The human papilloma virus (HPV) is the most common viral infection of the genital tract.
General information
HPV is a group of viruses extremely widespread throughout the world. There are more than 190 types of this virus, of which at least 13 lead to the development of cancer (they are known as types of high risk). The human papilloma virus is transmitted mainly with sexual contacts, and most people are infected with them shortly after they begin to lead sex. Two types of HPV (16 and 18) cause 70% of all cases of cervical cancer (RSHM) and precancerous pathological states of the cervix.
The probability of getting sick
The human papilloma virus is transmitted mainly with sexual contacts, and most people are infected with them shortly after they begin to lead sex. But penetrating sex is not required to transfer the virus. Belly genital contact is a well -established path of transmission of papillomavirus infection. Risk groups of HPV infection are children and adolescents 15-18 years old.
The cervical cancer develops as a result of the acquired sexual means of infection with certain types of HPV. Risk factors for the development of RSM: the first sexual intercourse at an early age; Numerous sexual partners; Suppression of immunity (for example, HIV-infected people undergo an increased risk of HPV infection and are infected with a wider range of VPV types).
Symptoms and nature of the course of the disease
Most HPV infections do not lead to the appearance of symptoms or illness and pass themselves (about 90% pass within 2 years). However, a stable infection with certain types of HPV (most often with the types of 16 and 18) can lead to the development of precancerous pathological conditions. Without treatment, these conditions can develop into cervical cancer. Today, cervical cancer is the most common disease associated with the human papilloma virus. Cervical cancer is the fourth among the most common types of cancer in women, and the seventh in general: according to estimates, 528, 000 new cases in the world were in 2012.
RSM symptoms usually appear only at the advanced stage of cancer and may include the following:
- Irregular, intermenstrual (between menstruation) or pathological vaginal bleeding after sexual intercourse;
- Back pain, legs or in the pelvis;
- Fatigue, weight loss, loss of appetite;
- Unpleasant sensations in the vagina or discharge with an unpleasant odor;
- One swollen leg.
In the later stages, more severe symptoms may appear.
Papillomavirus infection is also involved in 20-90% of cases of plane cell cancer of the anus, oropharynx, vulva, vagina and penis. According to estimates, up to 90% of all cases of anal cancer are due to HPV-16 and HPV-18, and 40% of cases of vulva cancer, which is mainly found in elderly women, are associated with HPV-16.
HPV infection due to low risk types cause anogental warts in men and women (pointed condylomas or sexually transmitted warts). The average time between infection with the types of HPV-6 or 11 and the development of sexually transmitted warts is 11-12 months in men and 5-6 months in young women 16. Anogenital condylomas are difficult to treat.
HPV-6 and HPV-11 can also cause a rare condition known as recurrent respiratory papillomatosis (RRP), in which warts are formed in the larynx or other parts of the respiratory tract. RRP is observed mainly in children under the age of 5 years (juvenile PRP) or in people on the third ten life (adult RRP). In rare cases, women with genital HPV infection can convey the virus to the baby during childbirth. An absurd RRP can lead to a serious problem due to the obstruction of the respiratory tract.
Complications after the disease
It was established that RSM in 100% of cases is due to Oncogenic as the types of human papilloma virus (HPV). In women with a normal immune system, cervical cancer develops in 15-20 years. In women with a weakened immune system, for example, with HIV infection in the absence of treatment, its development may take only 5-10 years. Despite limited data on angeenital, cancer, different from the cervical cancer, an increasing number of actual data indicates the relationship of the human papillomavis with anus, vulva, vagina and penis. And although these types of cancer are less common than RSHM, their connection with HPV makes them potentially capable of preventing through the use of the same primary prevention strategies as for cervical cancer.
Types of HPV that do not cause cancer (especially types 6 and 11) can cause pointed condylomas and respiratory papillomatosis (a disease in which tumors grow in the respiratory tract leading from the nose and mouth to the lungs). And although these conditions are very rarely leading to death, they can often lead to a disease. Sharp condylomas are widespread and extremely infectious.
