As a DNA virus, HPV has a simple structure. It consists only of a protein capsid, the outer shell, and an encapsulated core. HPV is classified as high-risk or low-risk according to its pathogenicity, and the classification is marked by its ability to cause cancer. 15 high-risk HPV types, alone, cause high levels of cervical intraepithelial neoplasia and cervical cancer.
Humans are the only hosts for HPV, and it likes to settle in warm, moist places in the body, making the skin and the mucous membranes of the human body cavity a favorite for HPV. When the skin is infected with HPV, it develops “wart” – warts, which appear as round, oval or polygonal papules, fleshy bumps, and are light brown or yellowish-brown in color. HPV is like a cellular “spy,” but the paradox is that it does not aim to kill cells like HIV or hepatitis B. In June 2008, the results of a five-year epidemiological survey on HPV infection and cervical cancer among Chinese women showed that the prevalence of high-risk HPV infection among urban and rural women was 15.2% and 14.6%, respectively, and the infection peaked in the 20-24 and 40-44 age groups. The age groups of 20-24 and 40-44 years old showed the peak of infection. Among them, HPV types 16 and 18 are the most common causes of cervical cancer in Chinese women.
Globally, about 500,000 women are diagnosed with cervical cancer each year, and about 288,000 patients die. In China, about 135,000 new cases of cervical cancer are diagnosed each year, accounting for one-third of the global incidence and about 80,000 deaths as a result.
In 2006, a preventive vaccine for cervical cancer was finally approved by the US FDA for marketing after more than a decade of clinical studies. Cervical cancer may thus become the first malignancy to be prevented and eliminated through vaccination, screening and early diagnosis and treatment.