section_path: Causes/Infection
section_name: Infection
paragraph_text: Infection
  
  Worldwide, approximately 18% of cancer deaths are related to infectious diseases. This proportion ranges from a high of 25% in Africa to less than 10% in the developed world. Viruses are the usual infectious agents that cause cancer but bacteria and parasites may also play a role. Oncoviruses (viruses that can cause human cancer) include:
  
  Bacterial infection may also increase the risk of cancer, as seen in
  
  Parasitic infections associated with cancer include: