The human papillomavirus, known by the acronym HPV is a virus transmitted through sexual contact, can cause genital warts and cervical cancer, anus, penis and oropharynx.
Each year, about 270,000 women worldwide die from tumors account in the cervix caused by HPV.In Brazil, it is estimated that annually there are about 15,000 new cases of cervical cancer.
In this article we will talk about the HPV vaccination, as has been implemented in the immunization schedule in many countries in recent years.
If you are looking for information about HPV or genital wart, follow the links:
Before we go on, check out this short video, produced by MD.Saúde team, explaining simply the HPV vaccination.
There are about 150 subtypes of human papillomavirus, or all able to induce malignant tumors or warts.Of these 150 types, 12 of them cause genital warts, and HPV-6 and HPV-11 subtypes most common, accounting for 90% of cases.15 types of HPV cause cervical cancer, penis, anus and oropharynx cancers, with HPV-16 and HPV-18 subtypes the most dangerous.
In relation to cancer, plus 70% of cases are caused by HPV-16 or HPV-18, which is why these two subtypes are the targets of currently available vaccines.
HPV VACCINES ON THE MARKET
They exist on the market two distinct HPV vaccines.The quadruple vaccine, called Gardasil, currently available for free in the public health system in many countries, acts against subtypes 6, 11, 16 and 18. This vaccine thus protects against the human papillomavirus subtypes that cause cancer and more more cause genital warts.
The other vaccine available in the market but not in public service, is Cervarix, a double vaccine (bivalent) that protects against subtypes 16 and 18. This vaccine acts against HPV that cause cancer, but not about the HPV that cause warts genitals.
In Brazil, since the beginning of 2014, the Ministry of Health has made available on the NHS to quadruple vaccine for girls between 9 and 13 years old.
WHO SHOULD BE VACCINATED AGAINST HPV
The HPV vaccine has been developed in order to reduce cases of cervical cancer in women.However, it is an important cause of penile and anal cancer, accounting for about 40% of cases, HPV vaccination can also be made in men.
Currently, it indicates the administration of quadruple vaccine against HPV for men and women between 9 and 26 years.In selected cases, when the doctor finds that vaccination will bring real benefits to the patient, the vaccine may also be indicated for people over 26 years.
From a public health perspective, however, mass immunization of the population is made differently.As penile cancer or anal tumors are much less common than cervical cancer, and how the HPV vaccine is much more effective if taken by people who have never been exposed to HPV, preferably children who have not started your life sex in many countries, including Brazil, the immunization schedule only indicates vaccination in girls between 9 and 13 years old.
This does not mean that men and women under 26 can not use the private health system to be vaccinated if their doctors understand that vaccination is important.
Have already been previously infected with an HPV subtype does not contraindicate the holding vaccination.If a woman is or has been infected with HPV-18, for example the quadruple vaccination serves to prevent it against the other three subtypes of human papillomavirus.
Currently, due to lack of studies proving their safety for the fetus, the HPV vaccination is not recommended for pregnant women.On the other hand, during breastfeeding no contraindications.
As the vaccine is made with inactive virus, it can be given to people with HIV or other causes of immunosuppression.
HPV VACCINATION EFFECTIVENESS
When taken in childhood, before the onset of sexual experience, vaccination has an efficiency of almost 100% in the prevention of malignant tumors of the cervix caused by the subtypes 16 and 18. When administered to women older, already sexually active and therefore at greater risk of have been previously exposed to HPV, the effectiveness drops to only 44%.
In men never exposed to HPV vaccine efficacy is somewhat lower than in women, but still reaches 90%.
Vaccination when done in women who are already infected with HPV-16 or HPV-18 apparently does not cause damage, but does not provide any beneficial effect on the current infection.Importantly, the vaccine is to prevent HPV and not to treat it.
Currently, we do not know how long the vaccine confers immunity.How vaccines are relatively new in the market, most people under study does not have 8 years of vaccination.So, to know how long a person will be immune to HPV after vaccination will be even more necessary a few years of studies.
Contrary to what occurs in many infectious diseases, there are no post-vaccination serological tests for HPV, or blood tests that serve to measure the blood concentration of antibody against human papillomavirus after vaccination.
Among the major scientific studies that prove the effectiveness of the HPV vaccine, we highlight 3 of them:
-The FUTURE II trial- A study published in the New England Journal of Medicine, with 12,000 women between 15 and 26 years, double-blind, randomized, multicenter, placebo-controlled study.The quadrivalent vaccine was 98% effective in preventing cases of CIN 2, CIN 3, adenocarcinoma in situ, or cancer of the cervix.
