What Is an HIV Test?

What to expect when undergoing this test

A lab technician performing a rapid HIV blood test.
A lab technician performing a rapid HIV blood test.

Martin Harvey/Getty Images

An HIV test is used to determine if you have been infected with the human immunodeficiency virus (HIV). While the test is commonly performed on a blood or saliva sample, a newer urine-based test was approved for use in the United States in 2015. While both point-of-care and at-home testing options are extremely accurate if used correctly, they can return a false-negative result if you test too soon after an exposure.

Purpose of Test

There are an estimated 1.2 million people living with HIV in the United States, 25 percent of whom remain undiagnosed. Each year, an additional 50,000 people are infected.

In response, the U.S. Preventive Services Task Force has issued updated guidance recommending that every American between 15 and 65 undergo HIV testing as part of a routine doctor's visit, such as a physical exam. Testing is also recommended for pregnant women to avoid passing the virus from mother to child.

Annual or even biannual tests may be advised for people at a high risk of infection, including:

An HIV test may also be given after one becomes aware of a partner's HIV-positive status and during a medical evaluation after sexual assault.

Types and What They Assess
There are both indirect and direct methods of HIV detection. Indirect methods do not detect the virus but rather proteins, called antibodies, that are produced by the immune system in response to the virus. Direct testing methods detect either antigens (proteins on the surface of the virus) or RNA (the virus’ genetic material).
There are a few testing options, which vary in their speed, accuracy, and ease of use:

  • Rapid point-of-care tests can deliver preliminary results in around 20 minutes. These may require a blood drop from your finger, an oral swab from your gums, or a sample of urine. Of these, the preferred method is the blood-based combination HIV antigen/antibody (Ag/Ab) test.
  • Standard point-of-care tests are lab-based tests that detect HIV antibodies only. Also known as the HIV ELISA, the test requires a blood draw. The results are usually returned within five to 10 working days. The test is less commonly used today and has been largely replaced by the combination HIV Ag/Ab test.
  • Rapid at-home tests are saliva-based antibody tests that can be purchased online or at many retail drugstores. While less accurate than a point-of-care test, the test offers privacy and can deliver results in around 20 minutes.
  • Home collection kits can also be purchased online. This antibody test requires a drop of blood placed on a test card, which you then send to a lab via express mail. You can then receive the results either by phone or online as early as one business day after your sample is delivered.
  • Nucleic acid tests (NAT) are blood-based tests that detect HIV RNA. While expensive, the NAT can detect HIV earlier than other forms of testing and may be appropriate if you have had a recent high-risk exposure or are experiencing acute symptoms of early infection. The NAT is also used to screen donated blood or test newborns suspected of having HIV. Results are usually returned within a couple of days.

Any positive result—called the preliminary positive—would require a second confirmatory test to ensure the diagnosis is correct. The only exception is the NAT, which does require confirmation.

Test Accuracy

HIV tests are highly accurate if used correctly. With that being said, some testing methods are more reliable than others.

By and large, point-of-care tests are more accurate than home-based tests (due in part to home user error), while blood tests tend to be more accurate than saliva or urine tests (due to the higher concentrations of HIV in blood). Improper sample collection or storage can also undermine the accuracy of a test.

With that being said, clinics in the United States report a 98.5 percent accuracy rate when using an antibody test and a 99.9 percent accuracy rate when it is combined with a confirmatory test. This translates to one false-positive result for every 250,000 tests. Newer generation tests promise even better results.

By contrast, at-home tests are far less sensitive than point-of-care tests and may have as many as one false negative per every 12 tests.

Certain diseases can also trigger a false-positive test result, including syphilis, lupus, and Lyme disease. Confirmatory testing will almost always weed out these incorrect findings.

Risks and Contraindications

There are few risks associated with HIV testing. If a blood draw is required, you may experience soreness, swelling, and bruising at the injection site. Lightheadedness and infection are also possible.

If you are afraid of needles or squeamish about blood, advise the nurse or phlebotomist in advance. Others testing options may be available. Additionally, if you have hemophilia or are taking blood thinners, a child-sized butterfly needle may be used to reduce the risk of bleeding.

