Mononucleosis (or "mono") is an infectious disease caused by the Epstein-Barr virus (EBV). EBV is a member of the Herpes Virus family.
An infectious disease doctor specializes in diseases caused by infectious agents such as bacteria, viruses, fungi, and parasites. They are responsible for diagnosing, treating, and preventing infections, including conditions like tuberculosis, HIV/AIDS, malaria, and hospital-acquired infections. They use laboratory tests, cultures, and other diagnostic methods to identify infectious agents and determine the most effective treatments. It is advisable to see an infectious disease specialist if you experience persistent symptoms of infection, fever of unknown origin, recurrent infections, or complex infectious diseases.
Remember that for the proper selection of health professional that treats mononucleosis you must consider the nature, severity and symptoms you are presenting.