Invasive Group A Streptococcal Infection (IGAS): Update as of December 8, 2022, and Surveillance System

Update following several pediatric cases of invasive Group A Streptococcus infections, primarily among children under the age of 10 in several regions of France.

During the second half of November 2022, clinicians and pediatric intensive care specialists reported to Santé publique France and the Regional Health Agencies (ARS) a higher-than-usual number of pediatric cases of invasive Group A Streptococcus (IGAS) infections in their departments, some of which were fatal. These reports came from various regions (Occitanie, Auvergne-Rhône-Alpes, Nouvelle-Aquitaine) and primarily involved children under the age of 10.

To objectively assess an increase in cases toward the end of 2022, an initial analysis was conducted using nationally available data on Group A Streptococcus infections.

Key Points

  • Increase in non-invasive Group A Streptococcus (GAS) infections, particularly scarlet fever, since September 2022. The levels observed are close to those seen before the COVID-19 pandemic.

  • Increase in invasive GAS infections in France in 2022, particularly marked since November among children, with levels exceeding those of 2019.

  • These observations come against a backdrop where, during 2020 and 2021—likely due to the preventive measures implemented for COVID-19—the incidence of GAS infections was particularly low.

  • The current epidemiological situation regarding invasive Group A Streptococcus infections is not linked to the emergence of a new bacterial strain but is primarily associated with two already known genotypes (emm12 and emm1).

Invasive Group A Streptococcus Infections in France

Group A streptococcus (GAS) is a strictly human pathogen transmitted via respiratory droplets and direct contact (nasal secretions, skin lesions, etc.). It most commonly causes mild, non-invasive infections, such as strep throat, impetigo, and scarlet fever. More rarely, it causes serious invasive infections (necrotizing skin infections, puerperal infections, pneumonia and pleuropneumonia, and meningitis) that may be associated with streptococcal toxic shock syndrome (STSS).

To limit the risk of transmission, it is recommended to follow the same preventive measures used against winter viruses:

  • handwashing,

  • wearing a mask for people with respiratory infections,

  • coughing or sneezing into the crook of the elbow.

Implementation of enhanced surveillance

Active surveillance is being implemented by Santé publique France and the GFRUP (Francophone Group for Pediatric Intensive Care and Emergency Medicine) to supplement the existing surveillance system, better assess the epidemiological situation, and characterize severe cases admitted to intensive care. The protocol for this surveillance is available on our website.

This data collection complements the microbiological surveillance of Group A streptococci conducted by the National Reference Center for Streptococci, as well as that of the EPIBAC network. The GAS strains submitted to the NRC by bacteriology laboratories are characterized there, particularly at the genotypic level.

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