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. On the skin and in secretions from the nose, throat, vagina, or perianal area.
Bacteria can contaminate improperly prepared or refrigerated food.
Milk and eggs are most frequently associated with foodborne outbreaks. Rapid strep tests can be performed with a throat swab. Therefore, when a patient suspected of GAS pharyngitis has a negative rapid strep test, a culture should be performed to confirm the negative finding. Because the rapid strep tests are very specific, a positive test does not require throat culture confirmation. Indications for culturing throats or lesions of patients, siblings, and other household contacts vary according to circumstances.