Time to address the neglected burden of group A Streptococcus

To the Editor: The toll of group A Streptococcus is dramatically unappreciated, despite increasing evidence of its burden.1 In Australia and New Zealand, we recently demonstrated that group A streptococcal throat and skin infections cause a sizable burden at the population level — cellulitis is the main contributor to the total burden of all group A streptococcal diseases and acute rheumatic fever and rheumatic heart disease contribute disproportionately relative to their frequency of occurrence.2,3

At a global level, the burden of group A Streptococcus is not abating. Global Burden of Disease data suggest that incident cases and deaths due to rheumatic heart disease alone have surpassed those of meningitis (Box). In 2019, more than 85% of rheumatic heart disease cases occurred among people aged under 35 years.4 No other group A streptococcal‐specific endpoints are available from the Global Burden of Disease data, yet all‐cause cellulitis was ranked the 24th most frequently occurring condition in high income countries in 2019.4 Group A Streptococcus causes outbreaks of poststreptococcal glomerulonephritis, contributing to the burden of chronic renal disease, and it is estimated to be the fifth most lethal pathogen on the planet, behind the human immunodeficiency virus (HIV), Mycobacterium tuberculosis, Plasmodium falciparum and S. pneumoniae, yet expenditure on vaccine development is only 0.17% of that spent on vaccines for HIV infection, malaria and tuberculosis.5

The divergence in numbers of cases and deaths due to group A Streptococcus compared with meningitis partially demonstrates the value of vaccination. Another major benefit of vaccination is a substantial reduction in antibiotic consumption. Indeed, pharyngitis is a major driver of antibiotic consumption globally, and an estimated 17% of antibiotic prescriptions for pharyngitis among children in the United States could be prevented by a group A Streptococcus vaccine.6

Two major initiatives aim to progress vaccine development. The Australian Strep A Vaccine Initiative (ASAVI) and the Strep A Vaccine Global Consortium (SAVAC) are addressing technical and investment barriers and leading at least one of the current vaccine candidates to an efficacy trial for pharyngitis prevention by 2024.5 An effective vaccine may prevent health and economic burdens due to the full range of group A streptococcal diseases and associated antibiotic consumption.

Box – Estimated number of new cases (left) and deaths (right) due to meningitis and rheumatic heart disease globally*

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* Data obtained from the Global Burden of Disease study 2019.4