Which virus is responsible for causing infectious mononucleosis?

Infectious mononucleosis, often referred to as "mono," is primarily caused by the Epstein-Barr Virus (EBV), which is a member of the herpes virus family. This virus is highly prevalent and is typically transmitted through saliva, which is why it is sometimes colloquially known as the "kissing disease."

Once infection occurs, EBV can lead to the proliferation of specific types of white blood cells, resulting in the characteristic symptoms of mono, such as fatigue, fever, sore throat, and swollen lymph nodes. The immune response to this virus is what causes the symptoms associated with the illness.

While other viruses can cause similar symptoms or conditions, they do not specifically cause infectious mononucleosis in the same way that Epstein-Barr Virus does. For instance, the influenza virus primarily leads to flu-like symptoms but does not cause the specific set of symptoms and laboratory findings typical of mono. Cytomegalovirus (CMV) can cause a mono-like illness but is less common, and Herpes Simplex Virus (HSV) is associated with cold sores or genital herpes rather than mononucleosis.

Thus, the identification of Epstein-Barr Virus as the causative agent of infectious mononucleosis is well-supported