Qiyasi ya sanya haɗarin kamuwa da cutar kansa a duniya da kashi 16.1%. Cututtukan ƙwayoyin cuta sune abubuwan haɗari ga kansar mahaifa, 80% na cututtukan hanta, da 15-20% na sauran cututtukan daji. Wannan rabo ya bambanta a yankuna daban-daban na duniya daga babban na 32.7% a yankin Saharar Afirka zuwa 3.3% a Australia da New Zealand. Helicobacter pylori yana da alaƙa da ciwon daji na ciki, kuma Mycobacterium, wasu ƙwayoyin cuta da ƙwayoyin cuta suma suna da tasiri. Kwayar cutar da ke iya haifar da ciwon daji ana kiranta oncovirus ko ƙwayar cuta. Wadannan sun hada da kwayar cutar papilloma na mutum, wanda ke hade da ciwon daji na mahaifa da kuma nasopharyngeal carcinoma ; Kwayar cutar Epstein-Barr, wanda ke hade da nau'in kwayar cutar Epstein-Barr da ke hade da lymphomas na lymphoproliferative ; Kaposi's sarcoma herpesvirus, wanda ke hade da sarcoma na Kaposi da lymphoma na farko ; ciwon hanta na B da hepatitis C wadanda ke hade da ciwon hanta; mutum T-cell cutar sankarar bargo-1, wanda ke hade da manya T-cell cutar sankarar bargo / lymphoma ; da kuma cutar sankarar bargo, wanda ke hade da ciwon nono