A cervical Pap smear, performed during a gynaecological exam, involves the gathering of cells from inside a woman's cervix, which a lab then will test for any abnormalities. While this test can detect cervical cancer and precancerous lesions, the test alone cannot detect the presence of HIV. Anal Pap smears, usually performed on men who have sex with men, also are becoming more routine to check for anal cancer, but similarly don't test specifically for HIV.
Most tests for the human immunodeficiency virus (HIV) screen blood samples. Antibodies against the virus form and appear in the blood starting about weeks after initial infection with the virus. A blood sample is one of the cleanest, most reliable ways to determine if a person is HIV-positive or not. The saliva-based OraSure test also is an accurate way to discover a person's HIV status.
Pap Smears and HIV
Since cervical Pap smears test for cell abnormalities in the cervix by collecting cells, and HIV tests use blood or saliva to determine a person's status, it is not possible for the former test to determine the latter test's conclusion. That being said, the Centers for Disease Control and Prevention notes that there are certain indicators that could mean a woman has HIV that may show up on a Pap smear: HIV infection can cause cervical dysplasia, or abnormal growth of cervical cells; the development of pelvic inflammatory disease also can occur due to HIV. The CDC also reports that abnormal Pap smears can be associated with low CD4 cell, or T cell, counts found in HIV-positive women. However, as these conditions also can occur in women who are HIV-negative, only an HIV test can indicate if HIV is present and increasing a woman's risk for other infections.
While most men receiving anal Pap smears are men having sex with men who already know they are HIV-positive, it is possible that anal warts or anal cancer will show up during a Pap smear before HIV status is known.
According to the CDC, "HIV+ women are 10 times more likely to have abnormal Pap smears than HIV-negative women." This being the case, a gynaecologist or other doctor who detects a potentially HIV-related infection on a cervical or anal Pap smear should recommend an HIV test to her patient, as well as tests that screen for other sexually transmitted diseases.