Human papillomaviruses appear in humans primarily in two forms: as warts on the skin, they are known to be an annoying but rather harmless condition. As viruses transmitted sexually or through other intimate contact, some types of human papillomaviruses can cause various forms of cancer, especially cervical cancer.
What are human papillomaviruses?
Human papillomaviruses, or HPVs for short, form a diverse group of DNA viruses. More than one hundred different virus types have now been described for this group of viruses. HP viruses are envelope-free and appear under the microscope as spherical structures. Inside the spheres is a double-stranded DNA. HP viruses belong to the so-called oncoviruses. These viruses can cause malignant degeneration of tissues and thus lead to cancer. About ten to 15 percent of all cancers worldwide can be attributed to human papillomaviruses and other oncoviruses.
Significance and function
When a healthy person comes into contact with a host of human papillomaviruses, the viruses are transmitted to the skin or mucous membranes. Some papillomaviruses, on the other hand, are transmitted primarily by sexual means to the vaginal and anal areas, but also to the oral cavity. HP viruses are among the most common sexually transmitted pathogens. Once the viruses have come into contact with a new host, they invade the epithelial cells of the skin and mucous membranes. About thirty of the more than one hundred species specialize in the skin and mucous membranes of the genital and anal areas. Once the viruses have penetrated the cells, they can remain there unnoticed for months or even years. Often an infection also runs without symptoms and heals unnoticed. However, HPV can also cause uncontrolled cell growth. The growths are usually benign and appear in the form of warts on the affected skin area. If intimate areas are affected, the viruses cause genital warts and other genital warts there. Since the infection often goes unnoticed, one hundred percent protection against infection with sexually transmitted papillomaviruses is only possible through abstinence. Condoms greatly reduce the risk of infection with HPV. However, HP viruses are transmitted via infectious skin areas, not via body fluids. Therefore, infection can occur through skin sites not covered by the condom. In rarer cases, other HPV types can also be transmitted via jointly used cups, towels and the like. Since 2006, the vaccine Gardasil has been approved in Germany for the prevention of common, dangerous forms of the human papillomavirus. It immunizes against HPV types 16 and 18 as well as eleven and six. Cervarix, a second vaccine covering types 16 and 18, has been available since 2007. Vaccination is recommended for girls and young women between the ages of twelve and 17 before their first sexual contact. There is no therapy for HPV infection. Only the resulting growths are treated. Possible treatments for the growths are local application of interferons and other cytokines. Larger growths caused by human papillomavirus may also require burns to the warts or surgery.
Diseases
It was the German physician Harald zur Hausen who discovered the connection between human papillomavirus infection and the development of cervical cancer. The cancer, known as cervical carcinoma in medical terminology, is caused by so-called high-risk HPV types. These include genotypes 16, 18, 31 and 33, and at least one of these high-risk types is found in almost every woman affected by this cancer. The so-called low-risk types, on the other hand, almost never directly cause the dangerous degeneration at the cervix. In addition to cervical carcinoma, the high-risk HPV types also promote cancers in the vaginal area, on the penis, on the anus or in the oral cavity. It is also suspected that human papillomaviruses are involved in the development of white skin cancer. Far more harmless are the warts caused by HP viruses. In the genital area, however, they can become unpleasant due to itching and burning. Particularly common genital warts are the so-called genital warts. These can appear months or years after infection. The search for the source of infection and the prevention of the transmission of human papillomaviruses is correspondingly difficult.If the warts can eventually be seen or palpated, the disease is already far advanced and requires surgical treatment. So if you suspect you have genital warts, it’s a good idea to see a proctologist early.
