About the Test
Purpose of the test
The purpose of HIV tests is to determine the presence of an HIV infection typically using blood, oral fluid, or also urine samples. HIV tests may be used as a routine screening test, as a diagnostic test after possible exposure to HIV, or in patients with symptoms of an HIV infection.
What does the test measure?
HIV tests detect the presence of the HIV virus genetic material, antigens, and/or antibodies. If these substances are detected, the test returns a positive result for HIV.
There are three types of HIV tests available:
- Antibody test: The body produces antibodies after an HIV infection. It can take weeks to produce antibodies, so HIV antibody tests can only detect HIV from three to 12 weeks after infection.
- Antigen/antibody test: Foreign substances that activate an immune response, antigens appear before the body produces antibodies. So antigen/antibody tests can detect an HIV infection earlier than antibody tests, within two to four weeks of becoming infected.
- HIV viral load test: In addition to detecting an HIV infection, viral load testing can detect how much of the virus is in the blood. Although this type of testing can detect an HIV infection earlier than other HIV tests, it’s very expensive and is typically only used when someone has symptoms or a possible exposure to HIV.
When should I get an HIV test?
Since HIV is primarily a sexually transmitted disease (STD), testing is very important for those who are sexually active – particularly those who have multiple partners. HIV tests are recommended for:
- Babies born to HIV-positive mothers
- People seeking treatment for any other STD
- People who already have tuberculosis or hepatitis
- People who have unprotected sex with multiple partners
- Those who are pregnant, or planning to become pregnant
- Those who use shared needles to inject drugs
It is important to note that not everyone who is infected with HIV will develop early symptoms. However, two to four weeks after HIV exposure, you may experience the following symptoms:
- Muscle aches
- Night sweats
- Prolonged diarrhea
- Rash on the torso
- Sore throat
- Spotting on the skin or in the mouth
- Swollen glands or lymph nodes
- Unexplained fatigue
- Unexplained weight loss
These symptoms are not specific to HIV and the presentation (or not) is not enough to predict your HIV status – only an HIV test can confirm a positive case. It is important to consult a health care professional if you think you may have been exposed to HIV.
Finding an HIV Test
How to get tested
HIV tests are conducted at doctor’s offices, medical clinics, and many community-based organizations. Taking an HIV test does not typically require a doctor’s orders, although HIV tests may be ordered by a doctor as part of a routine health screening.
Can I take the test at home?
At-home HIV tests are a convenient way to take an HIV test in a private location. Testing for HIV at home is a form of screening that requires additional follow-up if preliminary results are positive. At-home HIV tests can be obtained online, at a pharmacy, or at health departments and community-based organizations.
How much does the test cost?
The cost of an HIV test is usually covered by insurance without a copay, although specific costs depend on a person’s insurance coverage and where the test is performed. Check with your health plan and health care provider for specific cost details.
At-home HIV tests cost below $50. Health departments and community-based organizations may provide HIV self-test kits for free or at a reduced cost.
Taking an HIV Test
HIV testing involves an initial test and, if the preliminary result is positive, additional follow-up testing to confirm these results. Laboratory testing uses blood samples to look for evidence of HIV. Rapid testing provides faster results from oral fluid, a finger-stick, or urine and can be administered on-site in a variety of health care and community settings.
Before the test
For an HIV test administered in a medical facility or lab, there is no preparation needed before the test. The type of HIV test administered depends on a person’s reason for getting tested, so it’s important to talk to a health care professional if you believe you’ve been exposed to HIV or have experienced symptoms of an HIV infection.
At-home HIV test kits offer detailed instructions for collecting a sample and administering the HIV test. Although test kits are designed to make the process straightforward, it’s important to read all instructions to reduce errors and contamination.
During the test
When an HIV test is administered in a medical facility or lab, a health care professional will instruct you on how the blood, oral fluid, or urine sample will be taken.
Laboratory-based HIV tests will take a blood sample through a vein in your arm. This process takes less than five minutes and some people feel minor discomfort, such as pain or stinging where the needle is inserted into the arm. There is no pain when the sample is taken from an oral swab or urine.
At-home HIV tests use a sample of oral fluid to check for HIV. During this test, a device is used to swab the gums and inserted into a vial of testing solution. After 20-40 minutes, results can be read.
After the test
If blood was drawn from a vein, pressure is placed on the puncture site with a clean gauze or cotton ball. You may be instructed to keep the gauze in place to reduce bruising. Although there are slight risks from a blood draw, including infection and lightheadedness, there are no restrictions on activity after the blood draw is complete.
Rapid HIV tests that use blood from a finger-stick, oral fluid, or urine require no precautions or post-test restrictions. Some at-home HIV tests require samples to be mailed to a certified laboratory according to the instructions contained in the test kit.
HIV Test Results
Receiving test results
How long it takes to get results from an HIV test depends on the type of test administered:
- Laboratory tests: Both viral load and antigen/antibody tests performed in a laboratory require blood to be sent out for testing. The results of these tests often take several days before being available.
- Rapid antibody tests: These tests are performed on oral fluid or blood from a finger-stick. Results for these tests are ready in 30 minutes or less.
- Rapid antigen/antibody tests: Using blood from a finger-stick, the rapid antigen/antibody tests take 30 minutes or less to produce results.
- At-home oral fluid antibody tests: At-home HIV testing uses a sample of oral fluid and provides results within about 20 to 40 minutes.
For HIV tests conducted at a medical facility or community organization, a trained staff member will report your results and be available to answer any questions. Health care providers can also discuss your risk factors for HIV and advise you on the next steps if the results of the HIV test are positive.
After rapid testing, you wait for the results in the facility. For laboratory testing that can take up to several days to receive results, you may be asked to schedule a follow-up visit or consent to receiving results by telephone.
For at-home HIV testing, results can be read according to instructions contained in the test kit. These test kits may also contain an information booklet designed to instruct you on what to do once you have obtained your test results.
Interpreting test results
HIV test results are reported as positive, negative, or indeterminate. The results of HIV tests should be interpreted with caution. Follow-up testing is often necessary. Patients must take into account the test’s window period, the time between when a person gets infected with HIV, and when a test can detect the infection.
No test can detect HIV immediately after infection and all HIV tests have a window period. The length of the window period varies from test to test, ranging from about two to 12 weeks. At-home tests have a window period of about three months.
A negative HIV test result means that HIV antibodies or antigens weren’t detected in the test sample. If a person has had no potential exposure to HIV within the test’s window period, they are considered negative for HIV infection. If a person has had potential exposure within the test’s window period, HIV testing must be repeated after they are past the window period.
Positive results on an HIV test need to be confirmed through follow-up testing. Laboratory tests conduct the second test on the same blood sample as the first test. If you receive a positive result on a rapid test, the health care professional will schedule a second confirmatory test. At-home HIV-positive test results must be confirmed in a laboratory or health care setting. If the follow-up test result is also positive, a person is considered HIV-positive.
Indeterminate results on an HIV test occur when an initial screening test is positive, then a follow-up test is negative. In this situation, doctors may order a more detailed HIV viral load test for additional confirmation.
You may want to ask your doctor follow-up questions, such as:
- Will any other tests be required to confirm my HIV status?
- What precautions should I take to protect others?
- Are there counseling options available?
- Are there community-based organizations near me to connect me to HIV/AIDS resources?