What is HPV?
HPV is short for human papillomavirus. The human papillomavirus’ are a family of more than 100 viral types over 40 of which can infect mucosal surfaces such as the female genital tract. It is now known that persistent infection with one of the high risk types of the human papillomavirus is a necessary cause of cervical cancer in women. It is responsible for external genital warts as well as a large percentage of vaginal and vulvar cancers. The most commonly used test called the hybrid capture 2 test detects 13 intermediate and high risk types of the human papillomavirus. The hybrid capture test is done by collecting a sample of cells from the cervix or vagina with a brush similar to that used in taking a Pap test. In fact, if a liquid based Pap test is done an HPV test can be done from the same sample.
What do the results of the hybrid capture test indicate?
The results of the hybrid capture test indicates whether the cells collected demonstrate the presence of one of 13 intermediate and high risk viral types of the human papillomavirus. The presence of a positive HPV test is a powerful indicator of risk. If a woman has an atypical Pap smear (so-called ASCUS) and her HPV test is negative, that atypical Pap test is equal to a negative Pap test. However, if the HPV test is positive in the presence of an atypical Pap test that indicates true risk, therefore, a colposcopy exam should be done to rule out high grade precancerous changes or rarely a true cancer. If a Pap test were to come back low grade, high grade, or cancer, an HPV test is generally not done since almost everyone having Pap tests demonstrating the above abnormalities, would be positive for HPV.
What follow-up is needed based on the results of the hybrid capture test?
Usually the hybrid capture test is not done in women under the age of 30 unless they have first demonstrated an atypical Pap smear. The reason for this is that in young sexually active women with multiple partners, the HPV test will frequently be positive but not be indicative of persistent infection. The reason for this is that once infected with one of the types of human papillomavirus, 90% of women will clear the viral infection. It is the 10% who do not clear the infection who are at risk for high grade precancer and cancerous changes. It has been determined that due to a higher percentage of women over the age of 30 who are in stable relationships, that an HPV test in a woman over the age of 30 is less likely to be positive. If it is positive, it is more likely to be indicative of a persistent infection.
Anyone who has a Pap test that comes back low grade, high grade, or cancer should be examined with a colposcope. Anyone who has an atypical Pap test and a positive HPV test should be examined with a colposcope. Anyone with an atypical Pap test and a negative HPV test should have a repeat Pap test and HPV test in one year. If both the Pap test and the HPV test are negative, we recommend a repeat Pap test within two years if under the age of 30 and three years over the age of 30. In women under the age of 30 who have not had HPV tests done, the Pap smear should be done on an annual basis.
