Can HPV infection be prevented?

Recent advances in the study of the body's immunological response to HPV have led to the development of a vaccine against four common HPV types associated with the development of genital warts and cervical and anogenital cancers. This vaccine (Gardasil) has received FDA approval for use in women between 9 and 26 years of age and confers immunity against HPV types 6, 11, 16 and 18. Another vaccine directed at HPV types 16 and 18 is currently being tested, and initial trials with the vaccine have shown that the HPV-16/18 vaccine is safe and induces a high degree of protection against HPV-16/18 infection. These encouraging results suggest that widespread vaccination for HPV types could begin in the near future.

Abstinence from sexual activity can prevent the spread of HPVs that are transmitted via sexual contact, but a person who abstains from sex may still become infected with other HPV types, such as those that cause common skin warts. Some researchers have postulated that HPV infection might be transmitted from the mother to her infant in the birth canal, since some studies have identified genital HPV infection in populations of young children and cloistered nuns. Hand-genital and oral-genital transmission of HPV has also been documented and is another means of transmission.

HPV is transmitted by direct genital contact during sexual activity. The virus is not found in or spread by bodily fluids, and HPV is not found in blood or organs harvested for transplantation. Condom use seems to decrease the risk of transmission of HPV during sexual activity but does not completely prevent HPV infection. Spermicides and hormonal birth control methods cannot prevent the spread of HPV infection.

Testing for cervical HPV

The NHS has been considering HPV testing as part of the cervical cancer screening programme. It is not yet routinely available on the NHS. A trial called ARTISTIC is looking at whether testing for HPV as well as cervical screening works better than cervical screening alone. The researchers in Manchester have finished the trial and are looking at the results. They hope to have these by the end of 2008.

What should a person do if exposed to someone with genital warts?

Both people with HPV infection and their partners need to be counseled about the risk of spreading HPV and the appearance of the lesions. They should understand that the absence of lesions does not exclude the possibility of transmission and that condoms are not completely effective in preventing the spread of the infection. It is important to note that it is not known whether treatment decreases infectivity.

Finally, female partners of men with genital warts should be reminded of the importance of regular Pap smears to screen for cervical cancer and precancerous changes in the cervix, since precancerous changes can be treated and reduce a woman's risk of developing cervical cancer. Similarly, men should be informed of the potential risk of anal cancers, although it is not yet been determined how to optimally screen for or manage early anal cancer.

Wide Use of HPV Vaccines

Two vaccines against cervical cancer are being widely used without sufficient evidence about whether they are worth their high cost or even whether they will effectively stop women from getting the disease, two articles in this week’s New England Journal of Medicine conclude.
Both vaccines target the human papillomavirus, a common sexually transmitted virus that usually causes no symptoms and is cleared by the immune system, but which can in very rare cases become chronic and cause cervical cancer.

The two vaccines, Gardasil by Merck Sharp & Dohme and Cervarix by GlaxoSmithKline, target two strains of the virus that together cause an estimated 70 percent of cervical cancers. Gardasil also prevents infection with two other strains that cause some proportion of genital warts. Both vaccines have become quick best sellers since they were licensed two years ago in the United States and Europe, given to tens of millions of girls and women.

“Despite great expectations and promising results of clinical trials, we still lack sufficient evidence of an effective vaccine against cervical cancer,” Dr. Charlotte J. Haug, editor of The Journal of the Norwegian Medical Association, wrote in an editorial in Thursday’s issue of The New England Journal. “With so many essential questions still unanswered, there is good reason to be cautious.”

In her article, Dr. Haug points out the vaccines have been studied for a relatively short period — both were licensed in 2006 and have been studied in clinical trials for at most six and a half years. Researchers have not yet demonstrated how long the immunity will last, or whether eliminating some strains of cancer-causing virus will decrease the body’s natural immunity to other strains.

More to the point, because cervical cancer develops only after years of chronic infection with HPV, Dr. Haug said there was not yet absolute proof that protection against these two strains of the virus would ultimately reduce rates of cervical cancer — although in theory it should do so.
Dr. Richard Haupt, medical director of Merck, called these concerns “very theoretical,” noting that continuing research and monitoring suggested that immunity would be longlasting and that the vaccine would not lead to problems with other strains.

He added that cervical cancer was “just the tip of the iceberg” and that HPV caused a huge amount of expensive and stressful testing in developed nations that could be avoided with vaccination.

The vaccines, which require three shots for a complete series, cost about $400 to about $1,000, depending on the country and the fees for doctors’ visits. Unlike older vaccines that save money by preventing costly disease, these vaccines cost health systems money.

The second paper published this week, a study by Jane J. Kim and Dr. Sue Goldie of Harvard, looks at the issue of costs and concludes that the vaccines will be cost effective only if used in certain ways. In particular, the researchers say the vaccines will be worth the cost only if they prove to protect girls for a lifetime, and if current methods for screening for cervical cancer using Pap smears can be safely adjusted to reduce costs there. Further research is required in both areas.

“I believe the vaccine is a great advance, but we have to implement it properly to get the benefits, and that hasn’t happened,” said Dr. Philip Davies of the European Cervical Cancer Association.