-The FUTURE first trial- also published in the New England Journal of Medicine.Study of 5,455 women aged 16 to 24 years, double-blind, randomized, multicenter, placebo-controlled study.The quadrivalent vaccine was 100% effective in preventing anogenital warts, vulvar and vaginal cancers, NIC1, CIN 2, CIN 3 and adenocarcinoma in situ.
-PATRICIA (Papilloma trial against cancer in young adults)- Published in the Lancet.Study of 18,000 women between 15 and 25 years, double-blind, randomized, multicenter, placebo-controlled study.The bivalent vaccine showed 93% efficacy in preventing cases of CIN 2, CIN 3, adenocarcinoma in situ or cervical cancer.
HPV VACCINE DOSES
The quadruple vaccine is typically administered in 3 doses.The patient takes the first vaccine today and receiving two ribs after 2 and 6 months (call doses at 0, 2 and 6 months).In Brazil and some other countries that have adopted the quadruple vaccine in the official calendar the scheme has been done a little differently.The second dose has been recommended at 6 months interval and the third only after 5 years (after 0, 6 months and 5 years).
The bivalent vaccine is also usually administered in 3 doses at 0, 1 and 6 months.
PAP IN WOMEN VACCINATED
Have been vaccinated against HPV considerably reduces the risk of cervical cancer, but not away at 100%.First because the vaccine only covers the two most dangerous subtypes of HPV;second because some women may already be infected with any HPV type at the time of vaccination, with no effect of the vaccine on this infection already underway;and third because there are cases unusual, yes, of cervical cancer not caused by HPV.
Therefore, in no way exempts vaccination woman to do your routine Pap test.
SIDE EFFECTS OF HPV VACCINE
Despite some rumors that every now and then circulate among the population, the HPV vaccine is safe.Profile of serious side effects is similar to other vaccines present in the immunization schedule.
Unfortunately, every time there is a new vaccine, spread on the Internet and social networks obscurantist campaigns on the risks of vaccination, they only serve to alarm the population and boycotting vaccination campaigns.
Always remember that just like any vaccine, vaccination against HPV can cause mild side effects such as pain at the injection site, headache, dizziness and nausea.As the vaccine will be administered to millions of people, it is natural that in the months and years are reported several cases of mild side effects.But this does not mean that the vaccine is dangerous and should not be taken.Several other vaccines present in the immunization schedule for decades also feature frequent mild side effects.
Just as an example, an American study showed that between 2006 and 2013 were administered over 57 million doses of quadrivalent vaccine.The number of cases reported adverse events was approximately 21 thousand, or 0.03% of vaccinations.Of these 21,000, 19,000 were mild side effects such as pain at the injection site.In the remaining 2,000 cases considered moderate to severe (0.003%), most have been nausea, vomiting, malaise, headache, dizziness, hypotension, fever, fainting and generalized weakness.
By 2011, 34 deaths had been reported after administration of the vaccine.However, in none of them was able to establish a direct relationship with the patient indeed have been vaccinated recently.
There is also no evidence that the HPV vaccine increases the risk of the occurrence of Guillain-Barré syndrome.
Two side effects, however, seem to be more common in HPV vaccine than other vaccines syncope (fainting) and venous thrombosis.Yet, of the 31 reported cases of venous thrombosis of the lower limbs, 29 occurred in patients with risk factors for thrombosis, such as use of hormonal contraceptives or history of coagulation disorders.
The low but real risk of fainting, it is suggested that the patient be at rest 15 minutes after vaccination.
WHAT IS HPV - SYMPTOMS, TRANSMISSION AND TREATMENT
HPV is responsible for the appearance of common warts of the skin and genital warts, also known as condyloma acuminata or rooster combs.But what makes HPV a great medical relevance virus is the fact that he is related to virtually 100% of cases of cervical cancer of the uterus, the most common types of cancer in the female population.
In this article we will explain what the HPV virus, how it is transmitted, what are its symptoms and complications, which are the treatment options and their chances of a cure.
WHAT IS HPV
HPV is a virus that infects only human and attacks the skin and epithelial cells of the mucosa.The effect of the virus on the cells of the skin favors the formation of tumors, and benign mostly small, such as the common skin warts and genital warts.However, when the infected area is the mucosa of the cervix, vagina, penis or anus, the virus can induce the formation of malignant tumors, generating, for example, cervical cancer, and anal cancer.
