HPV infection and cervical disease: a review

Cervical cancer remains a significant problem worldwide particularly in underdeveloped countries. The disease and its financial impact are significant. Infection with the human papilloma virus (HPV) is necessary for the development of cervical cancer and its precursors. HPV also causes precancer and cancer elsewhere in the lower genital tract in women and men, as well as cancers of the aerodigestive tract. Whilst non-sexual transmission has been reported, the usual method of transmission is by sexual intercourse with the virus deposited on the basement membrane of the cervical epithelium. It is then taken up by the basal cells, and viral amplification occurs with the maturation of the squamous epithelium. During this process, it remains hidden from the host immune system, thus not mounting an immune response in many instances. About half of the women infected with HPV do not develop clinically detected serum antibody levels and are thus at risk of re-infection with the same HPV type. HPV vaccination produces sustained levels of serum-neutralising antibodies and has been shown to be effective in reducing disease caused by the vaccine-associated HPV types. Vaccination is considered well tolerated and safe with syncope and venous thromboembolism reported more frequently that would be expected. Vaccination will not protect against pre-existing HPV infection and hence may not provide complete protection in all women, and as the duration of protection is not known, for the time being routine Pap testing screening according to the Australian guidelines should continue.