In developed countries, Pap smear screening and treatment have effectively reduced cervical cancer death rates to very low levels already. There are 3,600 deaths annually from cervical cancer in the United States, 1,000 in France and 400 in Britain.

Cervical cancer, like skin cancer, can generally be caught at precancerous or non-invasive stages and treated. Because the vaccine prevents infection with only some of the cancer-causing strains, Pap smear screening must continue even in those who are vaccinated.

The Harvard study concluded that giving the vaccine to 12-year-olds would cost $43,600 for every “quality adjusted year of life” it saved by preventing a cancer death; that price would often be considered acceptable by health officials in wealthy countries, experts say.

Dr. Haupt said the study proved that it was best to vaccinate early. “It underscores the value of vaccinating pre-adolescent girls,” since the vaccine works fully only in girls who have not been exposed to HPV.

But if the vaccine were given to all girls and women up to age 21, the cost per year of life saved would be far higher — $120,400, the Harvard study concluded. And if the vaccines prove to require a booster shot, as many critics believe, that cost rises to $140,000. In such cases it might make more economic sense to rely on Pap smear screening alone, the researchers said.

How is HPV treated?

External genital warts

There is no cure or treatment that can eradicate HPV infection, so the only currently possible treatment is to remove the lesions caused by the virus. Unfortunately, even removal of the warts does not necessarily prevent the spread of the virus, and genital warts frequently recur. None of the available treatment options is ideal or clearly superior to others.

A treatment that can be administered by the patient is a 0.5% solution or gel of podofilox (Condylox). The medication is applied to the warts twice per day for 3 days followed by 4 days without treatment. Treatment should be continued up to 3-4 weeks or until the lesions are gone. Podofilox may also be applied every other day for a total of three weeks. Alternatively, a 5% cream of imiquimod [(Aldara) (a substance that stimulates the body's production of cytokines, chemicals that direct and strengthen the immune response)] is likewise applied by the patient three times a week at bedtime, and then washed off with mild soap and water 6-10 hours later. The applications are repeated for up to 16 weeks or until the lesions are gone.

Only an experienced physician can perform some of the treatments for genital warts. These include, for example, placing a small amount of a 10-25% solution of podophyllin resin on the lesions, and then, after a period of hours, washing off the podophyllin. The treatments are repeated weekly until the genital warts are gone. An 80-90% solution of trichloroacetic acid (TCA) or bichloracetic acid (BCA) can also be applied weekly by a physician to the lesions. Injection of 5-flurouracil epinephrine gel into the lesions has also been shown to be effective in treating genital warts.

Interferon alpha, a substance that stimulates the body's immune response, has also been used in the treatment of genital warts. Treatment regimens involve injections of interferon into the lesion every other day over a period of 8 to 12 weeks.

Alternative methods include cryotherapy (freezing the genital warts with liquid nitrogen) every 1 to 2 weeks, surgical removal of the lesions, or laser surgery. Laser surgery and surgical excision both require a local or general anesthetic, depending upon the extent of the lesions.

How are genital warts diagnosed?

Genital warts are fairly common; approximately 500,000 new cases of genital warts are diagnosed each year in the U.S. A typical appearance of a genital wart may prompt the physician to treat without further testing, especially in someone who has had prior outbreaks of genital warts. Genital warts usually appear as small, fleshy, raised bumps, but they sometimes can be extensive and have a cauliflower-like appearance. They may occur on any sexually-exposed area. Over 90% of genital warts are caused by HPV-6 and HPV-11, the so-called "low risk" HPV types.

What HPV is...

Human papilloma viruses are known as HPV. They can affect the skin and the moist membranes that line parts of the body, including

* The lining of the mouth and throat
* The cervix
* The anus

There are more than 100 different types (or ‘strains’) of human papilloma virus (HPV). Each type has a different number. HPV is common. About 3 out of 4 people (75%) have the virus at some time in their lives. For most people it causes no symptoms and goes away on its own. It is much more common in young people, probably because we develop immunity to the virus as we get older.Some types of HPV can cause changes in the cells of the cervix or the lining of the mouth and throat. They are known as high risk HPVs. Doctors call these changes in cells ‘dysplasia’. The changed cells have an increased risk of becoming cancerous.Other types of HPV can cause warts and verrucas. These types of HPV are sometimes called the ‘wart virus’ or ‘genital wart virus’ and they include types 6 and 11. Warts and verrucas are most common on the hands and feet, in the genital area and around the anus. But they can be on any part of the body. Types of HPV that cause warts and verrucas do not usually cause cell changes that may develop into cancer. They are called low risk HPVs.

