Human papillomavirus infection in the context of "Fomite"

Cervical cancer is a type of cancer that develops in the cervix or in any layer of the wall of the cervix. It is due to the abnormal growth of cells that can invade or spread to other parts of the body. Early on, typically no symptoms are seen. Later symptoms may include abnormal vaginal bleeding, pelvic pain or pain during sexual intercourse. While bleeding after sex may not be serious, it may also indicate the presence of cervical cancer.

Virtually all cervical cancer cases (99%) are linked to genital human papillomavirus infection (HPV); most who have had HPV infections, however, do not develop cervical cancer. HPV 16 and 18 strains are responsible for approximately 70% of cervical cancer cases globally and nearly 50% of high-grade cervical pre-cancers. Minor risk factors include smoking, a weak immune system, birth control pills, starting sex at a young age, and having many sexual partners. Genetic factors also contribute to cervical cancer risk. Cervical cancer typically develops from precancerous changes called cervical intraepithelial neoplasia over 10 to 20 years. About 75% of cervical cancers are squamous cell carcinomas, 20-25% are adenocarcinoma, 3% are adenosquamous carcinomas, and less than 1% are small cell neuroendocrine tumors of the cervix. Diagnosis is typically by cervical screening followed by a biopsy. Medical imaging is then done to determine whether or not the cancer has spread beyond the cervix.

Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms of cancer include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans.

About 33% of deaths from cancer are caused by tobacco and alcohol consumption, obesity, lack of fruit and vegetables in diet and lack of exercise. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. Infection with specific viruses, bacteria, and parasites causes approximately 16–18% of cancers worldwide. These infectious agents include Helicobacter pylori, hepatitis B, hepatitis C, HPV, Epstein–Barr virus, Human T-lymphotropic virus 1, Kaposi's sarcoma-associated herpesvirus and Merkel cell polyomavirus. Human immunodeficiency virus (HIV) does not directly cause cancer, but it causes immune deficiency that can increase the risk of cancer from other infections, sometimes up to several thousandfold (in the case of Kaposi's sarcoma). Importantly, vaccination against the hepatitis B virus and the human papillomavirus have been shown to nearly eliminate the risk of cancers caused by these viruses in persons successfully vaccinated prior to infection.

Oropharyngeal cancer, also known as oropharyngeal squamous cell carcinoma and tonsil cancer, is a disease in which abnormal cells with the potential to both grow locally and spread to other parts of the body are found in the oral cavity, in the tissue of the part of the throat (oropharynx) that includes the base of the tongue, the tonsils, the soft palate, and the walls of the pharynx.

The two types of oropharyngeal cancers are HPV-positive oropharyngeal cancer, which is caused by an oral human papillomavirus infection; and HPV-negative oropharyngeal cancer, which is linked to use of alcohol, tobacco, or both.

Oral cancer, also known as oral cavity cancer, tongue cancer or mouth cancer, is a cancer of the lining of the lips, mouth, or upper throat. In the mouth, it most commonly starts as a painless red or white patch, that thickens, gets ulcerated and continues to grow. When on the lips, it commonly looks like a persistent crusting ulcer that does not heal, and slowly grows. Other symptoms may include difficult or painful swallowing, new lumps or bumps in the neck, a swelling in the mouth, or a feeling of numbness in the mouth or lips.

Risk factors include tobacco and alcohol use. Those who use both alcohol and tobacco have a 15 times greater risk of oral cancer than those who use neither. Other risk factors include betel nut chewing and sun exposure on the lip. HPV infection may play a limited role in some oral cavity cancers. Oral cancer is a subgroup of head and neck cancers. Diagnosis is made by sampling (biopsy) of the lesion, followed by an imaging workup (called staging) which can include CT scan, MRI, PET scan to determine the local extension of the tumor, and if the disease has spread to distant parts of the body.

Genital warts are a sexually transmitted infection caused by certain types of human papillomavirus (HPV). They may be flat or project out from the surface of the skin, and their color may vary; brownish, white, pale yellow, pinkish-red, or gray. There may be a few individual warts or several, either in a cluster or merged together to look cauliflower-shaped. They can be itchy and feel burning. Usually they cause few symptoms, but can occasionally be painful. Typically they appear one to eight months following exposure. Warts are the most easily recognized symptom of genital HPV infection.

HPV types 6 and 11 are responsible for causing majority of genital warts whereas HPV types 16, 18, 31, 33, and 35 are also occasionally found. It is spread through direct skin-to-skin contact, usually during oral, manual, vaginal, or anal sex with an infected partner. Diagnosis is generally based on symptoms and can be confirmed by biopsy. The types of HPV that cause cancer are not the same as those that cause warts.

Human papillomavirus (HPV) vaccines are vaccines intended to provide acquired immunity against infection by certain types of human papillomavirus. The first HPV vaccine became available in 2006. Currently there are six licensed HPV vaccines: three bivalent (protect against two types of HPV), two quadrivalent (against four), and one nonavalent vaccine (against nine) All have excellent safety profiles and are highly efficacious, or have met immunobridging standards. All of them protect against HPV types 16 and 18, which are together responsible for approximately 70% of cervical cancer cases globally. The quadrivalent vaccines provide additional protection against HPV types 6 and 11. The nonavalent provides additional protection against HPV types 31, 33, 45, 52 and 58. It is estimated that HPV vaccines may prevent 70% of cervical cancer, 80% of anal cancer, 60% of vaginal cancer, 40% of vulvar cancer, and show more than 90% effectiveness in preventing HPV-positive oropharyngeal cancers. They also protect against penile cancer. They additionally prevent genital warts (also known as anogenital warts), with the quadrivalent and nonavalent vaccines providing virtually complete protection. The WHO recommends a one or two-dose schedule for girls aged 9–14 years, the same for girls and women aged 15–20 years, and two doses with a 6-month interval for women older than 21 years. The vaccines provide protection for at least five to ten years.

The primary target group in most of the countries recommending HPV vaccination is young adolescent girls, aged 9–14. The vaccination schedule depends on the age of the vaccine recipient. As of 2023, 27% of girls aged 9–14 years worldwide received at least one dose (37 countries were implementing the single-dose schedule, 45% of girls aged 9–14 years old vaccinated in that year). As of September 2024, 57 countries are implementing the single-dose schedule. At least 144 countries (at least 74% of WHO member states) provided the HPV vaccine in their national immunization schedule for girls, as of November 2024. As of 2022, 47 countries (24% of WHO member states) also did it for boys. Vaccinating a large portion of the population may also benefit the unvaccinated by way of herd immunity.