Human Papillomavirus (HPV) / Genital Warts

Human Papillomavirus (HPV) is a very common sexually transmitted virus, with more than 100 identified strains. Most people who are sexually active will acquire at least one HPV infection in their lifetime. Low-risk strains (such as types 6 and 11) cause genital warts, while high-risk strains (particularly types 16 and 18) are responsible for the majority of cervical cancers and contribute to cancers of the vulva, vagina, penis, anus, and oropharynx. Most infections are cleared naturally by the immune system within one to two years without ever causing symptoms, but persistent infection with a high-risk strain is the single most important risk factor for cervical cancer. Cervical cancer remains one of the leading cancers among Nigerian women, largely because organised screening and HPV vaccination coverage remain low, making awareness, vaccination, and regular screening critically important.

Most HPV infections cause no symptoms at all and are only detected through screening. When genital warts develop: • Small, flesh-coloured, pink, or grey growths in the genital or anal area, which may be flat or raised, single or clustered in a cauliflower-like pattern • Itching, mild discomfort, or bleeding in the affected area • Warts can appear weeks to months after exposure, or not at all When high-risk strains cause cellular changes: • No symptoms in early stages; abnormal cells are typically detected only through a Pap smear or HPV test • Advanced cervical cancer may eventually cause abnormal vaginal bleeding, bleeding after sex, or unusual discharge, but by this stage the disease is already advanced, which is why regular screening rather than waiting for symptoms is essential

HPV spreads through direct skin-to-skin contact during vaginal, anal, or oral sex with an infected person. Transmission can occur even when the infected partner has no visible warts or symptoms, and condoms reduce but do not eliminate risk since they do not cover all exposed skin. The virus infects the basal layer of skin or mucous membrane cells; in most people the immune system clears the infection, but in some it persists, and with high-risk strains, persistent infection can gradually cause abnormal cell changes that may progress to cancer over 10-20 years if undetected and untreated.

• Multiple sexual partners, or a partner who has had multiple partners • Early age at first sexual activity • Not having received the HPV vaccine • Weakened immune system, including HIV infection, which impairs the body's ability to clear the virus • Smoking, which increases the risk that a high-risk HPV infection will progress to cervical cancer • Long-term use of combined oral contraceptives (a modest, well-studied association with cervical cancer risk)

• Genital and anal warts, which can recur even after treatment • Cervical cancer, the most significant long-term complication of high-risk strain infection • Cancer of the vulva, vagina, penis, anus, or oropharynx (throat), though these are less common than cervical cancer • Recurrent respiratory papillomatosis in infants born to mothers with active genital warts, a rare complication from transmission during vaginal delivery

HPV-related disease is one of the most preventable cancers through a combination of vaccination and screening: • HPV vaccination is most effective when given before the start of sexual activity (ideally ages 9-14), but still provides benefit for sexually active young adults up to age 26 and, in some guidelines, beyond • Consistent condom use reduces, though does not eliminate, transmission risk • Routine cervical cancer screening (Pap smear or HPV DNA testing) detects pre-cancerous changes years before they could develop into cancer, allowing simple, effective treatment • Limiting number of sexual partners and avoiding smoking both reduce risk