There are more than 150 subtypes of HPV.Each virus subtype has attracted to a particular area of the body.For example, the HPV and HPV-2 are associated with four common skin warts while HPV-1 which causes warts preferably affect the soles.Since HPV-6 and HPV-11 are related to the development of genital warts.The cervical cancer can be caused by several subtypes, as we shall see, but most cases occur when a woman is infected with HPV-16 or HPV-18.
CANCERS RELATED TO HPV
As already mentioned, which makes HPV a serious public health problem is its ability to cause some cancers.99% of cervical cancers, 93% of anal cancers, 60% of vulvar cancers and 50% of penile and vaginal cancers are related to HPV infection.Rarely, HPV is also capable of causing cancer of the larynx, mouth, sinuses and esophagus.
Among all these mentioned cancers, cervical cancer is triggered the most common reason is much more often hear talk about your association with HPV than for other types of cancer.
However, it is important to note that not every HPV infection leads to the formation of a malignant tumor.Among the more than 150 known HPV subtypes, few are considered more hazardous as subtypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68, while others are less aggressive with low risk of malignant transformation, such subtypes 6, 11, 40, 42, 43, 44, 53, 54, 61, 72, 73 and 81.
In fact, around 70% of cases of cervical cancer are caused by only two subtypes, 50% HPV-16 and HPV-20% 18.HPV-16 is also behind most cases of anal cancer, penile, vaginal, vulvar and some types of oropharyngeal cancer, which is therefore the most dangerous HPV subtype for both men and women.
In addition the HPV subtype, another important factor for the generation of a malignant tumor is the time of infection.Most people infected with HPV can get rid of the virus spontaneously after 1 or 2 years.To do so, just have an immune system able to cope with HPV.About 10% of infected individuals, however, develop what we call persistent infection.These are the people who have the highest risk of having cancer.
The HPV need 10-20 years to be able to cause cellular changes that generate a malignant tumor.Therefore, screening tests of cervical cancer, as the famous Pap test (preventive gynecological exam), it is essential for us to identify the occurrence of premalignant changes that arise years before the malignant tumor appears.
HPV TRANSMISSION METHODS
HPV that infect the skin and cause common warts are normally contracted when there are small skin lesions such as cuts or scratches which allow the virus invasion into the body.The transmission is therefore with skin contact with skin.
The HPV subtypes that cause common warts are not related to cancers that occur in the mucosa of the genitals, anus or cervix, as they are unable to infect the region.The opposite is also true, as the subtypes that usually cause damage to mucous usually not attack the skin.
However, there are some exceptions to the above rule.Some subtypes able to cause warts on the skin can also possibly cause genital warts, such as HPV-1, HPV-2 and HPV-4.These subtypes, but rarely cause genital warts and when they do have low capacity to generate malignant tumors.
The contagion of the mucous membranes of the vagina, vulva, anus, penis and cervix is through sexual contact.Many do not know, but the HPV infection is the most common sexually transmitted disease in the world, often more than AIDS, gonorrhea, syphilis, or any other known STD.
Transmission of HPV through oral sex is possible, but is far less common than transmission through vaginal or anal sex.Some cancers of the oropharynx, larynx and esophagus are related to this type of contamination.
Except for sharing sexual objects, transmission of HPV other inanimate objects such as towels, bed linen or underwear, does not seem to occur.Similarly, you can not catch HPV in public bathrooms, swimming pool, sauna or beach.
SYMPTOMS OF HPV
As explained above, each HPV subtype has a preference for a certain area of the body:
Subtypes 1, 2, 4, 26, 27, 29, 41, 57, 65 and 75 to 78 tend to cause common skin warts.
The subtypes 3, 10, 27, 28, 38, 41 and 49 also cause warts on the skin but are generally called flat warts.
Subtypes 1, 2, 4, 60, 63 cause warts on the soles of feet.
Subtypes subtypes 1 to 6, 10, 11, 16, 18, 30, 31, 33, 35, 39 to 45, 51 to 59, 70 and 83 can cause genital and anal warts (condyloma acuminata).Note: 90% of cases of genital warts are caused by subtypes 6:11.
HPV-16 and HPV-18, which are those more related to cervical cancer do not usually cause any symptoms.The vast majority of women infected with HPV do not even suspect who has the virus.The diagnosis of infection usually occurs through preventive gynecological examination.