There are no contraindications for HIV testing.

Before the Test

The HIV test requires no preparation other than your readiness to take the test. With that being said, HIV remains a highly stigmatized disease, and people often avoid HIV testing out of fear of disclosure.

If you are concerned about your privacy, find a clinic that offers either confidential testing (in which your name is shared only with your health provider, your insurance company, and a government reporting agency) or anonymous testing (where your name is shared with no one).

Timing

Timing is an important part of HIV testing. If you have been infected with HIV, there will be a period of time, called the window period, when the test cannot deliver an accurate result. 

Because HIV tests generally detect antibodies and/or antigens, you need to wait until your body has produced enough of these to elicit a positive result. If you test too early, you will get a false-negative reading. Even with the NAT, you need to wait until the virus has replicated to detectable levels.

The window period can vary by the test used and ranges from as many as 55 days for an at-home test to as little as seven to 14 days for a NAT. Because detectable levels can also vary by individual, most clinics will advise you to wait no less than:

  • Three weeks before getting a NAT
  • One month before getting a combination HIV Ag/Ab test
  • Three months before getting any of the other HIV tests

The procedure itself involves three steps: pre-test counseling, the HIV test, and post-test counseling. Depending on the test being performed, the process can take 30 minutes to 45 minutes. Walk-in centers may take far longer.

Location

HIV tests are available at many medical and public health facilities. These include hospitals, clinics, retail pharmacies, community-based HIV organizations, antenatal and family planning clinics, youth drop-in centers, mobile testing sites, and drug and alcohol treatment centers.

To find a testing site near you, use the online locator offered by the U.S. Department of Health and Human Services. Many of the sites offer walk-in testing. Others require an appointment.

Food and Drink

There are no food or drink restrictions for an HIV test. However, if you are using an at-home oral test, avoid brushing your teeth or using mouthwash 30 minutes beforehand, as this may affect the results.

What to Bring

Even if you are undergoing anonymous testing, the facility may require government-issued ID to confirm your residency. Call in advance for details. You should also check to see if they accept your insurance, if you have a plan. If so, bring your insurance card.

You may also want to consider bringing someone with you if you are unsure how you might react to a positive HIV diagnosis. Having support can be very important.

Cost and Health Insurance

The cost of an HIV test can range anywhere from $20 to $40 for a non-reactive (negative) test and $90 to $150 for a confirmed reactive (positive) test. Most insurance plans, including Medicare and Medicaid, will cover the cost in full as part of the Affordable Care Act’s essential health benefits.

By contrast, an at-home HIV test can cost between $25 and $50, while mail-in versions can range in price from $50 to $90. It is important to note that, while point-of-care tests are typically covered by insurance, at-home test kits may not be. Check with your insurance provider to better understand your benefits in this regard.

If you are uninsured, you can find low- to no-cost testing sites through the GetTested locator offered by the Centers for Disease Control and Prevention.

HIV Disclosure Laws

Irrespective of whether your HIV test is anonymous or confidential, any positive test result will be reported to your local health department who will, in turn, disclose the information—without your name—to the Centers for Disease Control and Prevention (CDC) in Atlanta. The information is not shared with any other government agency.

A positive result may also be shared with your insurance company and the doctor who referred you for testing. It cannot be shared with any other doctor or agency without your expressed written consent under the Health Insurance Portability Accountability Act (HIPAA) of 1996.

Many states and some cities have partner-notification laws, meaning that your health provider may be legally obligated to tell your sex or needle-sharing partner if you test positive for HIV. Your name or personal information is not shared in the disclosure.

If you are married and test positive for HIV, be aware that health departments funded by the federal government's Ryan White HIV/AIDS Program are required to show "good faith" efforts in notifying married partners of the result. Implementation of this requirement varies significantly.

Other Considerations

It is a mistake to think that there is nothing you can do if you’ve been recently exposed to HIV. If you have had sex without a condom, shared needles, or have some other form of high-risk exposure, you may able to avert the infection by starting HIV post-exposure prophylaxis (PEP) within 48 hours.

