Key messages
- From 1 March 2024, invasive group A streptococcal disease (iGAS) will become an urgent notifiable condition for medical practitioners and pathology services in Victoria.
- iGAS is a severe, invasive disease caused by infection with Streptococcus pyogenes, also known as Group A Streptococcus.
- iGAS can present as bacteraemia/septicaemia, necrotising fasciitis, streptococcal toxic shock syndrome or other serious illnesses which are associated with high morbidity and mortality.
- Diagnosis of iGAS relies on the laboratory detection of Streptococcus pyogenes and clinical information.
- Medical practitioners and pathology services must notify cases of iGAS immediately upon diagnosis to the Department of Health. Pathology services must also provide written notification within 5 working days.
What is the issue?
The Public Health and Wellbeing Act 2008 requires that prescribed conditions and micro-organisms are notified to the Department of Health. This law exists to monitor, prevent and control the occurrence of infectious diseases and other specified conditions to protect the Victorian community from further illness.
From 1 March 2024, invasive group A streptococcal disease (iGAS) will become an urgent notifiable condition for both medical practitioners and pathology services in Victoria.
Making iGAS an urgent notifiable condition enables public health response actions to be initiated more promptly and facilitates the collection of more comprehensive and accurate surveillance data.
iGAS is caused by infection with Streptococcus pyogenes, also known as Group A Streptococcus. It can present as bacteraemia/septicaemia, necrotising fasciitis, streptococcal toxic shock syndrome, empyema, meningitis, osteomyelitis, septic arthritis, puerperal sepsis or other severe, invasive diseases. These conditions can be life-threatening or lead to serious complications and disability.
Who is at risk?
The overall risk of iGAS in the general population is low. Young children, older people, and Aboriginal and Torres Strait Islander peoples are disproportionately impacted by iGAS.
The risk of iGAS is also higher in birthing parent-neonatal pairs, household or household-like contacts of someone with iGAS, and institutional settings such as residential aged care, disability care, child care, hospitals, prison, military barracks or similar settings.
Diagnosis
Diagnosis of iGAS relies on laboratory evidence of Streptococcus pyogenes in appropriate specimens and clinical presentation, as outlined in the table below:
| Case definition | Case criteria | Expected notification |
|---|---|---|
| Confirmed case |
Confirmed cases of iGAS are designated based on definitive laboratory evidence. This means the isolation or detection of Streptococcus pyogenes by culture or nucleic acid testing from a normally sterile site. Normally sterile site includes: • blood, cerebrospinal fluid, peritoneal fluid, pericardial fluid, joint fluid, bone, or bone marrow. • internal organs; specimens obtained from surgery or aspirate from one of the following: lymph node, brain, heart, liver, spleen, vitreous fluid, kidney, pancreas, ovary or vascular tissue. |
Medical practitioner AND Pathology service |
| Probable case |
Probable cases of iGAS are designated based on suggestive laboratory evidence AND clinical evidence. This means the isolation or detection of Streptococcus pyogenes by culture or nucleic acid testing from a normally non-sterile site. AND Clinical presentation consistent with severe, invasive disease such as: • streptococcal toxic shock syndrome • multi-organ failure • necrotising fasciitis • puerperal and/or neonatal sepsis |
Medical practitioner |
For further information on iGAS case definitions, refer to the Communicable Diseases Network Australia Surveillance Case .
Confirmed cases of iGAS are designated based only on definitive laboratory evidence so can be notified by medical practitioners and pathology services.
Probable cases of iGAS are designated based on suggestive laboratory AND clinical evidence. Therefore, notifications of probable cases are expected from medical practitioners who have access to both the relevant laboratory and clinical information.