DIAGNOSIS OF HPV
In the case of skin or genital warts, HPV diagnosis is clinical, using a simple physical examination.Just identify the presence of the wart, are not required other tests.In the specific case of genital warts, despite the diagnosis of HPV be obvious, it is important that (a) patient is tested (a) for other STDs, it is very common for a person to have more than one STD at the same time.
Since the diagnosis of HPV in women with uterine cervix infected is more complex.There are symptoms and not always found in the Pap smear are characteristic of HPV infection.For the presence of the virus, the gynecologist needs spoon during pelvic examination a small sample of cervical material and inside the vagina.This material is sent to the laboratory so that it can look for the presence of HPV.If HPV present, the laboratory is able to provide information on the subtype of the virus responsible for the infection.
TREATMENT OF HPV
As previously mentioned, about 90% of HPV infections to heal themselves after 1 or 2 years.
In fact, HPV has a curious feature: it is an infection that has no treatment but no cure.There are no drugs to kill the virus or accelerate the healing process.The only option is to wait for the immune system to eliminate virus spontaneously over time.
In patients who develop warts, treatment is only for the removal of the lesion.When the wart is removed it does not mean that the virus has been eliminated from the body.The patient remains infected and can develop new warts while HPV is present.
The situation is equal to the women who develop pre-malignant lesions (intraepithelial neoplasia) uterine cervix.When a premalignant lesion is identified, the gynecologist to surgically remove, but that does not mean that the patient was cured of HPV.If it remains infected, new potentially malignant lesions may arise over the years.
Human papillomavirus, better known by the acronym HPV is a virus that can be transmitted by sexual contact or by direct contact with skin.
Despite being an important prevention measure, condoms are not 100% effective against HPV transmission.This is because the virus may be present in areas of the genitalia that are not covered by the condom.
To be real prevention of infection, the best option is the vaccine.There are two HPV vaccines, one that protects against subtypes 16 and 18, the most dangerous for cancer of the cervix, and another that protects against subtypes 16, 18, 6 and 11, effective against cervical cancer uterus and against genital warts.
HPV vaccines are very effective, with success rates above 95%, especially when administered in young girls who have not started their sex life and therefore never had contact with the HPV virus.
Despite the frequent obscurantist and slanderous campaigns that try to disqualify the importance of vaccination, the fact is that the HPV vaccine has solid scientific basis, both on the issue of efficacy and the safety.
Cervical cancer, also called cervical cancer, uterine cervix cancer or cervical cancer is the second most common cancer in women, second only to breast cancer.More than 90% of cervical malignancies are caused by HPV virus, a sexually transmitted infection by and currently preventable by vaccination route.
In this article we will talk about the relationship of HPV with cervical cancer.
WHAT IS HPV
The human papillomavirus, or human papillomavirus, known as HPV, is a virus that has more than 150 subtypes.The HPV virus only causes disease in humans, and is responsible for the appearance of common warts of the skin and genital warts, also called condyloma.In this text we will talk only of HPV related cervical cancer, if you want to learn about HPV and common and genital warts.
Although warts are a very common skin change, which makes HPV a serious health problem is its association with cervical cancer.Among the approximately 150 known subtypes, two of them are present in over 70% of cases of cervical cancer: HPV-16 and HPV-18.HPV is also associated with the occurrence of other cancers such as cancer of the penis, vagina, vulva and anus.
Importantly, when we speak of HPV linked to cancer of the cervix we are referring to a statistical risk.Being infected with HPV, mainly by two subtypes mentioned above, substantially increases the risk of developing uterine cancer but does not mean that the patient must develop a cancer.In fact, most women infected with HPV will not have cancer.
HPV is a virus transmitted through sexual contact and is actually the most common sexually transmitted disease in the world .It is estimated that up to 10% of the world population is infected with the virus and 50% of women (and men) have contact with it at some time in their lives.
HPV HAS NO CURE?
Most cases of HPV infection are asymptomatic and transient.After two years, 80-90% of patients are cured spontaneously, just by the action of your immune system.Therefore, for most women, HPV curable, and it occurs without any treatment.
Problems arise in the remaining 10 to 20% who can not get rid of HPV and develop permanent infection.These are patients who are at risk of developing cervical cancer.
Generally, it takes about 20 years of infection for the human papillomavirus can cause cervical cancer.For this reason, regular screening test with the gynecologist is important for early detection of malignant lesion signal in development (more on the Pap smear below).
