Public Health experts say there’s an increase worldwide in severe infections involving group A streptococcus and they are calling for it to be made a notifiable condition in New Zealand.
Group A streptococcus (GAS) is a common cause of sore throats and skin infections in children but in rare cases the bacteria can invade deeper into the body causing severe, life-threatening invasive GAS (iGAS).
In a Briefing published today by the Public Health Communication Centre, Dr Julie Bennett from the University of Otago, Wellington says despite the emerging threat, New Zealand is an outlier amongst high income countries as iGAS is not notifiable here.
“Data on the rate of infection is patchy in Aotearoa. We know it doubled between 2002 and 2016 to 9 infections per 100,000 people. The numbers are likely to be climbing now going by international figures which are showing iGAS cases jumping to several times higher than pre-pandemic levels.”
While some people carry the bacteria in the throat with no symptoms, Strep A can cause a range of diseases. Some will get sore throats and skin infections. But for others the invasive disease can lead to blood poisoning, pneumonia and necrotizing fasciitis. It can also result in scarlet fever, toxic shock syndrome and rheumatic fever.
“Early recognition, diagnosis, and correct treatment can be lifesaving,” says Dr Bennett. Making iGAS notifiable would also help with surveillance by providing a more complete record of cases.”
Mandatory reporting and genetic sequencing of iGAS-causing bacteria would also help keep track of the strains circulating and identify potential outbreaks. Recently Australia reported a new variant, M1UK, circulating there. “This variant was initially identified in the UK and has been linked to scarlet fever surges, and a marked increase in invasive infections. It is likely this variant is also circulating in NZ,” says Assoc Prof Nikki Moreland an immunologist from the University of Auckland and a co-author of the Briefing article.
Māori and Pacific populations suffer rates between four and seven times higher than NZ Europeans for GAS skin infections, acute rheumatic fever, and iGAS. Infants and the elderly are at particular high risk.
The NZ government has invested $10 million to facilitate the development of a vaccine to prevent GAS-related diseases. The Health Research Council of NZ has also supported world-leading research on risk factors for GAS infections.
“The next logical step for New Zealand is to conduct intervention studies to investigate the likely modes of transmission and how this infection can be prevented. Such studies could look at measures such as reducing crowding, adequate indoor ventilation, and intensive treatment of infections in settings such as homes and schools.” says Prof Michael Baker, an epidemiologist and co-author of the paper.
You can read the full Public Health Expert Briefing here.