Chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus infection (CAEBV) is a very rare complication of an Epstein Barr virus (EBV). Most people (about 95% by adulthood) become infected by EBV at some point of their lives and never have any health problems. Some people with EBV will develop infectious mononucleosis or other illnesses, and will recover from their illness with no other problems. Very rarely, an EBV infection will develop into CAEBV. Signs and symptoms of CAEBV may include fever, swollen lymph nodes, enlarged liver and/or spleen, liver function test abnormalities, and low levels of certain types of blood cells. Some people develop anemia, over sensitivity to mosquito bites, rash, oral ulcers, nerve damage, liver failure, and/or interstitial pneumonia. These symptoms may occur irregularly or continuously, and tend to get worse over time.

CAEBV occurs when people with an EBV infection are unable to control the infection and the virus remains "active," allowing symptoms of EBV infection to persist and progress. It is not known why some people develop CAEBV and others do not. Because this condition is so rare, it is not clear how many people with an EBV infection will go on to develop CAEBV.

CAEBV is diagnosed based on the signs and symptoms and the results of blood tests that show EBV DNA at high levels, indicating an active infection. It is a common misconception that people with fatigue alone (and not the symptoms mentioned above) and positive blood markers for EBV have CAEBV. These blood markers are present for life in people with prior EBV exposure, and are not markers of an active infection of CAEBV.

Over time, CAEBV can lead to progressive failure of the immune system which, if not treated, can lead to potentially fatal complications such as a blood cell disorder known as hemophagocytic syndrome, multiorgan failure, or EBV-positive lymphoma. The only well-documented, effective treatment for CAEBV is hematopoietic stem cell transplantation.