Persistent infection of the cervix with high-risk types of human papillomavirus (HPV)
has been established as a necessary (but not sufficient) cause for the development
of cervical cancer [1]. Evidence suggests that HPV infection precedes the
development of cervical cancer by several decades and that persistent infection with
HPV is necessary for the development and progression of pre-cancerous lesions of
the cervix, either to higher grades of pre-cancerous disease or to invasive cancer – a
process that can take 10–30 years [2].