges in invasive infection globally, partly due to increased production of superantigen streptococcal pyrogenic exotoxin A. We show that M1 is now the dominant invasive 1 lineage in Aotearoa New Zealand and is genomically related to community infections, suggesting that measures that effectively prevent group A pharyngitis in children could reduce invasive disease.

Cytokine imbalance in acute rheumatic fever and rheumatic heart disease: Mechanisms and therapeutic implications.

Acute Rheumatic Fever (ARF) and Rheumatic Heart Disease (RHD) are autoimmune sequelae of Group A Streptococcus infection with significant global disease burden. The pathogenesis of these diseases is poorly understood, and no immune modulating therapies are available to stop progression from ARF to RHD. Cytokines and chemokines are immune signaling molecules critical to the development of autoimmune diseases.

Whole genome sequencing and molecular epidemiology of paediatric Staphylococcus aureus bacteraemia.

Objectives: The role Staphylococcus aureus antimicrobial resistance genes and toxins play in disease severity, management and outcome in childhood is an emerging field requiring further exploration.

Methods: A prospective multisite study of Australian and New Zealand children hospitalised with S. aureus bacteraemia (SAB) occurred over 24 months (2017-2018).

Pediatric Staphylococcus aureus Bacteremia: Clinical Spectrum and Predictors of Poor Outcome.

Background: Staphylococcus aureus is a common cause of bacteremia, yet the epidemiology and predictors of poor outcome remain inadequately defined in childhood.

Methods: ISAIAH (Invasive Staphylococcus aureus Infections and Hospitalizations in children) is a prospective, cross-sectional study of S. aureus bacteremia (SAB) in children hospitalized in Australia and New Zealand over 24 months (2017-2018).

Comprehensive analysis of SARS-CoV-2 antibody dynamics in New Zealand.

Objectives: Circulating antibodies are important markers of previous infection and immunity. Questions remain with respect to the durability and functionality of SARS-CoV-2 antibodies. This study explored antibody responses in recovered COVID-19 patients in a setting where the probability of re-exposure is effectively nil, owing to New Zealand's successful elimination strategy.

Collaborative networks enable the rapid establishment of serological assays for SARS-CoV-2 during nationwide lockdown in New Zealand.

Background: Serological assays that detect antibodies to SARS-CoV-2 are critical for determining past infection and investigating immune responses in the COVID-19 pandemic. We established ELISA-based immunoassays using locally produced antigens when New Zealand went into a nationwide lockdown and the supply chain of diagnostic reagents was a widely held domestic concern. The relationship between serum antibody binding measured by ELISA and neutralising capacity was investigated using a surrogate viral neutralisation test (sVNT).

Normal echocardiographic mitral and aortic valve thickness in children.

Objective: We aimed to define the normal range of aortic and mitral valve thickness in healthy schoolchildren from a high prevalence rheumatic heart disease (RHD) region, using a standardised protocol for imaging and measurement.

Methods: Measurements were performed in 288 children without RHD. Anterior mitral valve leaflet (AMVL) thickness measurements were performed at the midpoint and tip of the leaflet in the parasternal long axis (PSLA) in diastole, when the AMVL was approximately parallel to the ventricular septum.

Acute Rheumatic Fever After Group A Streptococcus Pyoderma and Group G Streptococcus Pharyngitis.

A case of acute rheumatic fever (ARF) in an Indigenous Maori child in New Zealand after Group A Streptococcus pyoderma and Group G Streptococcus pharyngitis is reported. The case demonstrates that ARF can develop in the absence of GAS pharyngitis and highlights a need for further research into the role of pyoderma and non-Group A Streptococci infections in ARF pathogenesis.

Valvular Regurgitation Using Portable Echocardiography in a Healthy Student Population: Implications for Rheumatic Heart Disease Screening.

Background: There is increasing use of portable echocardiography as a screening test for rheumatic heart disease (RHD). The prevalence of valvular regurgitation in healthy populations as determined using portable echocardiography has not been well defined. Minimal echocardiographic criteria for RHD have recently been clarified, but the overlap of normal and abnormal valvular regurgitation warrants further study.

When to start, what to start and other treatment controversies in pediatric HIV infection.

Over the last decade there have been dramatic changes in the management of pediatric HIV infection. Whilst observational studies and several randomized control trials (RCTs) have addressed some questions about when to start antiretroviral therapy (ART) in children and what antiretrovirals to start, many others remain unanswered. In infants, early initiation of ART greatly reduces mortality and disease progression.

Optimising echocardiographic screening for rheumatic heart disease in New Zealand: not all valve disease is rheumatic.

Aims: Echocardiography detects a greater prevalence of rheumatic heart disease than heart auscultation. Echocardiographic screening for rheumatic heart disease combined with secondary prophylaxis may potentially prevent severe rheumatic heart disease in high-risk populations. We aimed to determine the prevalence of rheumatic heart disease in children from an urban New Zealand population at high risk for acute rheumatic fever.