In addition to what JGF25 said Group B strep is a type of strep called Streptococcus agalactiae. It also can cause a sore throat and other infections but is most commonly worried about because of its problems in child birth. If you are positive they will treat you during delivery or just before having the baby because of the risk of infecting the baby if you have the bacteria. So they will check a few times to see if you carry the bacteria. If you do they will treat you with antibiotics. There is also a vaccine you can get in adolescent years before pregnancy.
mkh9
If you have Group B Strep and you are pregnant, the doctor needs to know. Babies can become very sick from a Group B strep infection but this is not 100% i.e., not every baby born to a Group B strep infected mother gets sick. Are you pregnant? Group B strep is treated with penicillin or the like.