Epstein Barr Virus (EBV)

The Epstein-Barr virus (HHV 4) is the pathogen in infectious mononucleosis and is also implicated in lymphomas (including Burkitt lymphomy) and nasopharyngeal carcinomas.

EBV enters the body through the mucosa. It replicates in epithelial cells of the oropharynx or cervix and enter B lymphocytes, where it continues to replicate. This results in the clinical picture of mononucleosis (kissing disease or Pfeiffer disease), which is characterized by fever and a generalized but mainly cervical swelling of the lymph nodes, typically accompanied by tonsillitis, pharyngitis, and some cases of mild hepatic involvement. EBV infects only a narrow spectrum of hosts and replicates very slowly. It persists in a latent state in B lymphocytes and can lead to their immortalization and tumor transformation.

EBV is excreted in saliva and pharyngeal secretions and is transmitted by close contact ("kissing disease"). As with all herpesviruses the level of generalized contamination is high (80-90 % of the adult population is infected), with the process beginning in childhood and continuing throughout adolescence. In undeveloped countries the frequency of occurrence is - because of the hygienic situation - much higher and amounts with the under-3 years old children close to 100%. The majority of infections run an asymptomatic course.