Introduction
HPV is considered a sexually transmitted disease. According to the CDC, an estimated 20 million Americans are living with the disease, with more than 6 million new cases each year. The responsible agent is the human papillomavirus, which typically causes viral warts. This virus has also been strongly implicated in cases of cancer of the cervix, and other parts of the male and female genitals. According to the American Cancer Society, more than 11,000 new cases of cervical cancer will be diagnosed in 2009 and there will be more than 4,000 deaths.
Over 40 strains of HPV affect humans. Some strains, types 6 and 11, characteristically cause genital warts and these are considered low risk strains for cervical cancer. The strains most implicated for cervical cancer, types 16 and18, do not cause genital warts.
Diagnosis of HPV
The presence of warts, typically in the genital area and/or anus, is highly suggestive of HPV. The warts are fleshy, itchy growths on the skin in these areas. The warts are characteristic of HPV infections and a doctor would make a diagnosis solely based on finding these warts, in most cases. A history of sexual contact strengthens the diagnosis, particularly if there was no condom used.
Trichloroacetic acid applied to areas suspected to be infected with HPV causes them to turn white. This test could be used by the doctor as part of his examination when there is a high index of suspicion but no clearly visible lesions. It is used mainly during a pelvic examination.
In women, a Pap smear may be diagnostic of HPV. A Pap smear involves taking a scraping or brushing from the cervix to examine the cells for abnormal changes. Changes in the cells considered precancerous or outright cancerous are highly suggestive of HPV infection.
Sometimes, a Pap smear is inconclusive. It is then followed up with a search for HPV genetic material using the HPV DNA test. Some types of HPV, especially types 16 and 18, are considered high risks for cervical cancer, although they do not cause genital warts. The presence of mildly abnormal changes in the cells of a Pap smear requires a follow-up HPV DNA test.
Addendum
According to the NIH, every woman with viral warts should have a Pap smear to exclude HPV infection of the cervix or detect early changes in the cervix suggestive of cancer. This could be life-saving, as early detection is one of the best ways to prevent cancer mortality.
According to the American Congress of Obstetricians and Gynecologists, every woman over age 21, or three years after first sexual activity, whichever comes first, should have a Pap smear every year. Those over 30 years old who have had three consecutively negative Pap smears can have a Pap smear every three years. Among high risk groups such as those with HIV, the immunosuppressed and those with previous cancerous or precancerous lesions in the cervix, more frequent testing is recommended.
