HPV18

HPV18 is one of the high-risk types of human papillomavirus, a small circular double-stranded DNA virus in the Alphapapillomavirus genus. Its genome is about 8,000 base pairs in length. HPV18 is among the principal causes of cervical cancer and, along with HPV16, is routinely assessed in high-risk HPV testing and genotyping. Infection with HPV18 is associated with an elevated risk of developing high-grade cervical intraepithelial neoplasia (CIN) and invasive cancer.

The oncogenic potential of HPV18 is largely driven by the viral E6 and E7 oncoproteins, which can disrupt cellular tumor suppressor pathways. Most HPV18 infections are asymptomatic and are cleared by the immune system within one to two years. However, persistent infection increases the likelihood of progression to CIN and cancer if unchecked. Beyond the cervix, HPV18 is linked to other anogenital cancers (such as vulvar, vaginal, and anal cancers) and a subset of oropharyngeal cancers.

Transmission occurs mainly through sexual contact; non-sexual transmission is rare. Prevention relies on vaccination and screening. Vaccines such as Gardasil 9, which covers nine HPV types including HPV18, and Cervarix, which targets HPV16 and HPV18, provide strong protection against HPV18 infection. Vaccination is recommended for preteens and is also offered to older individuals in some guidelines. Regular cervical cancer screening, using cytology and HPV testing, helps detect precancerous changes and reduces disease burden when combined with vaccination.