According to Mayo Clinic, strep throat is contagious. The bacteria that cause strep throat are known as streptococcal bacteria. Strep throat may be spread through coming into contact with airborne droplets from an infected person's choking or sneezing or through sharing beverages or food with that person.
According to WebMD, people with strep throat are contagious for as long as they exhibit symptoms. When infected people take antibiotics, they are usually no longer contagious within 24 hours. However, without antibiotics, someone may be contagious for up to 3 weeks. The most common symptoms of strep throat include a severe sore throat, painful swallowing, fever in excess of 101 degrees Fahrenheit, swollen tonsils or lymph nodes, and white or yellow spotting at the back of a bright red throat.
Strep throat is caused by the group A streptococcus bacteria, according to Kids Health. Because an untreated strep throat infection can lead to complications that affect other parts of the body, it is most widely treated using antibiotics. To ensure that the infection has been treated, individuals must take a full course of antibiotics even if they begin feeling better in a day or two.