Invasive group A streptococcal disease (iGAS)

Invasive group A streptococcal disease (iGAS) is caused by infection with Group A Streptococcus bacteria (Group A Strep). These bacteria also cause common infections such as sore throat, scarlet fever and skin infections (for example, impetigo, school sores).

Sometimes these bacteria can enter other parts of the body such as the lungs, brain, blood or bones/joints causing serious and sometimes life-threatening illnesses.

In women who have given birth, infection inside the uterus (womb) can spread to the newborn or mother’s blood. This is called neonatal or maternal sepsis. These types of infections are called iGAS.

The bacteria can also cause other serious conditions such as necrotising fasciitis and toxic shock syndrome.

Symptoms

The symptoms of iGAS depend on where the infection is in the body.

Early symptoms can include:

• fevers, chills and/or sweats
• muscle or joint pain, or cold and mottled limbs in children
• localised muscle tenderness
• nausea and vomiting
• headache and/or neck stiffness
• redness of the skin or a wound site which spreads, becomes warm and painful, and may develop pus or ulceration
• lower abdominal pain, bleeding, or bad-smelling discharge from the vagina (in maternal sepsis).

How iGAS is spread

Group A Strep spreads through coughing, sneezing, kissing, or direct skin contact. Some people carry the bacteria in their throat or skin without getting sick and might spread it to others. However, people who have symptoms of Group A strep infection are far more likely to spread it to others.

Who is at risk of infection

Most people who come into contact with Group A Strep will not develop iGAS disease.

However, those who might be more likely to develop iGAS infection include:

• people who have had close contact with someone with iGAS infection in the last 30 days
• Infants and the elderly
• Aboriginal and Torres Strait Islander people
• people with chronic illnesses (for example, cancer, diabetes, or chronic lung, heart, liver, and kidney diseases)
• people taking medications that lower their immune system
• people with skin damage such as cuts, insect bites, burns or surgical procedures, or who have skin or soft tissue infections (for example, cellulitis)
• people who inject drugs
• people with high alcohol consumption
• people living in crowded houses, especially when it is difficult to keep up with good hygiene.

Treatment

iGAS infection requires early treatment with antibiotics. See a doctor as soon as you notice severe symptoms or mild symptoms that are getting worse. The exact treatment required depends on where the infection is in the body and how severe it is. Most people require admission to hospital and those with necrotising fasciitis may need surgery.

Prevention

Good hygiene is the best way to prevent spread and infection with Group A Strep bacteria.

Wash your hands regularly, especially after coughing and sneezing and before preparing, eating, or serving food. Wash, treat, and cover skin sores and wounds until healed.

Children with impetigo or school sores should not attend school or other group settings until the blisters have dried out. If a doctor recommends antibiotics for a sore throat or skin infection, stay at home until 24 hours after starting them.

If you have contact with someone with iGAS

If you live with someone or have spent a lot of time in close contact with a person who has had iGAS within the last 30 days, you need to be alert to the symptoms of iGAS.

If you develop any skin infections, a sore throat or symptoms of iGAS, you should see your doctor as soon as possible to be assessed – tell the doctor about your close contact.

Public health response

Pathology laboratories and doctors are required to notify iGAS cases to ACT Health.

Communicable Disease Control staff then contact the affected person to ask for information about their infection and their contacts. They also provide information to contacts about how to prevent and recognise infection.

Institutions such as residential aged care facilities, hospitals and childcare centres should contact the Communicable Disease Control section at ACT Health if they are aware of two or more iGAS cases in residents or attendees of their facility within a 3-month period.

More information

iGAS is a notifiable disease. For more information about iGAS, speak with your doctor or call the Health Protection Service, Communicable Disease Control Section during business hours on 02 5124 9213.