ABSTRACT
Several infectious agents are established causes of non-Hodgkin’s lymphoma in humans. They include human immunodeficiency virus (HIV), Epstein–Barr virus, human herpes virus 8, hepatitis C virus (HCV), and Helicobacter pylori. HIV-associated non-Hodgkin’s lymphomas, although histologically heterogeneous, are characterized by an aggressive clinical course. High-grade disease is common and extranodal sites are often involved, with lesions in the central nervous system being virtually unknown except in the immunosuppressed. Serological surveys from many different populations consistently reported that more than 90% adults are positive for Epstein–Barr virus infection. HCV is hepatotropic and causes hepatitis, liver cirrhosis, and hepatocellular carcinoma. Lyme borreliosis is a multiorgan infection caused by tick-borne spirochetes of the Borrelia burgdorferi. Campylobacter jejuni is probably the most prevalent cause of bacteria-mediated diarrheal disease worldwide and is considered an initiating factor in chronic autoimmune diseases, such as the Guillain–Barre syndrome and reactive arthritis.
