See also

Sepsis
Cellulitis and other bacterial infections
Parapneumonic effusion
Sore Throat
Bone and joint infection

Key Points

1. Invasive Group A Streptococcal disease (iGAS) is associated with significant morbidity and mortality
2. There is an increased risk of secondary cases of iGAS in household contacts of an index case
3. Inform household contacts about the clinical features of iGAS and provide chemoprophylaxis as soon as possible

Background

• Group A Streptococcus (GAS), also known as Streptococcus pyogenes, commonly colonises the skin, nasopharynx or anogenital tract of children
• GAS causes a wide range of clinical disease in children, from mild illnesses such as pharyngitis and impetigo, to severe, life-threatening invasive infections 

Invasive GAS disease (iGAS)

iGAS is defined by the isolation of GAS from a normally sterile site. Manifestations include: 

• bacteraemia/septicaemia
• streptococcal toxic shock syndrome (STSS)
• necrotising fasciitis
• pneumonia and empyema
• retropharyngeal abscess
• osteomyelitis or septic arthritis
• meningitis

Cellulitis, scarlet fever and pharyngitis are not considered to be invasive disease

Household contacts of a case of iGAS

• Definition: those who have spent more than 24 hours in the same house as an index case in the 7 days prior to symptom onset until 24 hours after effective antibiotic therapy commenced
• Household contacts are at increased risk of iGAS compared with the general population
• Secondary cases usually occur within a month of the index case, but predominantly in the first 7 days

Management

• Some experts and guidelines recommend antibiotic chemoprophylaxis to reduce the risk of iGAS in household contacts, although this has not been studied extensively
• Regardless of whether chemoprophylaxis is prescribed, all household contacts should be educated about their increased risk of iGAS and the early signs and symptoms of iGAS that require prompt medical evaluation. These include:
  • fever
  • severe muscle aches
  • sore throat
  • cellulitis
  • diarrhoea or vomiting
  • severe headache
• Throat swabs to assess GAS carriage in asymptomatic close contacts are not helpful
• Asymptomatic household contacts are not required to isolate or restrict activities

Consider consultation with local paediatric (or infectious diseases specialist) team when

Non-household close contacts or concerns regarding compliance with chemoprophylaxis

Parent information

Invasive Group A Streptococcal Disease

Last updated May 2023