Group A streptococcal infection risk factors

Overview
The group A streptococcus bacterium (Streptococcus pyogenes, or GAS) is a form of Streptococcus bacteria responsible for most cases of streptococcal illness. Other types (B, C, D, and G) may also cause infection.

Risk Factors
Invasive disease: elderly, immunosuppressed, persons with chronic cardiac or respiratory disease, diabetes, skin lesions (i.e. children with varicella chicken pox, intravenous drug users) African-Americans, American Indians.

Noninvasive disease: children (especially elementary school age) at highest risk.

Transmission
Person to person by contact with infectious secretions. Asymptomatic pharyngeal carriage occurs among all age groups but is most common among children.