​​Invasive Group A Streptococcus

​​​​Important Changes in Group A Strep Reporting and Response
​

​Streptococcus pyogenes, also called Group A Streptococcus (GAS), is a bacterium commonly found in the human throat or on the skin. The most common GAS infection is acute pharyngitis ("Strep throat"), while the most serious GAS infections are those which are invasive and identified in normally sterile sites (blood, CSF, synovial fluid, etc.). GAS is particularly dangerous to older adults: it is estimated that around 14% of people aged 65 and older who have invasive GAS die from the infection.

Symptoms

Symptoms of invasive Group A Streptococcus (iGAS):Copy of Strep A Reporting and Response.png

  • Cellulitis
  • ​Necrotizing fasciitis
  • Toxic shock syndrome
  • Pneumonia
  • Endocarditis

Symptoms of non-invasive Group A Streptococcus:

  • Strep throat
  • Impetigo
  • Scarlet fever

What needs to be reported to the Health Department?

(Illinois Case Definition, updated 6/25/24)

Group A Streptococcus, identified by culture or by detection of Strep A by nucleic acid testing from a normally sterile site, such as blood, cerebrospinal fluid (CSF), pleural fluid, peritoneal fluid, pericardial fluid, surgical aspirate, bone, joint fluid, or internal body site (e.g., lymph node, brain) in an individual who:

  • Resides in a residential facility (e.g. long-term care facility including skilled nursing facility, assisted living, ICF/DD, SMHRF, SLF, etc.; correctional facility including prison, jail, or juvenile justice facility; university or residential school; homeless shelter; group home; or other residential facility).​
  • Is post-partum (defined as identification, during the postpartum period, of GAS in association with a clinical postpartum infection, e.g., endometritis, or from either a sterile site or a wound infection. The postpartum period of interest includes all inpatient days and the first 7 days after discharge.
  • Is postsurgical (defined as identification, during the hospital stay or the first 7 days after discharge, of GAS from a sterile site or a surgical wound in a postsurgical patient for whom the indication for surgery was not a preexisting GAS infection).
  • Was hospitalized at the time of onset of infection, i.e. infection was neither present on admission nor incubating at the time of admission. Identification (by culture or nucleic acid testing) was from sample taken on hospital day 4 or later and symptoms associated with iGAS were not present on admission. Reason for admission was unrelated to GAS infection, either invasive or non-invasive.

If GAS is identified from a sterile site and found to be linked to congregate or healthcare setting, isolates must be saved for at least 6 months, for emm typing and whole genome sequencing purposes. Should this be necessary, specimen submission process must be coordinated with the Health Department.

Outbreak considerations

CDC and IDPH reinforce the importance of preventing additional cases in high-risk settings. The identification of even one case of invasive GAS in LTCF and hospital settings should prompt immediate investigation along with the Health Department. In LTCFs, one single case of iGAS will also trigger the start of a 4-month period during which the facility will conduct monitoring of additional GAS cases.

CDC Decision Tool for Investigating GAS infections in LTCFs

Prevention Key Points

  • There is no vaccine to prevent GAS infections.

  • Ensuring compliance to hand hygiene protocols is key to limit disease spread.

  • Ensuring adequate wound care helps preventing and spreading infections.

  • GAS infections must be treated promptly; antibiotics may be used preventatively when appropriate.

Additional Resources

CDC: Clinical Considerations for Group A Streptococcus

CDC: Preventing Group A Strep Infections

IDPH: Group A Streptococcus (GAS) Infections

KCHD: ​​​​Important Changes in Group A Strep Reporting and Response Flyer​​