PEP involves a 28-day course of two or three antiretroviral drugs depending on the severity of your exposure. Used by healthcare workers and in cases of rape, the strategy may reduce your risk of infection by as much 79 percent.

During the Test

On the day of the test, after registering and confirming your insurance information, you will be asked to sign a consent form acknowledging that your test results may be shared with the relevant agencies and individuals as directed by HIPAA. Speak with the office administration if you do not understand any part of the consent form.

Many sites will also ask you fill out a questionnaire to get some background information on you, including your ethnicity, sexual orientation, sexual activity, and substance use, and whether you have had an HIV test before. Some of the information will be used for confidential reporting purposes; some to assist with counseling.

Pre-Test

Pre-test counseling is performed in a private room with a qualified health professional. During the counseling, you may be asked about the recent exposure, if there was one, as well as your sexual or recreational drug practices. The questions are not meant to judge or embarrass you; rather, they help the counselor gain a better understanding of your personal risk of infection.

The counselor will then explain what HIV and AIDS are, how the test is performed, what a window period is, and what a positive and negative result means. If it is determined that you are testing too soon, the counselor may request that you come back when the test is more likely to be accurate.

Feel free to ask any question you need. There is no such thing as a bad question.

Throughout the Test

The testing procedure in a clinic can vary based on whether you are taking a rapid HIV blood or oral test, or an HIV antibody blood or saliva test. (The urine test, while approved, is rarely used in a clinical setting, in part because it is less accurate than any of the other tests.)

A rapid HIV blood test is performed as follows:

  1. Your finger is cleaned with an antiseptic wipe.
  2. Using a spring-loaded tool called a lancet, the health professional pricks your finger to draw a drop of blood.
  3. The blood is drawn into a tiny glass tube called a pipette, which is then placed in a reagent called a buffer.
  4. The buffer and two other chemicals (a dying agent and clearing solution) are poured into a plastic well called a membrane.
  5. After 15 to 20 minutes, the membrane is checked. If the membrane has one dot on the bottom, the test is non-reactive (negative). If the membrane has two dots, the test is reactive (preliminary positive).
  6. A confirmatory blood test is then performed; results are available a few days later.

A rapid HIV oral test is performed as follows:

  1. An oral swab called a wand is swiped between your teeth and upper and lower gum. The wand should be swiped no more than once.
  2. The wand is placed in a buffer solution for 20 minutes.
  3. The wand has a results window similar to one on an at-home pregnancy test. If the window in the handle has one line, the test is non-reactive (negative). If the window has two lines, the test is reactive (preliminary positive).
  4. A confirmatory blood test is then performed. You will get your results the same day you take the test.

Note: If you used a home kit, the toll-free support helpline listed on the test's instructions will advise your further.

An HIV antibody blood test is performed as follows:

  1. An elastic band is placed on your upper arm to make a vein swell.
  2. The skin around the planned injection site is cleansed with an antiseptic swab.
  3. A wing-shaped device called a butterfly needle is inserted into the vein. This needle, which is attached to a narrow catheter, is less prone to jiggling as your blood is being drawn than other types.
  4. Between 1 to 4 milliliters (mL) of blood are extracted into a vacuum-sealed test tube called a vacutainer.
  5. The needle is then removed and your arm bandaged.
  6. The tube is sent to a lab. If the sample is reactive (preliminary positive), the lab immediately runs a confirmatory test using the same blood sample.
  7. You will be informed of your results in a week or two.

An HIV ELISA saliva test is performed as follows:

  1. An oral swab called a wand is placed between your cheek and gum for two to five minutes.
  2. The wand is placed in a buffer solution.
  3. The wand handle is then snapped off.
  4. The buffer solution is sealed and sent to the lab.
  5. If the sample is reactive (preliminary positive), the lab immediately runs a confirmatory test using the same sample.
  6. You return for your test results in a week or two.

After the Test

Some people will tell you that the hardest part of an HIV test is not taking the test but waiting for the results. This is especially true if you have a preliminary positive result and have to wait several days or more for the final results.

The wait can often be agonizing; so much so, in fact, that as many as one in 15 people will not return for their results, according to a study published in the International Journal of STDs and AIDS.

