Human papillomavirus - HPV
HPV stands for human papillomavirus. It is a pathogen associated with some STDs and causes warts on the skin and in the genitals area. Most infections can be successfully treated or even go out on their own without any symptoms. In rare cases HPV might lead to cancer. Men and women alike can get infected and transmit the disease.
HPV viruses literally inject their genetic material into a human cell, forcing it to produce more and more viruses. At some point the host cell breaks and dies releasing many viruses which continue to infect other cells.
It is important to know that not all papilloma viruses present an equal danger. Our immune system deals with most of them quite successfully.
How is HPV infection transmitted?
Many HPV viruses can be transmitted through skin to skin contact, especially the more harmless types that cause skin warts. Other types, that could cause condyloma or cervical cancer, are transmitted through sexual intercourse. They can also be transmitted through oral sex. Sharing a tub and close contact is quite rare but also possible way of getting an infection.
Mother to child transmission during childbirth has also been considered as a possibility in recent years. Recent studies show that infection cannot be transmitted through breastfeeding, kissing or blood transfusion.
Does HPV infection have any symptoms
In most cases HPV does not have any symptoms. That is why most people don’t realize they have been infected. But if any symptoms appear, they are manifested through typical changes on the skin and mucous membranes. Sometimes, though, signs and symptoms are so subtle that only a specialized test could determine an infection.
Unfortunately, there aren’t any early symptoms or perceptible signs when one is being just a carrier. Sometimes HPV might be detected in women with frequent vaginal infections and poor hygiene but there is no confirmed correlation between the two. There reason might be larger number of sexual partners, but this is not necessarily a predisposition as well. Symptoms also depend on the type of the virus. HPV type 6 and 11 that appear on the skin and mucouse membranes in the genital area also create masses resembling cauliflower called condylomas or genital warts.
With other types (16, 18, 33 and 35) there are small (around 1mm), thin grain-like warts around the infected area. As the infection progresses, these papillae gather on one place forming a similar to cauliflower mass that can measure up to several centimeters.
When and how the infection might turn out to be dangerous or carcinogenic is a difficult question. Of course, not all infections lead to malignant processes. Many people are carrying the virus throughout their whole life without developing a disease.
The reasons are many and diverse:
- local immunity;
- duration of the virus predisposition;
- virus serotype;
- other underlying factors.
Highly virulent and potentially carcinogenic for the cervix are serotypes 16 and 18 while 39 and 45 have low virulence. All the other serotypes do not cause changes leading to cancer.
When HPV infection has been diagnosed, everyone is considering what type of treatment to undergo or whether a treatment is necessary in the first place. There are methods and types of treatment. Drugs that destroy the infected cells or boost the immune system might be prescribed. Other methods include removing the damaged tissue through electrosurgery, laser surgery or cryotherapy.
Treatment is usually symptomatic – condylomas, precancerous or cancerous formations are being treated.
Dangerous HPV types causing cancer
200 HPV types are known till now. Most of them don’t have any symptoms or just cause harmless warts. Around 40 HPV types are related to infections in the genital area. They are categorized in groups based on their carcinogenic risk.
These HPV subtypes might lead to genital warts, but there is a small for them to develop into tumor. Type 6 and 11 as well as 40, 42, 43, 44, 54, 61, 62, 70, 71, 72, 74, 81 и 83 fall under that category.
They cause tissue changes – dysplasia and neoplasia. They can lead to cervical cancer as yeas go by. Certain papilloma viruses could also increase the risk of penile and throat cancer. The types presenting the highest risk in this group are 16 and 18. Others that are considered dangerous are 31, 33, 35, 39, 45, 51, 52, 56, 58, 59. It is possible that there might be others that haven’t been studied thoroughly.
Some types, such as 26, 53 and 66 are found in precancerous changes. The risk level with them is considered medium. 5 and 8 types fall under that category as well. They are dangerous when there is weak immune system at hand combined with the rare disease Epidermodysplasia verruciformis
What to do to prevent HPV infection
Preventing HPV infection is difficult due to several reasons:
- HPV viruses are quote common;
- Symptoms appear in just some cases;
- Viruses are easily transmitted.
