The best thing would be for you to talk with your own primary care doctor
, especially if you have any symptoms such as cough, sore throat
, or fever
, or if you are concerned that you may have been infected. They will be able to perform a complete physical examination and help you decide whether you have any evidence of an infection yourself. Based on what they find, they may just recommend rest and hydration, or they may recommend that you take antibiotics yourself.
As you probably know, laryngitis is an inflammation of the vocal cords. Most laryngitis is caused by viruses, also some cases are caused by bacteria. Both the viral causes and bacterial causes of laryngitis could be contagious, because both involve an infection of the upper respiratory tract that could be passed by coughing or in the respiratory secretions.
If the cause of the infection is bacterial, as it sounds like it is in your girlfriend's case, then it is most likely that she was prescribed antibiotics. If so, then the risk of contagion should be reduced after a couple days of taking the antibiotics regularly.
Again, contact your doctor at your earliest convenience, and good luck!