An unseasonal spike in severe strep A cases in Australia has prompted calls for a vaccine to prevent the deadly infection.
The number of children admitted to hospital with strep A rose from 23 in 2020 to 107 in 2022, the Murdoch Children's Research Institute found.
The children experienced symptoms including toxic shock syndrome and aggressive skin infections.
The strep A spike in Australia mirrored a similar rise in the northern hemisphere, despite the differences in seasons.
"This increase is likely due to a combination of environmental factors and viruses in circulation," the institute's Dr Yara-Natalie Abo said.
"More research is needed into whether new strains might be responsible."
Strep A causes sore throats, scarlet fever and skin sores, affecting about 750 million people globally and killing 500,000 a year.
The bacteria disproportionately affects young children, the elderly, pregnant women and Indigenous Australians.
There is currently no vaccine to prevent strep A but researchers are working towards an effective and accessible one.
"We hope this research will accelerate the development of a vaccine and move things forward to bigger field trials," the institute's Professor Andrew Steer said.
"A vaccine for strep A will save hundreds of thousands of lives every year and prevent millions of infections that send children and adults to the hospital or doctor."
