Anyone can get streptococcal infections. Host susceptibility can affect the severity of infection in individuals. The same type of bacteria can cause severe infection in one person and mild or asymptomatic disease in others. GAS pharyngitis and skin infections are more common in school-aged children than in adults except during epidemics. Close contact with carriers such as occurs in schools, child care, and military institutions.
Transmission can occur by indirect contact with objects or food.
The second most common site of GAS infection is the skin. The incubation period of GAS pharyngitis is 2-5 days. Skin infections may develop 7-10 days after exposure. In general, patients treated with penicillin will not be able to transmit GAS 24-48 hours after beginning treatment. Patients with uncomplicated GAS pharyngitis, who are not treated with antibiotics, can transmit the bacteria for weeks or months.