This virus produces infectious mononucleosis in young adults throughout the world and seems to contribute to Burkitt's lymphoma and nasopharyngeal carcinoma. The infection in childhood is common and asymptomatic but it may rarely cause mononucleosis syndrome. In young adults the infection is very common and symptomatic. The difference is attributed to the exposure to a large quantity of viruses by deep kissing. It is found in lymphoid tissues and in the epithelium of the nasopharynx and probably of the cervix.
B lymphocytes acquire the virus mainly from the pharynx.
After infection, the lymphocyte under the influence of the viral genome produce new antigens which are deposited on their surface. T lymphocytes react to these antigens, become blastoid and form the atypical lymphocytes of the peripheral blood seen in these patients who at this piont develop the full symptoms of infectious mononucleosis which, evidently, is immunopathologically mediated. Some individuals cannot mount this t-lymphocytic reaction will succumb to the primary EVB infection. This is the case of those suffering of X-linked lymphoprolipherative disorder, Duncan's syndrome. Pathology Mononucleosis hepatitis is characterized by peculiar necroinflammatory changes which, at the difference of classical viral hepatitides consist of more inflammation and less necrosis.