Early diagnosis of acute rheumatic fever and rheumatic heart disease as part of a secondary prevention strategy: Narrative review

Mucosal Immunization Has Benefits over Traditional Subcutaneous Immunization with Group A Streptococcus Antigens in a Pilot Study in a Mouse Model

Group A Streptococcus (GAS) is a major human pathogen for which there is no licensed vaccine. To protect against infection, a strong systemic and mucosal immune response is likely to be necessary to prevent initial colonization and any events that might lead to invasive disease. A broad immune response will be necessary to target the varied GAS serotypes and disease presentations. To this end, we designed a representative panel of recombinant proteins to cover the stages of GAS infection and investigated whether mucosal and systemic immunity could be stimulated by these protein antigens. We immunized mice sublingually, intranasally and subcutaneously, then measured IgG and IgA antibody levels and functional activity through in vitro assays. Our results show that both sublingual and intranasal immunization in the presence of adjuvant induced both systemic IgG and mucosal IgA. Meanwhile, subcutaneous immunization generated only a serum IgG response. The antibodies mediated binding and killing of GAS cells and blocked binding of GAS to HaCaT cells, particularly following intranasal and subcutaneous immunizations. Further, antigen-specific assays revealed that immune sera inhibited cleavage of IL-8 by SpyCEP and IgG by Mac/IdeS. These results demonstrate that mucosal immunization can induce effective systemic and mucosal antibody responses. This finding warrants further investigation and optimization of humoral and cellular responses as a viable alternative to subcutaneous immunization for urgently needed GAS vaccines.

Addressing rheumatic fever inequities in Aotearoa New Zealand: a scoping review of prevention interventions

Introduction Rheumatic fever is a preventable illness caused by untreated Group A Streptococcus (GAS) infection. Despite reductions in most high-income countries, rheumatic fever rates remain a concern in Aotearoa New Zealand. Pacific and Māori people are inequitably affected, with risk of initial hospitalisation due to rheumatic fever 12- and 24-fold more likely, respectively, compared to non-Māori and non-Pacific people. Aim This scoping review aims to explore the range of interventions and initiatives in New Zealand seeking to prevent GAS and rheumatic fever, with a particular focus on Pacific and Māori. Methods Databases Scopus, Medline, EMBASE and CINAHL, along with grey literature sources, were searched to broadly identify interventions in New Zealand. Data were screened for eligibility and the final articles were charted into a stocktake table. Results Fifty-eight studies were included, reporting 57 interventions. These targeted school-based throat swabbing, awareness and education, housing, secondary prophylaxis, improving primary care guidelines and diagnosis of sore throats and skin infections. Some interventions reported short-term outcomes of improvements in awareness, a reduction in rheumatic fever risk and fewer hospitalisations. Evaluation outcomes were, however, lacking for many initiatives. Pacific and Māori people primarily served only in an advisory or delivery capacity, rather than as partners in co-design or leadership from the beginning. Discussion Although positive outcomes were reported for some interventions identified in this review, rheumatic fever rates have not shown any long-term reduction over time. Co-designing interventions with affected communities could ensure that strategies are better targeted and do not contribute to further stigma.

Medical Treatment for Rheumatic Heart Disease: A Narrative Review

BACKGROUND

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are rare in high-income countries; however, in Aotearoa New Zealand ARF and RHD disproportionately affect Indigenous Māori and Pacific Peoples. This narrative review explores the evidence regarding non-surgical management of patients with clinically significant valve disease or heart failure due to RHD.

METHODS

Medline, EMBASE and Scopus databases were searched, and additional publications were identified through cross-referencing. Included were 28 publications from 1980 onwards.

RESULTS

Of the available interventions, improved anticoagulation management and a national RHD register could improve RHD outcomes in New Zealand. Where community pharmacy anticoagulant management services (CPAMS) are available good anticoagulation control can be achieved with a time in the therapeutic range (TTR) of more than 70%, which is above the internationally recommended level of 60%. The use of pharmacists in anticoagulation control is cost-effective, acceptable to patients, pharmacists, and primary care practitioners. There is a lack of local data available to fully assess other interventions; including optimal therapy for heart failure, equitable access to specialist RHD care, prevention, and management of endocarditis.

CONCLUSION

As RHD continues to disproportionately affect Indigenous and minority groups, pro-equity tertiary prevention interventions should be fully evaluated to ensure they are reducing disease burden and improving outcomes in patients with RHD.