Pap Smear
Pap smears are generally done during a gynecological exam. Once the vagina has been spread using a device called a speculum, a small, sterile brush is used to gather cells from inside the cervical opening and a small spatula to obtain cells from the outside of the cervix. These cells are then put on a glass slide and examined under a microscope. A pap smear can identify abnormal cervical cells. Abnormal cervical cells indicate the possible presence of cervical cancer or a precancerous lesion (one that will eventually progress to cervical cancer).
HIV Test
An HIV test is usually done using blood, although other bodily fluids such as saliva or urine can be used. When a human is infected with HIV, the immune system creates antibodies (special proteins used to combat viruses such as HIV) that are designed to bind to HIV. These antibodies usually appear in the blood 2 weeks after an HIV infection. Most HIV tests have two parts: the initial test and the confirmation test. The initial test uses a chemical that will fluoresce (emit light) when these antibodies are present in the blood. The confirmation test is more sensitive. It involves separating all of the proteins in the blood and then using special proteins that are designed to specifically recognize antibodies to HIV. This test, while more accurate, also takes longer and is more expensive.
HIV and Pap Smears
The processes involved in a pap smear and an HIV test are completely different and, as a result, a pap smear does not test for HIV. However, an HIV infection can cause certain changes that will be detectable on a pap smear. HIV infection can cause a condition known as cervical dysplasia, in which the cells of the cervix grow abnormally. HIV infections can also increase the risk of developing pelvic inflammatory disease. Because both conditions cause abnormal cells to appear on a pap smear, an abnormal pap smear often causes a gynecologist to recommend other tests--which include HIV testing and a screen for STDs.
