Keeping watch for strep A

As viruses circulate, conditions are ideal for secondary infections, Australian experts warn.

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Australian experts are monitoring the strep A situation after at least 16 children have died in the UK from complications of Group A streptococcus. 

“We’ve not seen the same surge here and we wouldn’t expect to at the same time,” Professor Robert Booy, Sydney infectious diseases paediatrician, told The Medical Republic.  

“But I think we could easily get a surge next year.” 

The UK has seen 4622 scarlet fever cases this year alone, a massive jump from the annual average of 1294 over the last five years. There’s also been 509 notifications of Invasive Group A Streptococcal disease, up from a yearly average of 248 cases, according to the latest UK Health Security Agency report. 

The condition commonly causes impetigo, strep throat, cellulitis and scarlet fever and sometimes leads to serious complications include pneumonia, meningitis, acute post-streptococcus glomerulonephritis, acute rheumatic fever and rheumatic heart disease. Invasive Group A streptococcal infection is less common. 

Professor Booy said the UK was experiencing a surge in late autumn and early winter respiratory infections, and Strep A outbreaks commonly happen on the back of an uptick in other infections. 

“Preceding viral infections, like influenza and other respiratory diseases, set up fertile ground for Strep A to come in secondarily,” Professor Booy, head of clinical research at the National Centre for Immunisation Research and Surveillance, explained. 

Invasive Group A Streptococcal occurs when strep A infects a normally sterile site, like the chest, bloodstream, tissue, or more rarely the brain. It can result in serious conditions including toxic shock syndrome and necrotising fasciitis. According to existing data, Australia has a minimum national paediatric incidence of 1.63 in 100,000 children overall.  

Prior covid infection is being explored as a potential cause for the UK outbreak, but Professor Booy said flu was a more likely reason.  

“We’ve been following covid for three years for secondary bacterial infections. There’s only a small predisposition from covid, not a strong one,” he said. 

There was an increase of invasive strep A in Australia in 2017/18 with the increased flu season, Associate Professor Nigel Crawford from the Murdoch Children’s Research Institute told The Medical Republic.  

While the condition was already a notifiable disease in various states, it was added to the national notifiable disease list in Australia in 2021. It is also monitored by PAEDS (pediatric active enhanced disease surveillance) which collects data on severe viral and bacterial infections in major children’s hospitals across country. 

“The numbers really dropped in 2020/2021. It was still seen, but not to the same level. As we’ve opened up viral infections are circulating and we therefore see more invasive disease,” Professor Crawford said. 

“It’s not covid that’s necessarily driving this infection; it’s other viruses.” 

Flu, RSV, adenovirus and enterovirus are currently circulating, said Professor Crawford. “It’s certainly possible that the general circulation of all of these viruses will increase the amount of invasive group A strep, which we will continue to monitor,” he said. 

Infectious diseases researchers are also closely watching for secondary infections in Indigenous communities. Strep A is more commonly carried in Indigenous children in rural settings where there is often poverty, crowded living situations and limited access to healthcare. It can lead to acute rheumatic fever and rheumatic heart disease. Rates of death from rheumatic heart disease in Indigenous people are among the highest in the world.  

Northern Territory Health issued an alert at the end of September this year about an increase in Group A Streptococcal diseases. “With high rates of Group A Streptococcus circulating in the NT, clinicians need to be … promoting hand washing, increasing skin hygiene and prompt treatment of sore throats (‘strep throat’), skin sores, and scabies. For individuals already on secondary prophylaxis for prevention of recurrent acute rheumatic fever episodes, supporting their timely and consistent prophylactic treatment is essential,” the department said. 

Clinicians were also urged to look for signs of acute post-streptococcal glomerulonephritis in children. Signs include puffy faces, sores or dark coloured urine, and doctors are advised to check for sudden increase in weight or blood pressure, blood or protein in the urine and oedema. 

“This infection doesn’t always present as classically as the other [Invasive Group A streptococcal] diseases,” Professor Crawford said. “It can be a little harder to pick than meningococcal disease, for example. They may not look quite as sick the very first time you see them. It might take longer for it to become clear that the child is very unwell.” 

Professor Nigel Crawford said an awareness of possible severe infection was the best way to pick up any related problems.  

“So observation of the child initially in terms of their parameters when they’re examined – what’s their heart rate compared to healthy children of the same age, how they’re looking from a hydration and temperature point of view. 

“That can be hard to tell just from the first time you observe them, but it’s important to follow up if you have ongoing concerns,” he said.  

Prophylactic treatment for household members is currently being deliberated at a national level, Professor Crawford told TMR. But the Royal Children’s Hospital in Melbourne already has clinical guidelines for management of household contacts of children with the invasive infection. 

“Secondary cases can and do occur, even if they’re at low rates,” Professor Crawford said. “The RCH guideline talks through the rationale [of prophylactic treatment] and what we would recommend.”