Symptoms+and+Diseases

= Symptoms and Diseases   =

Symptoms
As a herpesvirus, EBV infection is endemic in the human population, affecting most human adults. About 90-95% of the US adult human population contains EBV, if in a latent form. Because Epstein-Barr infects B lymphocytes and epithelial cells, its primary symptoms are swelling of the lymph nodes (lymphadenopathy) and swelling of the throat (pharyngitis), as well as fever. More rarely, EBV can cause swelling of the spleen or liver, or even problems with the heart or central nervous system. Symptoms usually persist for no more than 1 or 2 months.

[[image:epsteinbarrvirus/tumor_necrosis_factor.gif]]
//A possible signal pathway by which EBV causes cancerous growths of cells. Source: MicrobiologyBytes.//

Diseases
EBV is strongly linked with infectious mononucleosis. It is also a cofactor in Burkitt’s lymphoma (primarily in East Africa) and pharyngeal cancer (primarily in Southeast Asia and China). EBV infection of B lymphocytes can contribute to abnormal growth of these cells, causing lymphoma, while its infection of pharyngeal epithelial cell can likewise cause cancer in these cells.

Transmission
EBV spreads through saliva. When infected B cells and epithelial cells produce EBV, they release the virions into the saliva. (See the diagram on the Replication, Reproduction, and Infection page). Asymptomatic (i.e., healthy) carriers of EBV still shed the virus into their saliva and can still infect others. Direct contact is required for transmission (hence the nickname "kissing disease"). Despite the fact that transmission of EBV through the blood or the air is quite rare, the spread of the virus is still quite difficult to control

Diagnosis and Treatment
EBV is diagnosed through serologic tests. Because EBV contains proteins that trigger the production of lymphocytes in order to generate more hosts for itself, those infected with EBV will have an elevated lymphocyte count. A Paul-Bunnell test can also be used, as EBV causes the production of heterophile antibodies. While it is possible to detect EBV in the blood and tissues, this is unnecessarily for routine diagnosis and is only used for laboratory work. There are no vaccines or antivirals specific to EBV. Doctors can only prescribe drugs to manage the symptoms of EBV infection.

Epidemics
Most humans are infected with EBV, but do not display symptoms during most of their lifetimes. “Outbreaks” of EBV have been reported but never substantiated.