HIV tests

The following laboratory tests performed during initial patient visits can be used to stage HIV disease and to assist in the selection of ARV drug regimens:

• HIV antibody testing (if prior documentation is not available or if HIV RNA is below the assay’s limit of detection);
• CD4 T lymphocyte cell count (CD4 count);
• Plasma HIV RNA (viral load);
• Complete blood count, chemistry profile, transaminase levels, blood urea nitrogen (BUN), and creatinine, urinalysis, and serologies for hepatitis A, B, and C viruses;
• Fasting blood glucose and serum lipids; and
• Genotypic resistance testing. For patients who have HIV RNA levels <500 to 1,000 copies/mL, viral amplification for resistance testing may not always be successful.

Three common types of HIV tests: 1) nucleic acid tests (NAT), 2) antigen/antibody tests, and 3) antibody tests. HIV tests are typically performed on blood or oral fluid. They may also be performed on urine.  Each test has a window of latency before which results are undetectable.

• Nucleic acid test (NAT) can verify the presence HIV in the blood and can quantify the HIV viral load. HIV RNA  is usually detectable 10 to 33 days after an exposure. The lab may require several days to return results.
• HIV antigen/antibody test performed by a laboratory on blood from a vein can usually detect HIV infection 18 to 45 days after an exposure. Antigen/ antibody tests done with blood from a finger prick can take longer to detect HIV (18 to 90 days after an exposure).
  • The rapid antigen/antibody test is done with a finger prick and takes 30 minutes or less.
• HIV Antibody tests can take 23 to 90 days to detect HIV infection after an exposure. Most rapid tests and self-tests are antibody tests. In general, antibody tests that use blood from a vein can detect HIV sooner after infection than tests done with blood from a finger prick or with oral fluid .
  • With a rapid antibody screening test, usually done with blood from a finger prick or with oral fluid, results are ready in 30 minutes or less (Types of HIV Tests N.D.).
  • The oral fluid antibody self-test provides results within 20 minutes.

Legal considerations that may pose barriers to engaging care and seeking testing

Three examples of informed consent listed below demonstrate a wide variance among states' requirements.

• Click here to view your State Laws that address High-Impact HIV Prevention Efforts ️(➤ CDC).
  • 2020 Florida Statutes: Title XXIX. Chapter 381.004 HIV testing.
    • In a health care setting, the person to be tested shall be notified orally or in writing that the test is planned and that he or she has the right to decline the test. If the person to be tested declines the test, such decision shall be documented in the medical record. A person who has signed a general consent form for medical care is not required to sign or otherwise provide a separate consent for an HIV test during the period in which the general consent form is in effect.
  • 2019 California: Voluntary testing with oral or written informed consent regarding
    • information about the planned test
    • treatment options
    • importance of follow-up testing
    • right to decline testing
  • Lousiana RS 40:1171.3: Consent for HIV testing shall be incorporated into the patient's general informed consent for medical care on the same basis as are other screening or diagnostic tests; unless the patient declines or "opts out" of the testing. A separate consent form for HIV testing shall not be necessary.
• As of 2020, 37 states have laws that criminalize HIV exposure.
• In 21 states, laws require people with HIV who are aware of their status to disclose their status to sex partners.

References

State HIV Laws. N.D. Centers for Disease Control and Prevention [Reviewed August 28, 2020] Retrieved on 4/24/2021 from https://www.cdc.gov/hiv/policies/law/states/index.html

Types of HIV Tests. N.D. Centers for Disease Control and Prevention [Reviewed April 9, 2021] Retrieved on 4/18/2021 from https://www.cdc.gov/hiv/basics/hiv-testing/test-types.html