what causes strep throat

Strep throat is an infection in the throat and tonsils caused by bacteria called group A Streptococcus (group A strep) . The bacteria that cause strep throat are easily spread by the oral and nasal secretions and droplets of an infected person. These droplets can be released into the air when an infected person coughs, sneezes, talks, laughs, or sings. The bacteria can live in traces of an infected person’s saliva or nasal discharge. Strep throat is most common in children, but it affects people of all ages. Symptoms of strep throat can include throat pain, painful swallowing, fever, swollen lymph glands, and white patches or streaks of pus on the tonsils. If left untreated, strep throat can cause complications such as kidney inflammation or rheumatic fever.