Which virus is known to cause infectious mononucleosis?

The Epstein-Barr Virus (EBV) is well-known as the primary causative agent of infectious mononucleosis, commonly referred to as "mono." This disease is characterized by symptoms such as fever, sore throat, swollen lymph nodes, and fatigue. EBV is a member of the herpesvirus family and is one of the most widely distributed viruses in humans.

Infectious mononucleosis is often associated with the proliferation of atypical lymphocytes, which can be observed through specific laboratory tests such as the heterophile antibody test. The virus typically spreads through saliva, earning it the nickname "the kissing disease."

In contrast, while the other viruses listed can cause a range of diseases, they are not associated with infectious mononucleosis. Hepatitis B virus primarily affects the liver and is not known for causing the symptoms associated with mono. Yellow fever virus is transmitted by mosquitoes and causes a serious hemorrhagic disease. Adenovirus is associated with respiratory illnesses and other infections but does not cause infectious mononucleosis. Therefore, the identification of Epstein-Barr Virus as the cause highlights its significant role in this specific infectious disease.