what causes only sore throat
A bacterial infection can also cause a sore throat. These types of infections include: 1  strep throat: inflammation of the throat caused by the Streptococcal bacteria. 2  diphtheria: infectious disease that causes throat inflammation.
Because strep throat is a common cause of sore throats, your doctor may swab the back of your throat and examine the sample for the Streptococcal bacteria. He or she may also run a blood test to determine whether you have a viral or bacterial infection.