Strep throat pathophysiology

Transmission
The illness is caused by the bacterium Streptococcus pyogenes and is spread by direct, close contact with an infected person via respiratory droplets (cough or sneezing). Casual contact rarely results in transmission. Rarely, contaminated food, especially milk and milk products, can result in outbreaks. Untreated patients are most infectious for 2-3 weeks after onset of infection. The incubation period, the period after exposure and before symptoms show up, is difficult to establish as some people don't become symptomatic. However, it is thought to be between two and five days. Strep is caused by bacteria of a type called group A beta-hemolytic streptococci. Symptoms include sore throat, fever, headache, and in some cases, chills, nausea, and vomiting. The patient usually experiences swelling of the tonsils and lymph nodes in the neck.