The alarming rise of invasive group A streptococcal

Researchers have called for better surveillance data in the fight against the rising invasive group A streptococcal infection epidemic.

Comprehensive surveillance data of invasive group A streptococcal infections in Australia is needed to support the development of a vaccine, according to a perspective published in the Medical Journal of Australia today.

Invasive group A streptococcal infections have been rising rapidly in the wake of easing restrictions from the coronavirus disease 2019 (COVID-19) pandemic.

Predominantly affecting children, group A streptococcal infections include sepsis, streptococcal toxic shock syndrome, necrotising fasciitis, pneumonia/empyema, bacteraemia and post partum endometritis.

Infections can lead to long term health conditions such as acute rheumatic fever and rheumatic heart disease.

The causes of the sharp rise in group A streptococcal infections since 2022 are uncertain, but may be related to the surge in respiratory viral infections following the easing of COVID-19 restrictions, especially in children.

Filling the clinical gaps

Lead article author, infectious diseases physician and doctoral researcher Dr Thel Hla told InSight+ that critical clinical gaps remain in the pursuit of national evidence-based guidelines.

“What we mean by clinical gaps is that, for example, even though there is evidence to suggest that close contacts of people with invasive Strep A are at increased risk of developing invasive disease themselves, there is still uncertainty about who benefits from receiving chemoprophylaxis and how rigorous the contact tracing needs to be,” Dr Hla said.

“As a result, there are wide variations in how each local public health unit handles invasive Strep A.

“There is also variation in clinical practice across Australia, with many paediatric hospitals offering chemoprophylaxis to family members whilst this is less consistent in general hospitals.

“More research is urgently needed to understand this issue and national clinical trials designed to guide decision making should be funded.”

A tale of two epidemics

Group A streptococcal infections disproportionally affect Aboriginal and Torres Strait Islander peoples, particularly in Northern Australia and the Kimberly region of Western Australia. This is likely due to the increased rate of skin infections in these populations.

Dr Hla told InSight+ the current dataset on infections is not disaggregated by Aboriginal and Torres Strait Islander status, which complicates efforts to understand the epidemiology of this disease.

“While there was media coverage about the high burden of invasive Strep A being found in the eastern states, there is a parallel long running endemic burden of disease in Northern Australia and for Aboriginal and Torres Strait Islander Australians that was not being talked about,” Dr Hla said.

“We felt that exploring the epidemiology of these two parallel epidemics was critical to providing the advice that Australian clinicians need.”

Dr Hla hopes that Aboriginal and Torres Strait Islander status will be included in the national notifiable dataset.

“From this, we will be able to glean a better general understanding of the impact invasive Strep A has on the population as a whole which can guide where our efforts should go and what other measures we should be explored for prevention (eg, vaccine development).”

Developing national guidelines

The Communicable Diseases Network of Australia (CDNA) is close to finalising a series of national guidelines for group A streptococcal infections.

“It will go a long way towards streamlining the collective efforts and allowing us to assess if our approaches are working” Dr Hla told InSight+.

“A proactive package of research on the epidemiology of invasive disease, transmission and treatment would better inform clinical recommendations in the Australian context, and prepare for the introduction of a Strep A vaccine when it becomes available.

Dr Hla is hopeful that global efforts to develop a group A streptococcal vaccine will be successful.

“Australia is leading the world in Strep A vaccine development, so having [national guidelines] occur in parallel to vaccine development will provide reassurance and evidence when it comes time for a new vaccine to be included.”

Read the Perspective in the Medical Journal of Australia

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