HIV Testing

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What Is HIV Testing?

Human immunodeficiency virus (HIV) is the virus that causes acquired immune deficiency syndrome (AIDS). HIV destroys the body's immune system and eventually leads to AIDS. People with AIDS develop many diseases and "opportunistic" infections (such as pneumonia, tuberculosis, cancer, and skin infections) that may ultimately lead to death. Prevention is critical. There is no cure for HIV/AIDS, but currently, there are effective treatments that can drastically slow the disease process and prevent illness and HIV transmission. If you have been exposed to the HIV virus in any number of ways, you can very easily be tested to determine whether or not you have been infected with the virus.

  • How HIV is transmitted
    • The HIV virus can be transmitted by unprotected sexual contact (vaginal, anal, or oral sex), sharing needles, by transfused blood products, from mother to newborn, and by occupational needle-stick exposures.
      • Higher risk of HIV transmission is associated with penile anal intercourse and sharing needles to inject drugs.
      • Higher risk of HIV transmission is associated with a higher number of sexual partners.

Soon after the HIV virus enters the body, it begins replicating at a rate of 10 billion new viral particles per day. In fact, it is during this early burst of viral replication, within the first month of contracting HIV, when many patients are asymptomatic (not showing symptoms), that the virus is high in numbers and more likely to be spread from one person to another.

  • Globally, most new HIV infections occur in developing countries, such as in Africa and Asia, where the vast majority of cases are transmitted by sexual relations between men and women (heterosexual intercourse).
  • In the United States, the majority of cases are known to have been transmitted by homosexual and bisexual men. Among homosexuals, it appears that the receptive partner during anal intercourse is placed at highest risk for becoming infected.
  • Most women acquire HIV through heterosexual contact.
    • In the U.S., the incidence of HIV is approximately three times greater in males than in women.
    • Among heterosexuals, male-to-female transmission is much more likely to occur than female-to-male transmission.
    • The incidence of HIV transmission is lower in circumcised males.
    • The presence of other sexually transmitted diseases such as herpes and syphilis can facilitate the transmission of HIV.
    • The incidence of HIV transmission is seven times higher in African Americans as compared to Caucasians.

Why Is HIV Testing Performed?

  • The main reason to perform an HIV test is to find out if someone is infected with the HIV virus so they can benefit from treatment. Most people with HIV have no symptoms or signs.
  • In the U.S., HIV testing is recommended for all people ages 13-64 in all health care settings regardless of risk factors.
  • HIV testing is often done as part of routine testing for general medical care.
  • In many medical settings, HIV testing is offered on an opt out basis. That is, the HIV test is performed unless a person specifically requests that it not be done. People are always informed that HIV testing is planned, and consent to be tested may be part of the general consent to receive medical care.
  • When a person is identified as HIV-positive, they can be treated with medications. These medications greatly extend lives and improve health as well as prevent HIV from being transmitted to others.
  • HIV testing is performed during pregnancy to identify HIV-positive pregnant women. Treatment for HIV during pregnancy dramatically decreases the chances that the baby will contract HIV.
  • Babies born to women who are HIV-positive are tested to be sure that they have not become HIV-infected.
  • Donated blood, blood products, and people who donate organs are tested for HIV to be sure that the virus is not spread by blood and organ donations.
  • The HIV test does not test for AIDS. Once a person is found to be HIV-positive, further testing is needed to determine if the infection has causes severe damage to their immune system which is known as AIDS.

Free HIV Testing and Benefits

Guidelines from the U.S. Centers for Disease Control and Prevention (CDC) recommend HIV testing in all patients 13 years and older regardless of risk factors.

The life expectancy of a person infected with HIV undergoing treatment with anti-retroviral medication has greatly increased over the past 10 years.

Life expectancy varies widely with subpopulations. Given early treatment with highly active antiretroviral therapy (HAART) and a compliant patient, life expectancy in 2017 is the same for those without HIV infection.

  • There are many reasons to have an HIV test performed:
    • To know about HIV so that you do not transmit the virus to others, including sexual partners and future children and early treatment greatly reduces the chance of transmission
    • By reducing the "viral load" or number of viruses circulating in the blood, medical treatment of HIV-positive mothers with antiretroviral medication during pregnancy has been shown to reduce the chances of transmission of HIV from mother to child by a factor of 10.
    • To take advantage of early treatment and monitoring
    • Now antiretroviral therapy is being started earlier as newer medications have developed that have fewer side effects and are better tolerated than previously, which equates to a longer life span.
    • Early treatment can slow the growth of HIV and prevent or reverse AIDS.
    • Anonymous HIV testing is available in most states. Often, the tests are funded by the public health department and are performed at no cost. Anonymous testing means that absolutely no one, except you, has access to your test results because your name is never recorded at the test site.
      • You will be given a letter and number code that will be matched with the test results.
      • Most anonymous test sites provide pretest counseling and risk assessment.
      • You must return, in person, to get your results.
      • Anonymous testing sites never give written results and are discouraged to do so because there is no way to contact a person who tests positive and make sure they are linked to HIV care.
      • Anonymous HIV antibody testing may not be an option in several circumstances.
        • Active military personnel and all men and women seeking to join the armed services are required to participate in biennial HIV testing. Testing positive for HIV disqualifies an applicant from joining the service.
        • Some anonymous testing sites will not perform an antibody test on children under the age of 12. Children under 12 have to be tested through a private physician or clinic where the results will be confidential -- not anonymous.
    • If you give your name at an HIV test site, the test is considered confidential, not anonymous. Confidential antibody testing means that both you and the doctor will know your results, which may be recorded as a written report in your medical file. As a permanent record in your medical file, the information may be available to insurance companies and public agencies.
    • With confidential testing, the local or state health department may be notified and thus try to contact you to be sure that you received the test results, understood them, and were referred to HIV care.
    • Virtually every state has passed laws dealing directly with HIV or AIDS. Because laws may vary among states, it is prudent to be informed prior to consenting to an HIV test. Call your state or local health department to find out what the laws are in your state.

