Papillomaviruses

Both epidemiological and experimental evidence suggests sexual activity contributes to the etiology of cervical cancer. Searches for a responsible agent have pointed to an association with human papillomavirus (HPV). These viruses are nonenveloped, approx 55 nm in diameter, contain a double-stranded DNA genome of approx 8 kb, and are grouped with the Papovaviridae . To date 70 types are known, the subtypes with the early (E) genes E6 and E7 having the capacity for involvement with cellular transformation (1 ).