Human papilloma virus

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 3, 2016
StartDiseasesHuman papilloma virus

Human papilloma virus or HPV is the most common sexually transmitted disease (STD) in America. It spreads by means of oral sex, anal sex, or vaginal sex even when the carrier displays no signs or symptoms. Symptoms may not appear until years after the sexual contact with the carrier making some case origins very difficult to track.

Contents

Definition & Facts

HPV is part of the papillomaviridae family of viruses, and there are over 100 different strains of HPV, more than 30 of which pass from one person to another through sexual contact. Most genital HPV infections run their course over a few years; however, others may persist for many years with or without cellular abnormalities.

Many HPVs produce warts mostly innocuous and of no more than cosmetic concern. Two HPV types, however, HPV-6 and HPV-11, cause the majority of cases of genital warts (called condylomata acuminatum) that may appear within several weeks after the sexual contact, months or years later, or never at all. HPVs also cause flat, abnormal growths in the genital area and on the cervix.

Symptoms & Complaints

In most cases, the immune system contains and then repels HPV infections before they can implant warts. When warts appear, they can be flat, raised, or shaped like cauliflower. Sometimes there is a single wart while other times there can be many warts - both large or small, on the anus, groin, penis, scrotum, or thigh. Warts vary in appearance depending on the HPV variety:

  • Genital warts may be flat lesions, small bumps, or stem-like protrusions. In females, genital warts appear mostly on the vulva but also around the anus, on the cervix, or in the vaginal canal.
  • In males, there may be genital warts on the penis or the scrotum or near the anus. They may itch but usually cause no discomfort or pain.
  • Plantar warts are hard growths usually on the feet, where they may be uncomfortable or painful.
  • Flat warts are slightly raised lesions darker than skin color usually on the face, the neck, or areas scratched to relieve itching. These HPV infections usually affect young patients.

Two specific HPV strains, 16 and 18, cause most cases of cervical cancer. These two usually don't cause warts, so patients often aren't aware of their infections. The longer the virus is in the body, the higher the risk of cervical or anal cancer. It lives in mucous membranes in the genital area or on the skin. In early stages, cervical cancer usually shows no signs or symptoms. For this reason, it's important to have regular cervical examinations or Pap tests (also called Pap smears) for tissue changes that may precede cancer.

Causes

Patients contract genital HPV infections through vaginal and anal intercourse and openings in the outer layer of the skin in the genital region. Some oral or upper respiratory tract HPV lesions come from oral sex. An infected mother may transmit the virus during labor and delivery to her infant's genitals or upper respiratory tract. Other risk factors for common HPV infections:

  • Number of sexual partners: the greater the number, the more likelihood of an HPV genital infection. Sex with a promiscuous partner also increases the risk.
  • Age: plantar and genital warts are more likely on adolescents and young adults.
  • A weakened immune system can trigger HPV infections. Immunosuppressive drugs can weaken immune systems after organ transplants.
  • Skin: cut, abraded, torn, or punctured skin offers the virus easy entry into the body.
  • Nonsexual physical contact. Touching warts or surfaces exposed to HPV as in public swimming pools may increase the risk of infection.

Diagnosis & Tests

A visual examination of genital warts is one way to diagnose HPV infections. Women who may be infected by HPV that causes cancer first must find out whether their Pap smear results are abnormal. Such a screening is the main way physicians find precancerous abnormalities in the cervix.

During a Pap smear, a doctor takes a swab of cells from the cervix. If abnormal cells are found, physicians may decide on more testing, often a colposcopy, in which a magnifying device examines the vulva, vagina, and cervix after application of an acetic acid solution. If abnormalities are detected, tissue biopsies of abnormal areas may be taken. If the biopsy shows dysplasia or actual cancer, treatment follows.

Women in their 20s should have exams every three years. Women aged 30 to 65 should continue at the same three-year intervals or at every five years with HPV deoxyribonucleic acid (DNA) tests on the same occasions. A DNA test can tell whether any HPV virus detected is cancerous. It is typically for patients whose cervical screening show abnormalities. Women 65 and older can discontinue after three consecutive normal exam results or two cervical exams with HPV DNA tests and normal results.

Treatment & Therapy

There is no single curative, silver-bullet treatment for condylomata acuminata. Eradication of symptoms is the purpose of treating warts and squamous intraepithelial lesions. The treatment plan is to eradicate as many lesions as possible until the patient's immune system suppresses further viral replication. However, warts may recur after treatment from activation of latent virus without reinfection.

Standard practice can remove most genital warts, but no single treatment or modality is ideal for all warts. Factors that influence HPV treatment are the size, shape, number, and sites of lesions, possible adverse effects, patient preferences, and previous treatment. Surgical excision, chemical ablation, and cryotherapy are usual treatment options. Recurrence rates are high.

Prevention & Prophylaxis

In 2006, the United States Food and Drug Administration approved for HPV types 6, 11, 16, and 18 a vaccine with a 90-percent rate of efficacy in infection prevention. Two clinical trials of therapeutic vaccination have demonstrated either complete or partial responses in patients with vulvar or vaginal dysplasia.

There are now several HPV vaccines licensed in the USA for prevention of infections from HPVs 6, 11, 16, 18, 31, 33, 45, 52, and 58. Administration of all HPV vaccines involves a three-dose series of intramuscular injections over six months. In addition to vaccination, practicing safe sex including correct condom use can help prevent HPV infection.