Sexually Transmitted Infections
What Are They?
Human Papilloma virus (HPV)
What is HPV?
HPV infects the body inside and outside:
The human papillomavirus or HPV is one of the most common family of viruses in the world today. HPV is also the world's most common sexually transmitted infection and is transmitted by skin-to-skin (including sexual) contact. HPV infects cells inside and outside of the body. These include surfaces of the skin, lining of the mouth, tongue, throat, tonsils, vagina, penis, cervix, and anus.
Most people who get HPV don't have any signs or symptoms and may unknowingly spread the disease. HPV is not related to HIV (the human immunodeficiency virus, which can cause AIDS). However, people with HIV have weakened immune systems and are therefore likely to be infected with various germs, including one or more types of HPV.
Different health risks caused by different types
There are many different types of HPV viruses. Over 80 types of HPV have been reliably identified, but researchers believe there are likely over 200. Some types of HPV can cause common skin warts and plantar warts (warts on the soles of the feet), while over 30 other types of HPV affect the anogenital tract (on or between the anus and genitals).
Of those HPV types that can cause genital infections:
- Some types (such as 16 and 18) can cause pre-cancerous lesions, cervical cancer and other genital cancers and are referred to as carcinogenic or 'high-risk HPV types'.
- Other types (such as 6 and 11) can lead to genital warts and are referred to as 'low-risk HPV types' because they rarely cause cancer.
Skin warts
The most visible types of HPV are skin warts (common, plantar or flat) that develop on areas of the skin such as the hands, arms, legs and bottom of the feet. HPV infections of this type are very common, harmless, non-cancerous, and easily treated.
Genital warts
Not to be confused with skin warts, genital warts (also known as condylomata acuminatum) are mostly caused by HPV types 6 and 11. In women, genital warts can appear on the vulva, urethra, cervix, anus or thighs. In men, they can appear on the penis, scrotum, anus or thighs.
Pre-cancerous lesions
In women, HPV can infect cells on the vagina and cervix where they can't be seen. These lesions (medically known as dysplasia, or abnormal cells of the cervix) are considered to be a pre-cancerous condition. HPV is one of the most frequent causes of cervical dysplasia. There are three types of cervical dysplasia: mild, moderate and severe. Left untreated, dysplasia can progress to cervical cancer.
Cancers
Carcinogenic types of HPV cause most cervical cancers and 70% are caused by HPV types 16 and 18. These types may also be linked to oral and penile cancers. Research has shown a strong link between anal cancer and HPV 16.
Transmission and natural history of HPV
HPV is not transmitted by blood. The most common means of transmission is by skin-to-skin contact with the penis, scrotum, vagina, vulva, or anus of an infected person. Kissing or touching a partner's genitals with the mouth can also transmit HPV. Using a condom does not guarantee protection since the virus can be on an area of skin not covered by the condom.
HPV is usually acquired at a young age at the time of sexual debut, typically measured as the age of 'first intercourse'. Research shows that sexual debut for young Canadians (male and female) can be as young as 15 years of age and it has been reported that oral sex is practised by girls as young as 12 and 13 years old, regardless of their social or economic background.
Genital warts are very contagious and are spread during oral, vaginal or anal sex with an infected partner:
- Most people (66%) who have sexual contact with a partner infected by genital warts will develop warts themselves, usually within three months of contact.
- Genital warts can cause problems during pregnancy:
- Sometimes they get larger, making it difficult to urinate.
- They can make the vagina less elastic and cause obstruction during delivery.
- In rare cases infants born to women with genital warts develop warts in their throats - a potentially life-threatening condition for the child.
Genital warts may last for years and eventually go away. Even if this happens the HPV virus can remain dormant in the body and the manifestation can return at a later date. The natural course taken by an HPV infection varies over time and from one person to another:
- Genital warts can develop quickly inside or outside the vagina, usually within three months of contact with an infected person.
- Within one year of initial HPV infection, low-grade cervical dysplasia (CIN 1) may develop (CIN stands for cervical intraepithelial neoplasia and is a system of classifying cervical lesions: CIN 1 = mild, CIN 2 = moderate, CIN 3 = severe).
