HPV stands for Human Papilloma Virus (Papilloma Virus Humain or PVH in French, but very few people use the French term).
The Papilloma viruses are a family of viruses with a common tropism (a specificity to infect): the skin and the mucous membranes. More than a hundred of such viruses have been identified, around 40 of which can infect the genitals.
Amongst these, some are more “carcinogenic” than others:
- those known as High risk viruses (HR) or as potentially oncogenic viruses (for example, HPV 16 & 18). They are responsible for the occurrence of genital cancers, the most common of which is cervical cancer. However most of the time (in 80 to 90% of cases) the infection is temporary and spontaneously regresses because infected peoples’ immune systems clear the body of the virus (referred to as viral clearance = negative test results). Nevertheless, for various reasons the virus can persist*. This may lead to the development of precancerous lesions (sorts of small flat warts on the uterine cervix). If in turn these lesions remain, they can develop into cancer after a relatively long period of about 10 to 15 or even 20 years.
* One factor that can influence the persistence of the virus is the level of tobacco consumption. Smoking reduces the immune system’s defenses. Therefore by eliminating smoking the probability of virus persistence is reduced.
- the other non-high risk viruses are called low risk viruses such as HPV 6 & 11. They cause the development of external wartsalso known as exophytic condyloma (known as “rooster-comb”, venereal vegetation). These lesions are always benign but they can be aesthetically embarrassing, easily irritable and also very contagious.
How do you catch HPV?
Contamination is primarily sexual. It occurs generally soon after the initial sexual encounter.
It is estimated that most often the first sexual contact usually takes place between 18 and 25 years old.
A study of young students has shown that nearly 70% contracted the Papilloma virus within 2 years of their first sexual contact.
This does not mean that 70% of them will develop a lesion on the cervix, but simply shows that the virus is very, very common and therefore any sexually active person can contract it.
Subsequently nearly 90% of those infected will eliminate the virus spontaneously after 2 to 3 years, without any treatment, thanks to their natural immunity.
How do you know if you are carrying a Papilloma virus (HPV)?
Currently it is not yet recommended to systematically screen for the presence of the HPV virus, though it is possible that in the future, screening for cervical cancer will first include checking for any HPV infection, which is not a bad thing in itself, but only efficient if any HPV infection persists over time.
Several DNA tests have been developed in order to determine if one is a carrier of HPV. Growing HPV in a culture is not possible because it is not a bacterial infection.
Several tests are available commercially. Most often one finds HPV as part of a “cocktail” of high risk tests (these use molecular biology techniques, for example Hybrid Capture2 ® and HPV PCR test.
- A positive result indicates the person is a carrier of HPV. This does not necessarily indicate that the carrier also has a precancerous lesion (this virus can take years to progress from infection towards a precancerous lesion).
- A positive test result does not in itself carry any negative connotation. It is only if the virus is persistent that there is a risk to manage.
- Negative HPV results suggest the probability of developing lesions in the following 3 - 5 years is very rare.
Some international studies even suggest replacing the tradition smear test (cytology tests being less sensitive) with one of these HPV test which would enable knowing:
- if in the case of a positive HPV result, that one is at risk of developing a cervical lesion, thus leaving the traditional smear test to be studied by a cytologist at this stage.
- in the case of a negative result, then the smear test would not be necessary since the risk of a precancerous lesion is very small.
More recently, even more precise tests have been developed (Genotyping). They identify the precise genotype of the virus because some genotypes are more dangerous than others, for example HPV 16.
These HPV tests may represent the future for better monitoring of patients, particularly of those who have been vaccinated against certain strains of HPV.
Do we need protected sexual intercourse?Does the partner need a test?
If you are carrying a "simple" Papilloma virus infection (even high-risk viruses or potentially oncogenic ones) or if you carry a virus-induced lesion such as a CIN (cervical dysplasia), it is not usually necessary to use condoms, because you are already infected with the virus and the use of condoms does not change the natural course of the virus.
Basically, carrying HPV (simple) does not alter anything regarding your future nor that of your partner (except in case of exophytic lesions (see below). In principle there is no risk of virus retransmission once you are healed. However, if you smoke, it is strongly recommended that you cease tobacco consumption, as tobacco, even if doesn’t cause the infection, decreases the immune system defenses and favors the persistence of all types of Papilloma virus.
What is an exophytic condilomaor papilloma acuminata?
These are usually small external warts also called condyloma acuminata, rooster-comb, and also venereal vegetation. These lesions are always benign but they can be aesthetically embarrassing, easily irritable and moreover very contagious.
The latency period of this type of lesion is estimated to be around 6 months.
The lesions can appear on the woman's vulva (large and small lips), on the pubis, perineum or anus and anal canal, more rarely on the upper thighs, on the gluteal cleft, or even the urethra. It is also vital to verify the absence of internal lesions in the vagina or the cervix by performing a colposcopy. As regards males, lesions may appear on the penis sheath, the foreskin, urethra and possibly also on the peri-anal region or in the groin area.
These lesions are caused by low-risk Papilloma viruses HPV 6 or 11 which are effectively prevented with vaccination by the quadrivalent vaccine Gardasil ® that protects against HPV 6, 11, 16 & 18. However, this vaccine is only efficient before any lesions have developed.
- What are the treatments for HPV?
Appropriate treatment depends on the quantity and extent of the lesions:
When many lesions are present, immunostimulatory treatments such as imiquimod (aldara®) are proposed. Should this not be successful then treatments targeting the destruction of the virus using laser, electrocoagulation etc. is proposed.
Sometimes several different treatments are required.
- Should one avoid unprotected sex? Even though condoms don’t protect completely against this type of lesions, which can be present on exposed areas, it is recommended to use a condom during sex until completely healed.
- Does smoking make this type of lesions worse?
Although tobacco smoking is not a direct contributory factor, it does reduce the immune system’s defenses and so the HPV virus can persist.
How to avoid an HPV infection?
If one abstains from sexual intercourse the probability of contracting HPV viruses is very slight or even zero. People without a sexually active history are in principle “naive” vis-à-vis HPV viruses.
In this context “naive” indicates that the immune system has not come into contact with the HPV viruses and has not developed a specific defense response.
Preventing infection by a Papilloma virus, (apart from abstinence) therefore requires a vaccination. The vaccination process is all the more efficient when given to “naive” subjects (they have not been in contact with the Papilloma viruses). Thus early vaccination of young girls who have not yet had sexual intercourse has the advantage of beating the virus before it has had a chance to infect.
In France this is how the HPV vaccination is recommended:
The first target group for the Papillomavirus vaccine includes all girls aged 9 to 14 and the next target group is all young women under 19
This policy is to target the vaccination where it has most efficacy; those who have not yet been in contact with any strain of the virus.
The vaccine stimulates the production of antibodies which prevents the virus entering the cells around the genitalia. However, once the virus is established the antibodies cannot prevent its development, hence the advantage of vaccinating the “naive” population cohorts.
These vaccines do not work with all Papilloma viruses:
The bivalent Cervarix vaccine (GSK laboratories) targets HPV 16 & 18.
The quadrivalent Gardasil® vaccine (MSD Sanofi-Pasteur laboratories) targets HPV 6, 11, 16 & 18.
When we remember that HPV 16 & 18 are responsible for between 70-80% of cervical cancer cases in France and throughout the world, then vaccination cannot protect against all types of cancerand therefore screening must continue includingmonitoring of the vaccinated population.