HIV Testing: Types, Frequency, Expectations and Results Explained

Undergoing an HIV test can determine if you have the human immunodeficiency virus (HIV), a type of sexually transmitted infection (STI) that weakens the body's ability to fight infections. In some cases, HIV can progress to acquired immune deficiency syndrome (AIDS), which can be life-threatening.

It is crucial to get tested for HIV because early detection allows for timely treatment. Current treatments for HIV can effectively strengthen the immune system and control the virus. Early intervention can also prevent the development of AIDS.

What are three tests for HIV?

Your healthcare provider may use one of three types of tests to diagnose HIV. Depending on the test, you will need to provide either a blood sample or an oral fluid sample. Oral fluid consists of cells from your mouth and is different from saliva.

• Nucleic Acid Test (NAT): The NAT can detect HIV RNA, which is the genetic material of the virus. This test can determine the amount of virus (viral load) in your blood. The NAT is a comprehensive laboratory test that requires a blood draw and may be expensive.
• Antigen/Antibody Test: The antigen/antibody test checks for both antigens and antibodies associated with HIV. Antigens are substances that trigger the immune system to fight HIV. The p24 antigen is one such substance that becomes present in the blood if you have HIV. This test also looks for HIV antibodies, which are produced by your immune system to combat the virus. Typically, antigens appear in the blood before antibodies do.
• Antibody Tests: These tests are used to detect the presence of HIV antibodies in the blood, indicating exposure to the virus.

For HIV screening, you may undergo either an antibody test or a combination antigen/antibody test. If the initial results are positive, follow-up testing will be necessary to confirm the diagnosis.

When should you conduct an HIV test?

Everyone aged 15 to 65 years should undergo an HIV test at least once in their lifetime. HIV may not always show symptoms in its early stages. Private HIV testing may be the only way to detect the virus and possibly prevent its spread to others. You should get tested if you are at increased risk for HIV exposure or if you are pregnant.

HIV Testing for High-Risk Groups

HIV can spread through bodily fluids exchanged during intercourse and through blood. You are at higher risk if you are likely exposed to fluids from an HIV-infected person. Engaging in unprotected sex with an HIV-positive partner increases the risk of contracting HIV.

You may require regular HIV testing if:

• You engage in anal, oral, or vaginal sex with an HIV-positive partner or a partner whose HIV status is unknown.
• You are a person with a penis who has sex with other people with penises.
• You have sex with multiple partners or your partners have multiple sexual partners.
• You share needles for injecting drugs.
• You have a sexually transmitted infection other than HIV.

Getting tested regularly means you should have a test at least once a year or more frequently. Men who have sex with men should get tested every three to six months. Ask your healthcare provider how often you should get tested.

You should also get tested if you have been sexually assaulted. Contact a healthcare provider to start HIV post-exposure prophylaxis (PEP). This is a series of medicines to prevent HIV. You should start taking them within 72 hours of possible exposure for them to be effective.

HIV Testing During Pregnancy

An HIV test is recommended during pregnancy, usually in the first trimester. This is because HIV can be transmitted from the mother or gestational parent to the fetus and through chest or breast milk. Receiving treatment early in pregnancy can prevent transmission of the virus to your newborn.

If you are pregnant and considered at higher risk for contracting HIV, you should be retested at least two to three times during pregnancy.

Where can you get an HIV test?

You can get tested at your healthcare provider's clinic or office. HIV tests can also be conducted at home using a self-test kit.

How does an HIV test work?

Private HIV testing detects the presence of HIV in your blood or oral fluid. This can include the virus itself, such as HIV antigens, or antibodies produced in response to the virus. If you test positive, further testing will be required to confirm the results. If you test negative, it means you likely do not have the virus. However, it's important to ensure that you take the test at the right time, as it can take some time after exposure for an HIV test to detect the virus.

How soon after HIV exposure can a test detect the virus?

HIV tests cannot detect the virus immediately after exposure. It takes time for your body to produce antibodies in response to the virus. The window period is the time gap between exposure and when a test can detect the virus. You should get tested after the window period, which varies from person to person and by the type of test.

• A Nucleic Acid Test (NAT) has the shortest window period. It can detect an HIV infection from 10 to 33 days after exposure.
• Antigen/Antibody tests can detect the infection from 18 to 45 days after exposure for blood draw tests, and from 18 to 90 days after exposure for finger-prick tests.
• Antibody tests can detect the infection from 23 to 90 days after exposure.

If your test result is negative and you believe you have been exposed to HIV, it is important to get retested.

How do you prepare for an HIV test?