Paying attention to your hygiene and keeping the immune system healthy is beneficial. To prevent the risk of common warts, avoid walking barefoot in public pools, saunas, dressing rooms and hotel rooms. Avoid sharing towels and shoes with people that have warts.
To prevent genital papilloma viruses, use condoms during casual sexual encounters. It is important to know that condoms do not provide 100% protection but they significantly decrease the risk of infection.
The safest measure is to maintain a monogamous sex life with a healthy partner that has never been diagnosed with the virus. All other methods have preventive role but do not provide 100% safety.
Every woman at a sexually active age should perform regular screenings – PAP tests. These screenings allow for early diagnosis and decrease the cervical cancer death risk by 70%.
Modern HPV diagnostics recommend combining PAP tests with DNA analysis which provides 100% accuracy in terms of sensitivity and specificity. DNA analysis detects the virus DNA directly in the DNA sample of the patient. It determines the HPV type and, respectively, the risk for developing neoplasia or cancer. It also establishes the stage of the infection and helps in determining the right treatment.
There are vaccines available for some of the most common HPV types – 6, 11, 16 and 18. It is administered three times – first at a random date, then 2 months after the first vaccine and finally 6 months after the initial vaccine. These vaccines prevent HPV infection with the types that cause cervical cancer and genital condylomas. It is designed for young girls and women (age 9-26) and must be administered before their first intercourse. Vaccines, though, do not replace the standard screenings – prophylactic check-ups and PAP test that aim to establish early stages of cervical cancer.
For women at the age of 20 and above, regular visits to an OBG doctor to perform PAP tests are recommended. This simple test allows for early detection of cervical cancer. The sample is taken and, adding some high percent alcohol, it is put on a laboratory glass slide. This test should not be confused with HPV detection tests. PAP tests aim to establish unusual cellular changes that might be caused by HPV infection but there might be other causes. To evaluate the possible changes, a scale developed by the Greek doctor George Papanicolaou (hence the name PAP test) is being used.
If they haven’t been sexually active, it is at the age of 18 that women should start the PAP screenings. Generally, PAP tests should start as soon as a girl or a woman starts being sexually active.
Recently, a liquid-based PAP test is being performed with the main difference being in sample taking, storage and processing. It allows pathologist to observe much more cells and thus achieve better accuracy. Since this is a more expensive test, doctors suggest it as a subsequent test when there’s been borderline results in the standard PAP test.
Colposcopy is a magnified examination of the cervix and vagina. A colposcope (a type of microscope) is used. It magnifies up to 40 times allowing the doctor to notice even small changes like bleeding from the cervix, vaginal wall or vulva.
Should there be any doubts after a PAP test or colposcopy, the doctor might perform a biopsy – taking a tissue sample. Depending on the location of the affected area, the tissue sample is curated and further examined.
This is a test designed to detect HPV and identifying its type. Its reliance has been tested and proved in medical practice. The test results aid in diagnosing a malignant cervical tumor or previous stages of the development of the tumor. This is a test that is not usually applied to other parts of the body.
HPV test comes in different forms. It is recommended for women 30 years of age or more in combination with PAP test for early cervical cancer detection. If a PEP test in younger women provides basis for concern, HPV test might also be in order to help in determining the treatment of precancerous lesions of the cervix.
HPV vaccines are highly effective
Vaccines are the most reliable protection against diseases associated with HPV. It has been used since 2007 in many countries worldwide. Millions of vaccines have been administered proving its effectiveness.
Vaccines not only prevent cervical cancer but genital warts as well. There are several vaccines available and there has been research indicating that the bivalent one not only provides 100% protection against the 2 types it is designed for, but also 93% for the other high-risk types. Countries like England and Australia, where the vaccines are widely used, have reported a significant decrease in cervical cancer rates.
Are there side-effects from the vaccine?
Gynecologists are positive that the fear of significant side-effects have no grounds. Usually there might be some redness around the place of administration. Also, it is recommended that patient lies down for a while because they might faint. There has also been reports of increased body temperature but that is not related to any ongoing harmful processes. But doctors agree on the safety of the vaccines and never has there been reported a direct correlation between the vaccine and a disease that appeared afterwards.