HPV and cervical cancer

Some types of HPV can increase the risk of developing cervical cancer, particularly types 16, 18, 31, 33 and 45. They are called high risk types. Almost all women with cervical cancer have at least one of these types of HPV in the cells of their cervix.Of the different types of HPV, types 16 and 18 cause about 7 out of 10 (70%) cancers of the cervix. The other types cause most of the remaining 30% of cervical cancers. Do remember that most women with high risk HPV don’t develop cervical cancer. We know from research that other factors affect whether you develop a cancer, such as how well your immune system is working or whether you smoke. Women who smoke and have a high risk type of HPV infection are more likely to go on to get cervical cancer.Remember that regular cervical screening will pick up abnormal cervical cells before they become cancerous. So even if you have HPV and smoke, you can prevent cervical cancer if you go for screening when you are invited.People with low immunity also have an increased risk of cervical cancer. Your immunity may be low because you take certain medicines for another condition, or because you have an illness that affects your immunity, such as HIV AIDS. If you have low immunity, it is particularly important to have regular cervical screening.

How you get HPV

Types of HPV that affect the skin can be passed on by skin contact with an affected person. The types of HPV that affect the mouth and throat can be passed on through kissing.Genital HPV is usually spread through intimate, skin to skin, contact during sex.You can have the genital HPV virus for years and not have any sign of it. So it isn’t unusual to have a long term partner and then be told you have the virus after medical tests such as cervical screening. Many people then worry that their partner has been unfaithful, or will think they have been unfaithful. But finding out you have HPV doesn’t necessarily mean that you or your partner have been unfaithful. There is no way of knowing how long you have had the virus. It could be weeks, months or years.

HPV Virus in Men

Much of the information about HPV virus (human papillomavirus) centers on women, since having the virus increases their risk of getting cervical cancer. But HPV virus in men can cause health problems, too. So it's important for men to understand how to reduce the risks of HPV infection. It can increase a man's risk of getting genital cancers, although these cancers are not common. HPV can also cause genital warts in men, just as in women.More than half of men who are sexually active in the United States will have HPV at some time in their life. Often, a man will clear the virus on his own, with no health problems.

Risks of HPV Virus in Men

Some of the 30 or so types of HPV associated with genital cancers can lead to cancer of the anus or penis in men. Both of these cancer types are rare. In those with a healthy immune system, they are even rarer. About 1,530 men in the U.S. were diagnosed with cancer of the penis in 2006, according to American Cancer Society estimates. About 1,910 men got a diagnosis of anal cancer.The risk of anal cancer is about 17 times higher in sexually active gay and bisexual men than in men who have sex only with women. Men who have HIV (human immunodeficiency virus) are also at higher risk of getting this cancer.Other types of HPV virus rarely cause cancer in men, but they do cause genital warts. At a given point in time, about 1% of sexually active men in the U.S. will have genital warts.

Male HPV: The Symptoms

The types of high-risk HPV that can cause cancer rarely present any symptoms in men or in women. Genital warts are the first symptom you may see with low-risk HPV strains that cause warts but not cancer.

Tests for HPV Virus in Men

To diagnose genital warts in men, the doctor will visually check a man's genital area to see if warts are present. Some doctors will apply a vinegar solution to help identify warts that aren't raised and visible. But the test is not foolproof. Sometimes normal skin is mistakenly identified as a wart.There is no routine test for men to check for high-risk HPV strains that can cause cancer. However, some doctors are urging anal Pap tests for gay and bisexual men, who are at higher risk of anal cancer caused by HPV. In an anal Pap test, the doctor collects cells from the anus, and then has them checked for abnormalities in a lab.

Treatments for HPV

There is no treatment for asymptomatic HPV infection. Instead, doctors treat the health problems that are caused by the HPV virus.When genital warts appear, a variety of treatments can be used. The patient can apply prescription creams at home. Or a doctor can surgically remove or freeze off the warts.Early treatment of warts is discouraged by some doctors because genital warts can go away on their own. It can also take time for all warts to appear. So a person who treats warts as soon as they appear may need another treatment later on.Anal cancer can be treated with radiation, chemotherapy, and surgery. The specific treatments depend on the stage of cancer - how big the tumor is and how far the cancer has spread.

HPV Vaccine for Men?

The HPV vaccine Gardasil, approved for use in women in 2006, is not yet approved for men. Studies are still being done to determine if the vaccine works in males. Eventually, public health experts say, boys and men may be vaccinated.

How to Manage HPV in a Relationship

If a man's long-term sexual partner has HPV, chances are good HPV transmission has already occurred and he also has it. HPV in men may clear from the body more easily than in women. Women, in general, often clear the virus in two years or less.The HPV types associated with cervical cancer usually do not cause health problems for a heterosexual man having sex with an HPV-infected woman.If a partner has HPV, it does not necessarily mean they have had sex with someone else recently. The virus can lay dormant in the body for years without causing noticeable symptoms.

How to Prevent Transmission of HPV

Abstinence is the only sure way to prevent HPV transmission. Risk of transmission can be lowered if a person has sex only with one person who is not infected and who is monogamous.To lower the risk of HPV transmission, men can also limit the number of sex partners and pick partners who have had few or no partners in the past.Condoms can provide some protection against HPV transmission. But they aren't 100% effective, since HPV is transmitted primarily by skin-to-skin contact. The virus can still infect the skin uncovered by the condom.In a recent study of young women who had just become sexually active, those whose partners used a condom each time they had sex were 70% less likely to get an HPV infection than were women whose partners used a condom less than 5% of the time.