You do not need to do anything special to prepare for tests that involve drawing blood. For at-home tests that involve collecting oral fluid, you may need to avoid eating or drinking for at least 30 minutes before taking the test. Make sure you follow the instructions provided with the kit.

What should you expect during an HIV test?

Your experience will depend on the type of test you undergo and where you have it performed.

Lab HIV Tests

Most HIV tests involve a healthcare professional drawing blood and sending it to a laboratory for analysis. These tests may be conducted in your provider's office or at a clinic. If you test positive, your provider will conduct additional testing to confirm the results. Below is the sequence of HIV tests typically performed:

• Test #1: An antigen/antibody test checks for HIV antigen p24 and HIV antibodies. If you test positive, a second test will be conducted to confirm the results.
• Test #2: An antibody test checks for antibodies related to two types of HIV – HIV-1 and HIV-2. A second positive result confirms that you are HIV-positive. If the results are inconclusive, a third test is required.
• Test #3: A Nucleic Acid Test (NAT) checks for the presence of HIV in your blood

Rapid HIV tests

Rapid tests check your blood or oral fluid for HIV antibodies. There is also a rapid HIV antigen/antibody test. The healthcare professional collects blood either through a finger prick or from a vein. For oral fluid, a mouth swab is used.

Some rapid tests deliver results within five minutes. If the result is positive, you will need to follow up with your healthcare provider to conduct additional testing before confirming your HIV status.

At-home HIV tests

An at-home test is a rapid HIV test that detects the presence of HIV antibodies. You swab your upper and lower gums to collect an oral fluid sample. You then place the swab in a vial, which shows a positive or negative result within 20 to 40 minutes. If the results are positive, further testing will be required to confirm the results.

What are the risks of this test?

An HIV test does not have any risks. But you may feel some discomfort during a blood draw or finger prick.

When should you expect the test result?

The type of test you undergo will determine how soon you can receive the results. Rapid tests, such as antibody and antigen/antibody tests, can deliver results within 20 minutes.

What type of results will you get, and what do the results mean?

The test results will be either positive or negative.

• A positive result means the test detected signs of the virus. This result indicates that you may have HIV, but further testing is required to confirm the diagnosis.
• A negative result means the test did not detect signs of the virus. This result suggests that you do not have HIV or that it is too early for the virus to be detected.

What should you do if the results are negative?

If the test result is negative and you have taken the test soon after HIV exposure, consider taking a second test after the window period has passed. The second test will confirm your negative result if you were tested before the infection became detectable in your body.

In the case of a negative result, it is important to continue protecting yourself in the future. Talk to a healthcare provider about whether PrEP (pre-exposure prophylaxis) is the right choice for you. Taking PrEP daily can reduce the risk of acquiring HIV from sexual contact by almost 99%. For people who use IV drugs, it can reduce the risk by 74%. It is crucial to take PrEP as prescribed if you are HIV-negative and your partner is HIV-positive. If you are taking PrEP, it is also advisable to use a condom or dental dam to further reduce the risk of contracting HIV as well as other STIs.

What should you do when you have positive results?

If you receive a positive test result, you will need to undergo further testing with your healthcare provider. Once the diagnosis is confirmed, you will work with your provider to develop a treatment plan. Your healthcare provider will assess the stage of HIV progression and recommend medications to manage it.

Antiretroviral therapy, the treatment for HIV, helps your body fight the virus and prevents the progression to AIDS. When used consistently, it can prevent the disease from advancing and enable you to live a healthy life. It's important to discuss your diagnosis with your sexual partner, and both of you should get tested. If you and your partner have engaged in unprotected sex, there is a risk of transmitting the virus to them.

When should you conduct an HIV test?

You should conduct an HIV test at least once in your life, especially if you are at higher risk of exposure. It's important to take the test after the window period, which is the time when the test can accurately detect the virus.

Can a blood test detect HIV?

An HIV blood test involves drawing blood, similar to other blood tests. However, an HIV test differs in how your blood is tested after it is sent to the laboratory. Your blood will be specifically tested to detect signs of HIV, including antibodies, antigens, or HIV RNA.

What is the difference between an HIV-1 and an HIV-2 test?

There are two types of HIV: HIV-1 and HIV-2. Some antibody tests can detect whether you have HIV-1, HIV-2, or both types of antibodies in your blood. HIV-1 is more common and spreads more easily than HIV-2.

If you are concerned about being HIV positive, talk to family members and trusted friends. Speak with a counselor who can support you through the testing process and help you understand the results. While receiving a positive result can be frightening, it is important to inform your sexual partner and begin treatment. HIV treatments have advanced significantly, and many people living with HIV lead healthy lives. You can get tested for HIV here to understand your current condition.