Strep throat is an upper respiratory tract infection that affects school-aged children between 5 and 15 years-old. In the United States, children typically get the disease once every 4 years, making it one of the most commonly-occurring illnesses within that age group.
The infection is caused by the Streptococcus bacteria of the Group A type, which is why the disease is medically known as Streptococcal pharyngitis. It is transmitted from person-to-person by direct contact with fluids coming from the mouth. Strep throat is very contagious and can also be transferred between individuals sharing eating utensils and cups.
Strep Throat is most-common during late autumn, winter, and early spring, when children are huddled closely indoors, making transmission easier. When children are huddled close to one another at school or in daycare centers during the cold months, transmission of the disease becomes inevitable.
Strep throat symptoms appear almost suddenly, usually incubating between 1-5 days after a person is exposed to the bacteria. It presents quite differently from other cases of throat infections, which is why the diagnosis of Streptococcal pharyngitis is relatively easier and often based on its symptoms. Once the doctors deem the case a strep throat infection, a throat culture for Streptococcus bacteria is ordered to confirm their diagnosis.
The following are the signs and symptoms of a strep throat infection.
1. Pus on the Tonsils

Source: https://www.aboutkidshealth.ca/