HPV (human papillomavirus)

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HPV : Background HPV : Treatment
HPV : Risk Factors HPV : Prevention
HPV : Signs and Symptoms HPV : Challenges
HPV : Complications HPV : References
HPV : Diagnosis

Background

HPV (human papillomavirus)HPV (human papillomavirus) is the most common sexually transmitted infection in the United States, despite the fact that it is largely preventable. About 14.1 million new cases of HPV occur in the U.S. each year, according to an analysis published by the Centers for Disease Control (CDC) in February 2013. Approximately 49% of new cases are reported in the age group 15-24.

HPV occurs more frequently than all other sexually transmitted infections combined (chlamydia, trichomoniasis, gonorrhea, HSV-2, syphilis, HIV and hepatitis B). Nearly 80% of all sexually active men and women will be infected at some point in their lives. Some can be repeatedly infected.

A person can become infected with HPV by having vaginal, oral, or anal sex with an infected partner. However, actual vaginal or anal penetration is not necessary to acquire this virus. Skin-to-skin genital contact, including sexual foreplay, can also transmit this disease. The virus enters the body through small breaks in the skin surface or in the mucous membranes lining the genitals.

There are over 100 types of HPV viruses that affect different parts of the body. Each virus is given a number or type. Approximately 40 of the viruses are sexually transmitted. At least 13 are cancer-causing (also known as high risk type). HPV 16 and HPV 18 subtypes 16 have been most closely associated with high-grade dysplasia and cancer.

Risk Factors

Both men and women are susceptible to the disease. According to most studies, men and women are at equal risk of being infected, and there are no differences among races and ethnic groups.

HPV is not necessarily related to promiscuity, although sexually active individuals who have multiple partners are certainly more susceptible. The risk of anal cancer caused by HPV is 17 to 31 times higher among gay and bisexual men than among heterosexual men.

People with HIV or other diseases that weaken the immune system are at greater risk of becoming infected with HPV and may develop more severe health problems as a result of the infection. Chemotherapy and immune-suppressing drugs (for transplants or auto-immune diseases) are also risk factors.

Signs and Symptoms

Most infected men and women do not experience any symptoms. Some types of HPV may cause genital warts which appear as whitish, grayish, or pinkish bumps around the anus or on the genitals. They are usually small, can be raised or flat, and are often cauliflower-shaped. The warts generally appear within a few weeks or a few months of exposure. They may spread to other nearby parts of the body. When oral sex has occurred, warts may appear in the mouth.

In addition to the visible warts, other symptoms of HPV infection may include a bad smell, burning, itching, or redness of the vulva or vagina, painful sexual intercourse, increased vaginal discharge, and bleeding (usually due to injury to warts during sex). These symptoms may appear without the warts, and the warts may appear without other symptoms.

Complications

The two strains of HPV that typically cause genital warts are HPV 6 and HPV 11. These are considered low-risk strains and rarely lead to cancer or other complications. However, other strains of HPV can produce much more severe problems.

Some strains of the HPV virus, including HPV 16 and HPV 18,can cause can cause lesions or cellular changes in the tissues of the female cervix (a condition called cervical dysplasia). Severe abnormalities may require colposcopy treatment, which involves surgically removing part of the cervix. Changes in the cervix can increase the risk of preterm delivery if an infected woman becomes pregnant. In addition, HPV infections can be transmitted to the respiratory tract of a baby during childbirth.

Persistent or untreated dysplasia can lead to cervical cancer. Cervical cancer is the fourth most common cancer and the fourth leading cause of cancer deaths among women around the world. Nearly all cases are attributable to HPV infection. Other less common cancers associated with untreated HPV are cancers of the throat, vulva, vagina, and anus.

Cancer often takes years to develop after infection. Symptoms of cervical cancer tend to appear only after the cancer has reached an advanced stage and may include vaginal bleeding, unusual or foul-smelling vaginal discharge, pelvic pain, pain after sexual intercourse, fatigue, weight loss, and a single swollen leg. In men, symptoms of anal cancer may include bleeding, pain, or a discharge from the anus, or changes in bowel habits. Early signs of cancer of the penis may include thickening of the skin, tissue growths, or sores.

Diagnosis

There are no blood, urine, or imaging tests for HPV. Your healthcare provider will ask about your symptoms and examine your genital area. He may use an instrument called a colposcope that shines a light and magnifies the view of the cervix. Often he will apply a vinegar solution to the skin to make it easier to see infected areas. The solution will turn white if HPV is present. Your healthcare provider may also do a biopsy, removing a tissue sample for laboratory tests.

Often HPV is discovered when a woman has a Papanikolaou test or Pap smear. Pap smears involve the gentle scraping of cells from the surface of the cervix and vagina. The cells are viewed under a microscope to determine if they are abnormal.

A DNA test may also be performed to detect the specific types of HPV connected to cervical cancer (primarily HPV 16 and 18). The sample used for this test is usually obtained at the same time as a Pap smear.

Treatment

For men and women with normally functioning immune systems, HPV infections are generally short-lived and are cleared from the body within two years. The younger the person at the time of infection, the quicker their infection will clear. Even women with mild pap smear abnormalities will spontaneously revert to normal in approximately 90% of cases.

Patients with genital warts can be successfully treated with various medical or surgical techniques. Some cases can be treated at home with a prescription cream called Podofilox. Other treatments are administered in an office setting and include caustic agents (Podophyllin and trichloracetic acid), cryotherapy (freezing of warts with liquid nitrogen), laser surgery (using a high intensity light beam to destroy the infection), and electrocauterization (using an electric current to burn off the infection). Over-the counter-preparations designed to remove common or flat warts should not be used.

