Can a Pap smear detect HIV?

A Pap smear screens for cervical cancer by looking for abnormalities in the cells of a woman’s cervix. Since its introduction in the United States in 1941, the Pap smear, or Pap test, is credited with dramatically reducing the rate of death due to cervical cancer.

While cervical cancer can be fatal if left untreated, the cancer typically grows slowly. The Pap smear detects changes in the cervix early enough for effective intervention.

Guidelines recommend that women ages 21 to 65 receive a Pap smear every three years. The guidelines allow for a Pap smear every five years for women ages 30 to 65 if they’re also screened for human papillomavirus (HPV). HPV is the virus that can cause cervical cancer.

A Pap smear is often performed at the same time as tests for other sexually transmitted infections (STIs), such as HIV. However, a Pap smear doesn’t test for HIV.

If a Pap smear shows the presence of abnormal cells on the cervix, the healthcare provider may recommend a colposcopy.

A colposcope uses low magnification to illuminate abnormalities of the cervix and surrounding area. At that time, the healthcare provider also may take a biopsy, which is a small piece of tissue, for laboratory examination.

In recent years, it’s become possible to test for the presence of HPV DNA directly. Collecting a tissue sample for DNA testing is similar to the process of taking a Pap smear and may be done at the same visit.

Everyone between ages 13 and 64 should get an HIV test at least once, according to the Centers for Disease Control.

At-home testing can be used to screen for HIV, or the test can be performed at a healthcare provider’s office. Even if someone gets tested for STIs annually, they can’t assume that any specific test, including a test for HIV, is part of a routine screen.

Anyone who wants an HIV screening should voice their concerns to their healthcare provider. This can spark a discussion about what STI screenings should be performed and when. The right screening schedule depends on a person’s health, behaviors, age, among other factors.

If an HIV screening takes place at a healthcare provider’s office, one of three lab tests are likely to be performed:

  • an antibody test, which uses blood or saliva to detect proteins formed by the immune system in response to HIV
  • an antibody and antigen test, which checks the blood for proteins associated with HIV
  • an RNA test, which checks the blood for any genetic material associated with the virus

Recently developed rapid tests don’t require the results to be analyzed in a lab. The tests look for antibodies and can return results within 30 minutes or less.

The initial test likely will be an antibody or antibody/antigen test. Blood tests can detect a lower level of antibody than found in saliva samples. This means that blood tests can detect HIV sooner.

If a person tests positive for HIV, follow-up testing will be done to determine if they have HIV-1 or HIV-2. Healthcare providers usually determine this using an immunoblot test.

The U.S. Food and Drug Administration (FDA) has approved two home HIV screening tests. They are the Home Access HIV-1 Test System and the OraQuick In-Home HIV Test.

With the Home Access HIV-1 Test System, a person takes a pinprick of their blood and sends it off to a lab for testing. They can call the lab in a day or two to receive the results. Positive results are routinely retested to ensure that the result is accurate.

This test is less sensitive than one that uses blood from a vein, but it’s more sensitive than one using a mouth swab.

The OraQuick In-Home HIV Test uses a swab of saliva from the mouth. Results are available in 20 minutes. If a person tests positive, they’ll be referred to testing sites for a follow-up test to ensure accuracy. Learn more about home tests for HIV.

Getting tested early is the key to effective treatment.

“We recommend everyone get an HIV test at least once in their lives,” says Michelle Cespedes, MD, a member of the HIV Medicine Association and an associate professor of medicine at the Icahn School of Medicine at Mount Sinai.

“The result of that is that we pick up people before their immune systems are ravaged,” she says. “We get them on treatment sooner rather than later to prevent them from ever being immunocompromised.”

People with known risk factors for HIV should assess their options. They can either schedule an appointment with their healthcare provider for lab testing or purchase an at-home test.

If they choose to do at-home testing and they have a positive result, they can ask their healthcare provider to confirm this result. From there, the two can work together to assess the options and determine next steps.