Group A Streptococcus is a bacterium often found in the throat and on the skin. People may carry group A streptococci in the throat or on the skin and have no symptoms of illness. Most GAS infections are relatively mild illnesses such as "strep throat," or impetigo. On rare occasions, these bacteria can cause other severe and even life-threatening diseases
Strep throat is an infection caused by group A streptococcus bacteria, and it's very common among kids and teens. The symptoms of “strep throat” include fever, stomach pain, and red, swollen tonsils. Strep throat may produce mild or severe symptoms.