Epstein-Barr virus spreads through contact with an infected person's saliva, blood or semen, explains WebMD. Activities that can transmit the virus include kissing, sex, drinking from the same glass as an infected person and using the toothbrush of an infected person. Blood transfusions and organ transplants can also transmit it.
Someone with Epstein-Barr virus can become ill with mononucleosis. A person with the virus does not have to be ill to transmit it to someone else, notes WebMD. Many people who carry the virus do not become ill. When symptoms occur, they are often mild and can resemble a cold or flu. Symptoms include fever, sore throat, lack of appetite, swollen neck glands and fatigue.
Symptoms can take four to six weeks after transmission to appear, states WebMD. They can take two to four weeks to resolve, although fatigue may persist for a couple of months. Doctors look for certain signs in diagnosing mononucleosis, including a swollen liver, enlarged spleen and white patches on tonsils. Blood tests aid in diagnosis by detecting antibodies and white blood cells that fight the Epstein-Barr virus.
The Epstein-Barr virus can lead to diseases besides mononucleosis, according to WebMD. These include diarrhea and ear infections in children, some types of cancer and Guillain-Barre syndrome. The virus is also associated with multiple sclerosis, but further research needs to determine whether it can lead to multiple sclerosis.