Human papillomavirus (HPV) affects epithelial cells and has a particle diameter of 55 nm. A characteristic feature is the proliferation of the skin epithelium, as well as mucous membranes. In the early stage, the pathogen usually affects the basal cells of the epithelium, causing microtraumas. enters them through. Localized papillomas usually occur on the skin of the neck, armpits, groin and genitals (usually), oral mucosa, and nasopharynx.
This virus may be asymptomatic for many years. For the detection of HPV, electron microscopy or molecular hybridization methods are used.
types of human papillomavirus
In humans, HPV is distinguished, which affects mucous membranes and skin. There are a large number of papillomavirus, low and high oncogenic risk species. It has been proven that oncogenic properties allow DNA to integrate into the genome of human cells. associated with capacity.
The virus is active in 10-20% of cases. Depending on its type, it can cause benign or malignant lesions. Some HPVs are not oncogenic. They lead to the appearance of warts and genital warts. The most common are HPV 6 andThere are 11.
HPV oncogenes are those that have a high risk of developing cancerous lesions, especially on the cervix or anus. In terms of skin, HPV 16 and 18 are more common, as well as HPV 5 and 8, causing skinCancer can occur. The most well-known form of HPV-induced cancer is cervical cancer. But men can also contract the papilloma virus, which in the worst cases causes cancer of the penis or anus.
Often women are faced with HPV 16 - this is a form in which intrasomal parasitism is observed, that is, outside the cell chromosome (benign). HPV 18 is characterized by a high risk of developing oncology - first of all, benignTumors are formed, which after a while turn into cancer. In this case the virus is small (up to 30 nm).
Different types of HPV infections cause:
- Cervical neoplasms;
- invasive or pre-invasive oncology;
- Genital warts of the urinary tract and genitals.
Ingestion of the pathogen into the body does not always lead to disease. It all depends on the predisposing factors: increased sexual activity, vitamin deficiency, pregnancy, hypothermia, endometriosis, smoking, alcohol abuse, etc. It should be noted that a viral infection can occur even in an organism with a good immune system.
Features of infection
Human papillomavirus is highly contagious. It is usually spread through direct contact with an infected person, skin-to-skin or mucous membrane-to-mucous membrane. In genital infections, it most often occurs during vaginal or oral sex. Partners or other STIs (sexually transmitted infections) increase the risk. Indirect transmission through objects, contaminated clothing or bedding is also possible, but rarely occurs.
In 7% of cases, mother-to-child transmission of the virus can occur during childbirth if the infection is active. The risk increases to 40% if you are infected with HPV 16 or 18.
Penetrating into the epithelium, violation of integrity, papillomavirus infection promotes the development of the lower layer of epithelial cells in the form of warts or warts. This form of the disease is contagious and quickly spreads to others. As a rule, warts andCondylomas do not cause metastases and often disappear spontaneously.
HPV Symptoms
The incubation period lasts 9 months (average 3 months). HPV can be present in the body without obvious symptoms. The virus can go undetected for months or even years. Even at this stage, it is contagious.
Skin warts usually occur in clusters and grow with itching. The two most common forms of papillomas are either brown, hard, raised with a broken surface (common wart) or flat and red (flat wart). Sharp warts are found on the soles or heels of the feet, tend to grow inward and are therefore often painful.
The causative agents of genital warts are on moist and warm parts of the body, so they are localized on folds and mucous membranes. They can cause symptoms such as itching or burning. Genital warts have an incubation period, that is, infection and onset of symptoms. The intervening time ranges from 3 weeks to 8 months.
There are several forms of genital warts caused by different pathogens:
- Genital warts. Yellow or red colored nodules that often stand in clusters and occur on the labia, vagina, penis, urethra, anal canal, and rectum. They are highly contagious.
- Flat warts. They appear as flat lumps and are mainly found on the female genital organs. They increase the risk of developing cancer.
- Giant warts (Buschke-Levenshtein tumours). They develop into giant formations, destroying the surrounding tissue. In rare cases, they can degenerate and give rise to squamous cell carcinoma.