There are several things you can do to remain composed during the wait:

  • Surround yourself with friends and family who support you.
  • Take things one step a time. Do not spend hours scanning the web for all of the "what ifs."
  • Exercise to help elevate your mood and fight depression.
  • Avoid alcohol, recreational drugs, or even caffeine to remain calm and present.
  • If worry begins to consume you, remind yourself that there is effective treatment and ways to pay for it whatever your income.
  • If you are unable to cope and don't have someone to talk to, call the 24-hour, toll-free HIV hotline in your state for a referral to a qualified counselor in your area.

Interpreting the Results

The time it takes to get your results can vary. Many states mandate that the test results be delivered only in person. While some states will allow doctors to deliver negative results over the phone, the practice is frowned upon by most health professionals given that it doesn't allow for adequate post-test counseling and poses the potential of a breach of confidentiality that you've been tested (something you may not want shared). HIV test results are not sent by mail.

Test results are interpreted as follows:

  • If the preliminary test is non-reactive, you are HIV-negative, meaning that you have either not been infected or have tested too soon. While you won't require further testing (unless the timing of your test was not optimal), you will be advised on ways to reduce your future risk and whether routine testing is needed if you are at high risk of infection.
  • If the preliminary test is reactive, the result is considered a preliminary positive. To confirm the result, the lab will use a more sophisticated test called the HIV differentiate assay and possibly the NAT. If the confirmatory tests are both non-reactive, you can be assured with a high level of confidence that you are HIV-negative.
  • If your preliminary and confirmatory tests are both reactive, you are HIV-positive, meaning that you have been infected with HIV. Post-test counseling will be focused on both your emotional and medical needs.

Post-test counseling is always performed, no matter your test results. The aim of the counseling is two-fold: to help you understand what the results mean and to provide you the "what’s next" information you need to stay safe and healthy.

Remember that a positive result may be shared with the CDC, your insurance company, or your doctor, or certain individuals in accordance with the rules you agreed to before your test. If your confidentiality is breached, you can file a complaint with the Department of Health and Human Service and seek legal damages as afforded under the laws of your state.

Follow-Up

Upon receiving an HIV-positive diagnosis, you will be advised that there are treatment options and support systems to link you to medical care. You may also be referred to a care navigator who can assist you with referrals and any financial, emotional, family, legal, or drug treatment services you need.

If you feel overwhelmed, you can request to discuss these things on another day or use the time to ask as many questions as you need. Coming to terms with an HIV diagnosis is a process. Don’t feel rushed.

However, if you are ready to proceed and the test was performed in a clinic or hospital, you may be asked to undergo additional tests called a CD4 count and HIV viral load. The CD4 count measures the number of immune cells (called CD4 T-cells) in your blood and helps establish how strong your immune system is. The viral load uses a similar technology to the NAT and counts how many viruses there are in a microliter (µL) of blood.

Both of these tests help establish your baseline status before treatment and will be routinely repeated to assess your response to therapy.

HIV treatment should ideally be started at the time of diagnosis. Genetic tests may be used to identify which drugs work best for you. The drug therapy itself typically involves a once-daily dose and, if taken as prescribed, can ensure a normal quality of life and a near-normal life expectancy.

You will have ongoing medical evaluations to monitor your condition for the rest of your life, the schedule for which will be determined by your doctor.

A Word From Verywell

Receiving an HIV diagnosis can be a life-altering event, and there is often no way to know how you will react to the news. Whatever your response, accept that it is normal. Some people might even feel a sense of relief from no longer having to wonder about their status.

Whatever your reaction, it is important to remember that a positive diagnosis does not mean the same thing that it used to. Advances in HIV therapy are such that you can now live a long and healthy life and may never be faced with the prospect of a serious HIV-related illness or AIDS.

By knowing your HIV status, you can make an informed choice on how to protect others from infection and yourself from reinfection.

This to not suggest that living with HIV is without its challenges. If you are having trouble coping, consider joining a support group or seeking one-on-one counseling from a qualified therapist.

On the other hand, if you are experiencing extreme depression or anxiety, ask for a referral to a psychiatrist who may be able to offer medications and therapy to help you better cope.  

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