Human papilloma virus (HPV) affects the skin and moist membranes. HPV can cause problems such as verrucas, genital warts and abnormal cell changes in the cervix. Read more about HPV.
Human immunodeficiency virus (HIV) attacks the immune system. HIV infection can lead to AIDS; however, with early diagnosis and treatment, most people don't go on to develop AIDS. Read more about HIV and AIDS.
