Invasive Group A Streptococcal Infections in 10 US States

Area of Science:

• Infectious Diseases
• Epidemiology
• Public Health Surveillance

Background:

• Invasive group A Streptococcus (GAS) infections pose a significant public health threat, causing considerable morbidity, mortality, and economic burden.
• Understanding current trends in invasive GAS disease is crucial for effective public health interventions.

Purpose of the Study:

• To update the incidence rates of invasive GAS disease across 10 US states.
• To analyze trends from 2013 to 2022, identifying demographic and risk factor associations.

Main Methods:

• Population-based surveillance data from the Active Bacterial Core surveillance network (34.9 million persons) were analyzed.
• Cases were defined by GAS isolation from sterile sites or specific clinical syndromes (2013-2022).
• Whole-genome sequencing was employed from 2015 onwards for isolate characterization and antimicrobial susceptibility testing.

Main Results:

• A substantial increase in invasive GAS incidence was observed, rising from 3.6 to 8.2 per 100,000 persons (2013-2022).
• The highest incidence was in individuals aged 65+, but the greatest relative increase occurred in adults aged 18-64.
• Elevated incidence rates were noted in American Indian/Alaska Native populations, those experiencing homelessness, people who inject drugs, and long-term care facility residents. Antimicrobial resistance to macrolides and clindamycin increased significantly.

Conclusions:

• Invasive GAS infections have markedly increased in the US between 2013 and 2022.
• Targeted prevention and control strategies are urgently needed, focusing on populations disproportionately affected by invasive GAS.