Infection of the mucous membranes in the upper respiratory tract is also possible. The conjunctiva of the eye may be affected, resulting in a pinkish scaly growth. An asymptomatic course is more difficult to detect, which the doctor may prescribe only with acetic acid (which may cause discoloration of the warts). causes) or can be seen with the help of a microscope.
In addition, the virus can also reside in cells without any tissue changes. Then they talk about a latent infection, that is, the presence of pathogens, but without symptoms. This stage after infection is several weeks to several months. can last till
potential consequences
When infected, the virus enters the cells of the integumentary tissue of the skin and mucous membranes, settles in the nuclei of cell structures and multiplies there. Usually, such HPV infections go unnoticed and without any consequences. They heal on their own, as the immune system successfully fights off the pathogen.
However, some HPV types cause skin changes, ie growths. Possible forms include genital warts or warts and papillomas, which can affect, for example, the face, hands or feet.
The causes of tissue changes are mostly benign, but can also worsen and lead to cancer. For example, cancer can occur decades after HPV infection. Cancer of the external female genital organs (cancer of the vagina and vagina)), anal cancer, cancer of the penis and cancer of the mouth and throat (tumors of the head and neck) are also possible.
setting up diagnosis
A test for HPV infection is done in women as part of preventive visits to a gynecologist. During a gynecological exam, a swab is taken from the lining of the cervix, this is called the Papanicolaou test (cytological examination). The resulting material is then examined for tissue changes to determine precancerous status.
Alternatively, an HPV test may be performed, in which cell contents from a mucosal swab or tissue sample are tested in the laboratory for certain viruses. However, this only allows to prove infection of the affected area, But does not make a statement about whether tissue changes have occurred. Thus, an HPV test makes sense, especially when combined with a Pap test, and helps detect cancer precursors at an early stage. can help.
If the test is positive, it is not yet a cause for concern, as the infection does not always lead to cancer. Routine examination is recommended to detect tissue changes at an early stage. In contrast, a negative test resultDoes not allow us to claim whether there were any infections in the past that the body successfully fought.
For men, there is no prognostic test in which testing would be done routinely. If there is associated cancer, examination of the tumor can determine whether HPV infection is at the root of the cancer.
Specific DNA techniques are also used in laboratory diagnosis, such as real-time PCR. Anogenital warts caused by HPV types 6 and 11 are easily detected during a pelvic exam.
How to treat human papillomavirus
In most cases, the disease does not require treatment as it goes away on its own and then the virus is not detected. However, if it is not, the infection can last longer and persist for months or even years. Could stay.
To date, there is no way to have a systemic effect on this virus, which would make it possible to destroy it completely. However, treating the resulting warts reduces the number of viruses, so in many cases the immune system can fight off other viruses. can fight and thus get rid of them. In some cases, the pathogens survive and can cause recurrent symptoms.
Therapeutic tactics depend on the type of HPV and the associated picture of the disease:
- Plantar and genital warts can be treated with topical salicylic acid formulations.
- Cryotherapy is also a method often used for HPV. In this case, the wart is burned by freezing, using liquid nitrogen.
- Laser or electrocautery are equally applicable methods.
Since the frequency of relapse is quite high, it is advisable to regularly check yourself and use a condom, even several months after the sores have disappeared, so as not to infect the sexual partner.
For HPV cancer, treatment is more difficult. In cervical cancer, removal of the uterus, upper part of the vagina, and ovaries is often recommended. This may be supplemented with radiation therapy to rule out the possibility of recurrenceOther cancers caused by HPV are often treated with targeted therapy, such as radiation or chemotherapy.
It should be remembered that the operation is not a cardinal solution, but solves only a cosmetic problem, since after removal the virus is able to remain in the surrounding tissues and warts may reappear.
infection prevention
There are two vaccinations: divalent HPV 16 and 18 and quadrivalent HPV 6, 11, 16 and 18. Vaccination is recommended for all young girls 14 and older.
Vaccination does not protect against all types of HPV. Therefore, all women between the ages of 25 and 65, regardless of whether they have been vaccinated, are advised to have regular smear tests.
Timely detection and complete removal of genital warts reduces the risk of disease. The effectiveness of using condoms to prevent transmission of infection can significantly reduce the risk of developing this condition. A specific multivalent vaccine is the most promising method for the prevention and treatment of the early stages of the disease causing it.