Mortality
There is a high global mortality from the cervix cancer (52%), the cause of which is the human papillomavirus. In 2012, approximately 270, 000 women died from RSM, and more than 85% of these deaths occurred in countries with a low and average income.
Treatment
RSM screening is testing for precancerous conditions and cancer among women who do not have symptoms and feel completely healthy. If screening reveals precancerous pathological conditions, they can be easily treated and thereby prevent cancer. Screening can also identify cancer at an early stage with a high probability of cure.
Given the fact that precancerous conditions have been developing for many years, every woman aged 30–49 years is recommended to undergo screening at least once in a life, and better often. Screening is effective for reducing mortality from cervical cancer only in the case of a significant number of women.
3 different types of screening are currently available:
- The usual Papanicolau test (PAP) and liquid cytology (LBC);
- Visual verification using acetic acid;
- Testing on the types of HPV high risk.
In developed countries, there are programs that provide women with opportunities for screening, which allows you to identify most precancerous conditions at the stages when they can be easily treated. Early treatment from the human papilloma virus allows you to prevent up to 80% of cases of RSM development in these countries.
In developing countries, limited access to effective screening means that the disease is often detected only in the later stages, when symptoms develop. In addition, the treatment of the disease in such later stages is ineffective, which leads to high levels of mortality from the RSM in these countries.
Vaccination effectiveness
The results of clinical trials indicate that the two vaccines existing today are safe and very effective in the prevention of HPV infection 16 and 18. Both vaccines are more effective if vaccination is carried out before the human papillomavirus is exposed. Therefore, it is preferable to carry out vaccination before the first sexual contact. Vaccines do not treat HPV infection or illness associated with HPV (such as cancer).
In some countries, the vaccination of boys against the human papilloma virus is introduced, taking into account the fact that it allows you to prevent genital cancer in both men and women, and one of the available vaccines also prevents the development of genital warts in men and women. In addition, the vaccination of boys serves to prevent the circulation of HPV in the population of adolescents and young adults. WHO recommends vaccination of girls aged 9-13 years, as this is the most effective, in terms of costs, a measure of public health against cervical cancer.
Vaccination against HPV does not replace screening to cervical cancer. In countries where the VPV vaccine is enacted, it may also be necessary to develop screening programs. By the end of 2013, the vaccine against the human papilloma virus was introduced in 55 WHO countries.
Modern mathematical models show that at the coverage of girls 12-13 years old, a full course of primary immunization (3 doses) with a vaccine against papillomavirus infection, it is possible to predict the risks of developing cervical cancer by 63%, cervical intraepithelial neoplasia of the third degree of severity (forerun)-by 51%, cytological disturbances in age corses to the age corses to the age of age. 30 years - by 27%.
Vaccines
Currently, there are two vaccines that protect from 16 and 18 types of human papillomavirus, causing at least 70% of the cervical cancer. These vaccines can also provide some cross protection against other, less common types of HPV causing RSM. One of these vaccines also protects from the types of HPV 6 and 11, which cause anogenital condylomas.
The development and registration of vaccines against papillomavirus infection determined the possibility of the primary prevention of the RSM.
The latest epidemics
Cervical cancer is the second most common type of cancer among women - according to estimates, 530, 000 new cases of disease are recorded annually, about 270, 000 patients are dying.
The incidence retains growth trend.
The probability of the disease of the CRM of each woman on average during her life is 0. 53%.
Historical information and interesting facts
In the mid -seventies of the twentieth century, the scientist Harold Tsur Hausen discovered that women suffering from cervical cancer are invariably infected with the human papillomavirus. In 1983, he discovered the DNA of papillomavirus in a cervical cancer biopsy, and this event can be considered the opening of the ONCOGENIC VPH-16 virus. In 2008, the Nobel Committee awarded the Nobel Prize in the field of physiology and medicine Harald Zur Hausen for discovering that the papilloma virus can cause cervical cancer.