Infectious mononucleosis is caused by which virus?

Infectious mononucleosis is primarily caused by the Epstein-Barr virus (EBV), which is a member of the herpesvirus family. EBV is commonly known for its role in causing mono, especially in adolescents and young adults. The virus is transmitted through saliva, earning the nickname "the kissing disease," and can lead to symptoms such as fatigue, fever, sore throat, swollen lymph nodes, and an enlarged spleen.

Understanding the nature of EBV is crucial; it is one of the most prevalent viruses globally, and most people will be infected with it at some point in their lives, often during childhood. While the virus usually remains dormant after the initial infection, it can reactivate and sometimes lead to complications.

The other viruses listed do not cause infectious mononucleosis. Human Immunodeficiency Virus (HIV) is known for attacking the immune system and leading to AIDS. Herpes Simplex Virus is primarily associated with oral or genital herpes, not mononucleosis. Cytomegalovirus can cause similar symptoms but is less commonly the cause of the classic presentation of infectious mononucleosis. Understanding these distinctions is essential for recognizing the clinical presentation and appropriate management of mononucleosis.