Final answer:
The probable diagnosis for the student's symptoms is Mononucleosis. Mononucleosis is typically caused by the Epstein-Barr Virus (EBV) and manifests with symptoms such as malaise, sore throat, general lethargy, enlarged lymph nodes and spleen.
Step-by-step explanation:
The probable diagnosis for the 19-year-old student's symptoms is Mononucleosis. Mononucleosis, also known as the kissing disease, is typically caused by the Epstein-Barr Virus (EBV). The symptoms mentioned, such as malaise, sore throat, general lethargy, enlarged lymph nodes and spleen, atypical lymphocytes in the CBC, and a positive blood work for Epstein-Barr viruses, are consistent with a diagnosis of mononucleosis.