- In some women the HPV infection persists and can lead to the beginning stages of cancer (CIN 2-3) - this transformation is generally slow and can take anywhere from five years to a lifetime.
Symptoms - physical and psychological
Genital warts
Though usually painless, symptoms for genital warts include:
- Itching or burning sensation and occasional minor bleeding as a result of anal sex or bowel movement.
- The cauliflower-like growths are unsightly and embarrassing and associated with a high incidence of depression, sexual dysfunction and disruptions to long-term relationships.
Research conducted among people with visible genital warts and who were diagnosed with HPV reported feelings of:
- Depression, shame, guilt;
- Fear of rejection by their partner, loss of sexuality and enjoyment of sex.
Pre-cancerous lesions
Cervical dysplasia seldom causes any noticeable symptoms. It is usually detected through a Pap test (smear) or colposcopy. HPV infection has social and psychological consequences. Studies of women who have received abnormal Pap test results indicate that they often experience psychological consequences including:
- Anxiety, fears about cancer;
- Sexual difficulties;
- Changes in body image;
- Concerns about loss of reproductive functions.
Treatments and strategies for prevention
Vaccination against HPV
Vaccination to prevent the most common types of HPV infection and cancer of the cervix is now available in Canada. The Government of Canada has approved vaccination for females between the ages of 9 and 26, and studies show that the vaccination is 100% effective in stopping four types of HPV infection. These four types of HPV can cause:
- pre-cancerous changes and cancers of the cervix, vulva and vagina (types 16 and 18), as well as
- genital and anal warts (types 6 and 11).
These four types of HPV cause 70% of all cancers of the cervix and 90% of genital warts, and associated diseases such as cancers of the vagina and vulva. The HPV vaccination does not stop you from getting other sexually transmitted infections. Even when you have been vaccinated, you should always use a condom during sex to protect yourself.
Regarding treatment, unlike bacteria, viruses cannot be destroyed with antibiotics, and there is currently no medical cure to eliminate an HPV infection. Treatment depends on the type of HPV infection and in the case of cervical cancer the stage of development.
Genital warts
Trying to remove the visible warts does not always eliminate HPV and genital warts can reappear. Chemical treatment methods can be painful, embarrassing and may cause scarring. Two powerful chemicals (podophyllin and trichloroacetic acid) are capable of destroying external genital warts with direct application, but this must be repeated several times. A new product, Imiquimod cream, is now available and has had some success at stimulating the immune system to fight the virus.
Depending on the size, number of warts and where they are located, other methods for removal of external warts include:
- Cryotherapy (damaged cells are killed by freezing them with liquid nitrogen);
- Electrosurgery (passing an electric current through abnormal cells);
- Laser therapy (super heats and vaporizes abnormal cells).
Cervical cancer
Early-stage cervical cancer can usually be treated successfully. Options at this stage can include LEEP (loop electrosurgical excision procedure - the removal of tissue using a hot wire loop), laser therapy or cryotherapy. If the cancer has invaded deeper layers of the cervix and has spread to the uterus, more extensive treatment may be involved such as a radical hysterectomy with lymph node removal. Side-effects associated with this procedure include: inability to control urination, sexual problems, psychological stress, and swelling in the legs.
Later-stage disease kills by invading nearby tissues. There are some benefits from chemotherapy and radiation therapy. Disease that has spread beyond the pelvis is generally regarded as incurable since the survival rates are about one in five. Cervical cancer can be prevented through detection and treatment, but the ideal solution is to prevent the infection that causes it - HPV.
At present, it is almost impossible to break the chain of communicability by stopping unprotected sexual activity. Even when condoms are used, they cover only the penis (or the outer edge of the vagina in the case of the female condom) and other anogenital skin contact can occur. Also, some people are allergic to latex; they use condoms made of sheep intestine instead, but these condoms have pores large enough to let small bacteria and viruses such as HPV through.
Vaccination would be another prevention strategy that would dramatically change the HPV landscape. Researchers are currently working on vaccines to prevent HPV infections that can cause cervical cancer and genital warts.
Last MOctober 10, 2007dDate -->