How Are HIV Tests Performed? How Long Does It Take to Get Results? What Are the Different Types of HIV Tests?

HIV tests are done on blood drawn from the arm or a finger prick, or on oral fluid (saliva).

HIV tests can be divided into two groups, rapid tests and standard tests. Results for the rapid tests are typically reported in 20 minutes or less, at the testing site while you wait. Standard tests are sent off to the lab, and results typically take 24 to 48 hours. If you test positive with a rapid test, more blood will usually be drawn and sent to the lab for a confirmatory test to be sure that the rapid test result was not falsely positive.

There are currently tests for three markers for HIV infection:

The NAAT (nucleic acid amplification test) looks for HIV virus RNA or DNA. This is the first test to turn positive after HIV infection and may show infection as early as 10 days after infection and as late as 30 days. It has a higher rate of false-positive results, however, and is typically reserved for instances in which early infection is suspected.

HIV antigen tests look for actual proteins produced by the HIV virus. This is the next test to become positive after HIV infection, and the test usually turns positive as early as 18 days after infection and up to four weeks.

HIV antibody tests look for the antibodies produced by the infected person in response to HIV infection. The older, traditional HIV tests and the oral HIV tests both test for HIV antibody. Since these antibodies are produced in response to HIV infection, they can take anywhere from four weeks to three months to appear after HIV infection.

Most modern HIV tests are called fourth generation tests and look for both HIV antigen and antibody in various combinations. Fourth-generation tests can be either rapid (done in 20 minutes while you wait) or standard (sent off to the lab for reporting in one to two days). Although they can often detect infection earlier, it can take up to four weeks after HIV infection for the test to become positive. This four week period is called the window period. If you are exposed to HIV and have a negative HIV test during the window period, then you will need to have another test after the window period has passed in order to be sure that you are HIV-negative. If the fourth-generation test is positive, it usually is sent for a confirmation test that can be an antibody test or NAAT.

The oral HIV test and most of the home HIV tests are antibody tests. It can take from four weeks up to three months after infection for the body to produce enough antibodies to HIV to be detected by these tests. This three month period is called the window period. If you are exposed to HIV and have a negative HIV antibody test during the window period you will have to be retested after three months in order to be sure that you are HIV-negative.

Currently, there is no FDA approved vaccine effective against HIV.

You can also test yourself anonymously for HIV at home. Currently, there are two FDA-approved home tests: the "Home Access HIV-1 Test System" and the OraQuick In-Home HIV Test. The test kits can be found at most drugstores at a cost of $35-$70.

  • The Home Access testing procedure involves pricking your finger, placing drops of blood on a specially treated card, and then mailing the card in for testing at a licensed laboratory. People who use this test are given an identification number to use when phoning for the test results in three business days.
  • The OraQuick test involves swiping the gums for saliva, and you can get the results in 20 minutes.
  • Both of these home tests use traditional ELISA methods to detect antibodies and are reliable, but follow-up confirmation testing at a testing center is recommended if positive.
  • The window period for these tests is up to three months, so you if are exposed to HIV and test negative, you will need to retest in three months.

Why Is HIV Testing Counseling So Important?

Counseling is an essential part of HIV antibody testing and should always be performed before and after testing regardless of HIV status. Counseling is mandatory in most anonymous testing sites.

  • Counseling prior to the test will help you understand the results of your test, learn how to protect yourself from the virus, and gain the knowledge of how to prevent the spread of HIV if you should become infected. The counselor will explain the following:
    • The test and how is performed
    • AIDS and the ways HIV infection is spread
    • Ways to prevent the spread of HIV
    • The confidentiality or anonymity of the test results
    • The meaning of possible test results
    • Who you might tell about your result
    • The importance of telling your sexual and drug-using partner(s) if the result indicates HIV infection
  • Post-test counseling is equally as important. A negative test result can still miss a very recent HIV infection and does not mean you are immune to HIV. Behaviors that can transmit HIV include having unprotected sexual intercourse with an infected person or sharing needles or syringes with an infected person. Your post-test counselor will discuss these behaviors with you and the implications of the window period.
    • If you test positive for HIV antibodies, the counselor will help in referring you to a doctor who specializes in treatment and monitoring of HIV.
    • If you do not have health insurance, or if you will depend on public sources, you may need special assistance to get treatment, and a counselor can help you find these resources.
    • A counselor can also help in the notification of partners and refer you to a support group for people with HIV as a means of coping with the disease.

CDC Recommends HIV Testing for All Pregnant Women

The U.S. Centers for Disease Control and Prevention (CDC) recommends that all pregnant women and newborns of women whose HIV status in unknown be tested.

  • Without medical treatment, a mother infected with HIV has about a 25% chance of having a baby born with HIV.
  • Medical treatment with antiretroviral medication during pregnancy and labor has been shown to dramatically reduce the risk of transmission of HIV.
  • For more information on HIV/AIDS and HIV testing, contact the Centers for Disease Control National AIDS Hotline at 800-342-AIDS (800-342-2437).

For More Information on Free HIV Testing

Centers for Disease Control and Prevention, National HIV Testing Resources

AIDS.org, Comprehensive Guide to HIV Testing

Reviewed on 1/19/2018
Sources: References
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