A new study analysing data from the has found that Australia experienced a significant surge in severe group A streptococcal disease (‘Strep A’) cases, similar to the northern hemisphere wave, in 2022, despite differences in seasons and circulating respiratory viruses.
The national research project – the results of which were published recently in The Lancet Regional Health – Western Pacific – highlights how the unseasonal increase in case load across the southern hemisphere adds evidence to the need for a safe and effective vaccine against Strep A.
Strep A infections disproportionately affect young children, elderly people, pregnant women, and Aboriginal and Torres Strait Islander people. Rates of acute rheumatic fever and rheumatic heart disease among Indigenous populations in northern Australia are some of the highest in the world. Currently, there is no vaccine available to prevent Strep A.
The PAEDS network collected data of children aged under 18 years who had been admitted to five major Australian paediatric hospitals with severe Strep A infections. They found that severe Strep A in Australian children increased sharply from mid-2022, following a reduction in cases during 2020 and 2021, and that cases jumped from 23 in 2020 to 107 by 2022. The incidence rate among Aboriginal and Torres Strait Islander children was twice that of non-Indigenous children.
Strep A infections affect around 750 million people and kill more than 500,000 globally every year – more than influenza, typhoid or whooping cough. Streptococcal A bacteria generally cause mild disease such as sore throats and skin sores (impetigo) – however, they can also cause invasive Group A streptococcal disease (iGAS), which includes septicaemia and meningitis; other serious diseases such as toxic shock syndrome and necrotising fasciitis; and post-streptococcal infection issues including rheumatic heart disease and kidney disease.
Increases in Strep A cases have been reported around the world, both during and outside of typical spring peaks, the researchers said. This is likely due to a combination of environmental factors and viruses in circulation; further research is needed to determine whether new strains might be responsible. It was also noted that reduced social contact during the COVID-19 pandemic may have impacted children’s immunity to Strep A.
More research is required into the causes of this spike and how we can prevent future surges.
