ReviewRisk factors for and prevention of human papillomaviruses (HPV), genital warts and cervical cancer
Section snippets
HPV infection
Papillomaviruses are double-stranded deoxyribonucleic acid (DNA) viruses that are small, non-enveloped and icosahedral with a diameter of 52–55 nm.1, 2 They are also epitheliotropic, which means that they generate productive infections merely within the stratified epithelia of the skin, oral cavity and anogenital tract. Infection of basal epithelial cells initiates the viral life cycle, which is linked to differentiation of the infected epithelial cells.3
Of more than 100 HPV types that have
Genital warts
Approximately 90% of genital warts – also known as condylomata acuminate – are caused by infection with HPV-6 and HPV-11.30, 37, 38, 39, 40 Genital warts are highly contagious with the majority of warts developing within 2–3 months of infection.21, 41 Winer et al.21 found the median duration between incident infection with HPV-6 or HPV-11 and development of genital warts to be 2.9 months among 18–20 year old females in the U.S. Furthermore, among females newly infected with HPV-6 and HPV-11,
Cervical cancer
For cervical cancer to develop, the following occur: infection with HPV; persistence of HPV infections; development of precancerous lesions in cervical cells that have been persistently infected with HPV; and invasion of cervical cells (cancer). It is common for HPV infections to clear, but less frequent for precancerous lesions to regress to normal cells.53
Cervical cancer ranks as the second most common cancer among both women of all ages and those aged 15–44 years worldwide. It was estimated
HPV vaccines
There are two vaccines currently available to prevent infection with HPV types responsible for most cervical cancer cases. The aim of prophylactic vaccination is to reduce incidence of anogenital cancers and precancerous lesions, with additional protective benefits against genital warts for those receiving the quadrivalent vaccine.69
In June 2006, the U.S. Food and Drug Administration (FDA) approved the prophylactic quadrivalent vaccine, Gardasil® (Merck, New Jersey, United States), for females
Summary
HPV has been associated with the development of cervical cancer in females, genital warts, and other anogenital cancers. It has also been linked to oropharyngeal, oral and laryngeal squamous cell carcinomas, and non-melanoma skin cancer. Although genital warts do not result in high morbidity and mortality, they are associated with significant medical costs and psychological distress to sufferers due to anxiety, discomfort, pain and embarrassment. The major risk factors for HPV infection are
Conflict of interest
The authors have no conflicts of interest.
References (109)
- et al.
Structures of bovine and human papillomaviruses. Analysis by cryoelectron microscopy and three-dimensional image reconstruction
Biophys J
(1991) - et al.
Chapter 1: HPV in the etiology of human cancer
Vaccine
(2006) Immune responses to human papillomavirus
Vaccine
(2006)- et al.
Worldwide distribution of human papillomavirus types in cytologically normal women in the International Agency for Research on Cancer HPV prevalence surveys: a pooled analysis
Lancet
(2005) - et al.
Worldwide prevalence and genotype distribution of cervical human papillomavirus DNA in women with normal cytology: a meta-analysis
Lancet Infect Dis
(2007) - et al.
Chapter 4: burden and management of non-cancerous HPV-related conditions: HPV-6/11 disease
Vaccine
(2006) - et al.
Sexual behaviour in Britain: reported sexually transmitted infections and prevalent genital Chlamydia trachomatis infection
Lancet
(2001) - et al.
Sex in Australia: sexually transmissible infection and blood-borne virus history in a representative sample of adults
Aust N Z J Public Health
(2003) - et al.
Human papillomavirus and cervical cancer
Lancet
(2007) - et al.
Case-control study of the husbands of women with dysplasia or carcinoma of the cervix uteri
Lancet
(1981)