<unk> s are parasitic organisms that depend on other organisms (called hosts) for their survival, and cause cancer in such hosts. Three species of flukes (trematodes) are medically-proven<unk> s, namely the urinary blood fluke (Schistosoma haematobium), the Southeast Asian liver fluke (Opisthorchis viverrini) and the Chinese liver fluke (Clonorchis sinensis). S. haematobium is prevalent in Africa and the Middle East, and is the leading cause of bladder cancer (only next to tobacco smoking). O. viverrini and C. sinensis are both found in eastern and southeastern Asia, and are responsible for cholangiocarcinoma (cancer of the bile ducts). The International Agency for Research on Cancer declared them in 2009 as a Group 1 biological carcinogens in humans. Other parasites are also linked to various cancers. Among protozoan parasites, Toxoplasma gondii, Cryptosporidium parvum, Trichomonas vaginalis and Theileria are associated with specific cancer cells. Plasmodium falciparum can also be an indirect cause of cancer. Tapeworms such as Echinococcus granulosus and Taenia solium may directly or indirectly cause cancer. Liver flukes such as Opisthorchis viverrini and Platynosomum fastosum can cause cancer in domesticated animals. Roundworms such as Strongyloides stercoralis, Heterakis gallinarum, and Trichuris muris are known to cause cancer in animals.
Carcinogenic parasite
Food contaminant
Carcinogenic bacteria
Pathogenic fungus
Behavior-altering parasite
Opportunistic infection
Soil-transmitted helminthiasis
Co-carcinogen