Infectious causes of Cancer: Bacteria, Virus and Parasites

Infectious agents, such as viruses and bacteria, are the causes of several common cancers. Infection with the bacterium Helicobacter pylori predisposes to gastric cancer. Chronic infection with HBV, HCV predisposes to hepatocellular carcinoma.  In this blog post you can find list of bacterial, viral and parasitic agents who have found to cause or predispose individuals to various types of cancer.

List of viruses that causes cancer

  1. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are associated with liver cancer (Hepatocellular carcinoma)
  2. Epstein-Barr virus (EBV) is associated with lymphoma and nasopharyngeal cancer.  EBV is the primary cause of infectious mononucleosis but EBV is also a causative agent in many aggressive neoplasms, including 20% of cases of Hodgkin’s lymphoma (one of the most common lymphomas of adolescence), nasopharyngeal carcinoma, and a subtype of Burkitt’s lymphoma.
  3. Human papillomavirus (HPV) is a major cause of cervical, anal, penile, and oropharyngeal cancer.  The most common clinically significant manifestation of persistent genital HPV infection is cervical intraepithelial neoplasia (CIN). HPV-16 and HPV-18 is implicated as the cause nearly 70% Carcinoma of the cervix
  4. Human herpesvirus 8 (HHV-8) is the causative agent of Kaposi’s sarcoma.
  5. Human immunodeficiency virus (HIV): HIV does not causes  cancer directly but HIV infection increases a person’s risk of getting several types of cancer such as Kaposi sarcoma, invasive cervical cancer, non-Hodgkin lymphoma and central nervous system lymphoma etc.
  6. Human T-lymphotrophic virus-1 (HTLV-1): HTLV-1 has been linked with a type of lymphocytic leukemia and non-Hodgkin lymphoma called adult T-cell leukemia/lymphoma (ATL).

List of Bacterial/Parasitic agents linked with cancers

  1. Chronic infection with Helicobacter pylori predisposes to stomach cancer and to gut mucosa-associated lymphoid tissue (MALT) lymphoma.
  2. Schistosoma haematobium, a parasitic flatworm is associated with high incidence of  bladder cancer
  3. Opisthorchis viverrini and Clonorchis sinensis are liver flukes (a type of flatworm) that have been linked to increased risk of developing cancer of the bile ducts