ASSOCIATION BETWEEN HPV AND CERVICAL CANCER
There are 15 subtypes of HPV that are considered high risk for cancer of the cervix.However, as mentioned above, at least 70% of cancer cases are caused solely by HPV-16 and HPV-18 subtypes.The longer a woman remains infected with HPV, the greater the risk of it getting cancer.
Cigarette smoking increases the risk of cervical cancer caused by HPV, which is why every woman infected by the virus has proven yet another reason to quit smoking .
Another important risk factor is co-infection with HIV .The association between HIV and HPV not only further increases the risk of cervical cancer, as is often cause extremely aggressive tumors that spread rapidly through the body.
PAP TESTING AND DIAGNOSIS OF CERVICAL CANCER
The Pap test, also known as Pap smear, is currently the manner indicated for the screening of cervical cancer.
The Pap test is not meant to diagnose cancer, who makes the diagnosis is biopsy of the cervix.The Pap smear is just a screening test, that is, it only helps the doctor identify which women are at greater risk that need to be submitted to colposcopy and biopsy.
The Pap test is done during the pelvic exam with the help of a vaginal speculum (duck-billed).The gynecologist view the cervix and through a wooden spatula and a brush, crop material from the region.The collected material contains cells of the cervix, which are sent for microscopic evaluation to detect premalignant lesions and malignant lesions still in early stages.The collection of material also serves to carry out research of HPV and other infections such as chlamydia, gonorrhea, syphilis, Gardnerella, etc.
In general, it is recommended preventive examinations annually on all sexually active women.If the Pap identify cells with pre-malignant characteristics, the patient must be submitted to biopsy of the cervix.
WHAT IS CIN (CERVICAL INTRAEPITHELIAL NEOPLASIA)
The cervical intraepithelial neoplasia (CIN) is a premalignant lesion, which can be identified by biopsy of the uterine cervix.The NIC is not a cancer, but an injury to the cervical tissue at high risk of turning into one.Depending on factors such as size and location of the lesion and subtype of HPV type detected, cervical intraepithelial neoplasms are divided into three groups, in order of increasing risk of malignant transformation: CIN 1, CIN 2 and CIN 3.
Most cases of CIN 1 spontaneously heal in a period of up to two years, not needing more aggressive treatment.The cases of CIN 2 and CIN 3 also heal by themselves too often, however, as the risk of progression to cancer is higher, these injuries need to be addressed.
If the biopsy to detect the presence of a CIN 2 CIN 3 or injury, the most suitable is to make the area of excision which no pre-malignant changes of cells.Importantly, the excisions remove only the portion of the tissue with the risk of malignant transformation, but continue HPV present in the body.We remove only the region where the tissue is composed of cells that can, in the long term, turn into cancer.
If the biopsy to identify the presence of a cervical cancer of the uterus already established, it is necessary to carry out further tests, identifying the presence of metastases.Usually begins with a CT scan of the pelvis and abdomen.
In those people who develop permanent HPV infection, that is, the immune system is not able to eliminate viruses, there is no curative treatment available.These people are infected with the virus for life, being always at risk for malignant lesions, especially if they are HPV-16 or HPV-18.Therefore, the advent of the vaccine was an important step in the fight against cervical cancer, as this prevents contamination of people not yet infected.
There are two HPV vaccines: one includes the subtypes 6, 11, 16 and 18, and another 16 and 18. Therefore, the vaccine includes the main, but not all subtypes related to cervical cancer.This means that vaccination does not eliminate the need for annual Pap smear since it does not in 100% the risk of cancer.Vaccination is performed in three steps, the second and third doses 2 and 6 months after the first.
The vaccine has been shown from 9 years old and should preferably be offered to girls not sexually active.Remember that the vaccine is prevention rather than treatment of HPV.No use vaccinate those who have had contact with HPV.For this reason, vaccination in women over 26 years does not have the same protective effect, since many of the patients were already exposed to HPV during their lifetime.
Those in favor of vaccination in older women argue that even if the vaccine does not serve to combat existing HPV, it can protect against other subtypes that the patient may not yet have been exposed.
The vaccine is made with live attenuated virus, so it is quite safe.However, as there are still no studies proving its safety in pregnancy, it is not indicated in this group.
Be sure to also see this short video, produced by MD.Saúde team, explaining simply the HPV vaccination.