Low-grade precancerous changes in the tissue of the female cervix are not usually treated directly because most of them will eventually go away on their own without developing into cancer. However, the patient should have follow-up Pap smears to ensure that the tissues are returning to normal. High-risk precancerous lesions are removed, usually by surgery, cryotherapy, electrocauterization, or laser surgery.

Treatments for cervical cancer depend on the stage of disease at the time of diagnosis. (The stage of disease is based on size, depth of invasion, and how far the cancer has spread.) Treatments may include chemotherapy, radiation therapy, or a full hysterectomy. Often a combination of treatments is used.

Prevention

Because HPV is transmitted during sexual activity, the most reliable way to prevent infection is to abstain from oral, vaginal, and anal sex or to have a mutually monogamous relationship with an uninfected sex partner. Condoms are of limited usefulness, since the HPV virus can be easily spread during foreplay without penile penetration.

In 2006, a vaccine called Gardasil was approved by the Food and Drug Administration (FDA). Gardasil protects against four strains of HPV (type 6, 11, 16 and 18) that together cause 70% of cervical cancers and 90% of genital warts The vaccine is most effective when given to children before they become sexually active. Children as young as 9 years of age can get vaccinated. The vaccine is given as a series of three shots over a six-month period. Although marketed primarily for women, Gardasil is also licensed for use in males (to protect their female partners and for prevention of genital warts). If the patient is already infected with HPV, the vaccine does not treat or cure that strain, but it can still help protect against other types of HPV.

A second vaccine, Cervarix, was approved in Europe, Australia, and the Philippines in 2007, and in the United States in 2009. Cervarix protects against two strains of HPV (types 16 and 18) that can cause cervical cancers. It does not protect against genital warts.

Regular Pap smears are the best protection against cervical cancer. Pap smears are recommended for all women who are 21 years of age or who have been sexually active for 3 years – whichever occurs first. Modern pap smears are both painless and accurate. Cervical cancer is almost always preventable or curable if cellular changes are detected and treated early, before cancer develops. Since the Pap smear was first developed over 50 years ago, there has been a steep decline in the number of women afflicted with invasive cervical cancer.

Challenges

When the HPV vaccines Gardasil and Cervarix first came onto the market, health officials dreamed of halting the spread of HPV. However, despite the widespread availability of effective vaccines, the vaccination rates have remained stagnant. Why are more people not getting vaccinated? And why are we still seeing patients with advanced and incurable cervical cancers? Probably the greatest hurdles are cost, concern about side effects, and compliance.

According to the American Cancer Society, the drug company price for both Gardasil and Cervarix is approximately $140. This does not include the office visit charge. So it is possible that the total cost of the three-shot series could be $500 or more. The adoption of the federal Affordable Care Act (ACA), which requires all new private insurance plans to cover HPV vaccines as well as Pap tests without consumer cost-sharing, may alleviate some of the cost concerns in the future.

Concern about vaccine safety is always an issue, especially with children. Both drugs are generally safe, but side effects do exist. Most of the side effects are local in nature, including inflammation and pain at the injection site. A small amount of patients experience infection or an allergic reaction to the vaccine. Also, Gardasil has been associated with a higher proportion of fainting than with other vaccines, so it is often advised that patients remain seated for 15 minutes after vaccination. There has been a recent public scare about vaccines in general — including a false report linking the measles vaccine to autism – which has also contributed to the concern.

Like any drug that is not taken in a single dose or a daily dose, compliance is always an issue. Since the vaccine is administered in a three-shot series over a 6 month period, completing the entire course of treatment can be difficult. Many girls who start the treatment regimen fail to get all 3 shots, and thus are less likely to be protected.

In addition, some parents believe that the vaccination might give preteens a false sense of security and lead to greater promiscuity. However, a study published in the journal Pediatrics (conducted by researchers at Kaiser Permanente Center for Health Research and Emory University) showed that girls who receive the HPV vaccination are no more likely to engage in sexually risky behaviors than girls who are not vaccinated. The behaviors monitored included getting pregnant, developing sexually transmitted diseases, and seeking birth-control counseling.

No matter what position a person takes on the issue of HPV vaccinations, it is undeniable that HPV and cervical cancer are still problems. Perhaps some of the challenges can be overcome with better education among women, more persuasive prevention campaigns, and healthcare reforms. There is definitely hope that cervical cancer will be irrelevant within the next few decades.

References:

1) Genital HPV Infection – Fact Sheet
Source: Centers for Disease Control and Prevention

2) Incidence, Prevalence, and Cost of Sexually Transmitted Infections in the United States – CDC Fact Sheet
Source: Centers for Disease Control and Prevention

3) Human papillomavirus (HPV) and cervical cancer
Source: World Health Organization

4) Human Papillomavirus and Genital Warts Fact Sheet
Source: Office on Women’s Health U.S. Department of Health and Human Services

5) Human Papilloma Virus
Source: Aetna InteliHealth

6) General Information About Cervical Cancer
Source: National Cancer Institute

7) Sexually Transmitted Diseases
Source: The Center for Menstrual Disorders and Reproductive Choice

8) Preventive services covered by private health plans under the ACA
Source: The Henry J Kaiser Family Foundation

9) HPV and Cancer Fact Sheet
Source: National Cancer Institute

10) HPV Vaccine Doesn’t Lead To Promiscuous Tweens
Source: Time Inc.

Posted in STI.