Things That Affect HIV Tests
Reasons you may not be able to have the test or why the results may not be helpful include:
- Using corticosteroids.
- Antibody testing during the seroconversion period.
- Having an autoimmune disease, leukemia, or syphilis.
- Drinking too much alcohol.
What To Think About
READ: Sex & HIV: What To Say Before You Play
Follow Up. After initial testing, it is important for your doctor to contact you with the results of your test. Be sure to tell your doctor how and where to contact you. If your doctor has not contacted you within 1 to 2 weeks of your test, call and ask for your results.
False Positives. The ELISA is a good screening test, because it is usually positive when an HIV infection is present. But the ELISA test results can indicate HIV is present when it is not (false-positive). So the ELISA alone cannot be used to make a definite diagnosis of HIV infection. No one is considered HIV-positive until he or she has a positive Western blot, IFA, or PCR test.
Infants. Detecting HIV in a newborn infant is difficult. Until about 18 months of age, even a baby who is not infected may still have HIV antibodies received from his or her HIV-positive mother. A PCR test may be done to see if HIV genetic material (RNA or DNA) is present in the baby.
Time. To be certain that an HIV infection is not present, a person must test negative for the virus at least 6 months after the last possible exposure to HIV. Testing is often done at 6 weeks, 3 months, and 6 months to find out whether a person is infected.
Home Kits. Home blood test kits to detect an HIV infection are available without a prescription at pharmacies or through mail order. These kits provide instructions and materials for collecting a blood sample that is then sent to a lab for analysis. Results are available over the phone using an anonymous code number. Counseling is also available over the phone for people who use the test kit. Rapid test kits are also available and results are received within a half-hour, compared to 1 to 2 weeks with conventional testing. Positive rapid HIV test results need to be confirmed by a Western blot test.
Alternate Tests. A screening test for HIV infection may also be done on urine or saliva. An oral HIV test finds antibodies to HIV. Urine testing is rarely done. Oral test kits that find HIV-1 and HIV-2 in saliva have been approved by the United States Food and Drug Administration (FDA). The test results are provided the same day. Test results that show an HIV infection need to be confirmed by a Western blot test.
The Law. Most states require health professionals, clinics, and hospitals to report confirmed cases of HIV infection to the state health department. Some states allow anonymous reporting (the person’s name or other identifying information is not provided). Other states require confidential reporting (identifying information is provided but only to authorized public health officials). All states must report the numbers of cases of AIDS, without names or other identifying information, to the Centers for Disease Control and Prevention (CDC).
Communicate. If you have a positive test result, contact your sex partners to inform them. They may want to be tested. You may be able to get help from your local health department to do this.
HIV+. After an HIV infection is present, other tests are done to determine when to treat the infection and how treatment is working. These tests include a CD4+ count and the viral load. For more information, see the topics CD4+ Count and Viral Load Measurement.
Two types of HIV have been identified.