About our HIV Viral Load Test
Purpose of the test
The purpose of testing for HIV viral load is to measure the amount of viral RNA, which is the genetic material of the virus, in a small sample of a patient’s blood. This test may be used to diagnose HIV as well as plan and monitor HIV treatment.
Diagnosing HIV: HIV viral load testing is one test that can determine if a person has an HIV infection. There are three types of diagnostic HIV tests: nucleic acid amplification tests (NAATs), antigen/antibody tests, and antibody tests. The HIV viral load test is a type of NAAT test.
Although NAAT testing can detect infection within 10 to 14 days after exposure, it is not routinely used to screen patients without symptoms or exposure to the virus. An HIV viral load test may be ordered to diagnose patients only after a high-risk exposure or when patients are experiencing early symptoms of HIV. This test may also be used to diagnose HIV in infants.
Guiding HIV Treatment: Antiretroviral treatment (ART) is treatment for HIV used to suppress the virus and to prevent HIV from advancing to AIDS. HIV viral load testing is used to guide treatment for patients with HIV by providing information about when to begin ART, which regimen of ART medications may be appropriate, and when to change to a new ART regimen.
Monitoring HIV: HIV viral load testing is used to understand a patient’s response to ART. After a person is diagnosed with HIV, viral load testing helps doctors monitor how well treatment is working. A viral load test is typically performed at the time of diagnosis to establish a baseline measurement. After antiretroviral therapy (ART) begins, testing is usually repeated within 2 to 8 weeks to confirm that the medications are reducing the amount of virus in the blood. Once treatment is stable and viral load is suppressed, testing is generally recommended every 3 to 6 months to ensure the virus remains under control and to detect any changes that may require treatment adjustments.
One goal of ART is to suppress the virus until the patient’s viral load is undetectable, which means it is too low to be detected on an HIV viral load test. People with sustained undetectable viral load cannot sexually transmit HIV.
Once a patient begins ART, it usually takes 3 to 6 months for the viral load to reach an undetectable level. When used to monitor treatment, viral load testing is used alongside a CD4 count test, which measures the amount of one type of white blood cell that is destroyed by HIV. Together, these two tests provide information about how well a patient’s treatment is controlling their HIV infection.
What does our HIV Viral Load test measure?
Most HIV viral load tests use polymerase chain reaction (PCR) technology to detect and measure HIV RNA in the blood. Results from an HIV viral load test are reported as the number of copies of HIV RNA found in a milliliter of blood. In general, lower numbers indicate better control of the virus. When treatment is effective, the goal is to reduce the viral load to an undetectable level, meaning the amount of virus is too low for the test to measure.
A low or undetectable viral load over time suggests that antiretroviral therapy is working well. Higher viral load levels may indicate that HIV is actively replicating and that treatment may need to be evaluated or adjusted. This is because when a person is initially infected with HIV, the virus begins to replicate and produce more and more copies of itself. CD4 cells are a type of white blood cell that are the main target of HIV. The virus invades CD4 cells and uses them to replicate.
In the early stages of HIV infection, the virus is often present in high amounts even though there may be few, if any, noticeable symptoms. Without treatment, the virus continues to replicate, and the viral load increases as the amount of CD4 cells decreases.
Several weeks after infection, the immune system begins to produce HIV antibodies meant to defend against the virus. HIV antibodies temporarily suppress the HIV viral load. Although a person’s initial symptoms may resolve after the production of HIV antibodies, the infection does not go away.
Unless an HIV infection is detected and treated, it may continue to destroy CD4 cells and slowly degrade a person’s immune system. Over time, the immune system can become so weakened that the disease begins to affect the body’s ability to fight infections and certain types of cancer.
When should I get an HIV viral load test?
Diagnostic testing for HIV viral load may be used in patients with a possible or known exposure to the virus who are suspected of having an acute HIV infection. An acute HIV infection describes the earliest stage of HIV infection when some people begin to develop signs and symptoms of this disease. Although up to 60% of people infected will not have symptoms during this period, when they do occur, symptoms of an acute HIV infection may include:
- Fever
- Swollen lymph nodes
- Sore throat
- Rash
- Muscle or joint pain
- Diarrhea
- Headache
- Nausea or vomiting
- Night sweats
- Mouth or genital ulcers
Infants born to a parent with HIV are tested multiple times during their first months of life because standard antibody tests cannot reliably diagnose HIV in newborns. Instead, doctors use HIV RNA tests that detect the virus itself. Current guidelines recommend testing at several stages: at birth, again at 14–21 days of age, between 1 and 2 months, and again between 4 and 6 months. Testing at these intervals helps doctors detect infection early while also confirming that infants who were exposed to HIV during pregnancy or delivery are not infected.
When used to guide treatment and monitor HIV, an HIV viral load test is typically ordered when a patient is first diagnosed. After this baseline testing, an HIV viral load test is ordered again when a patient begins ART and at regular intervals thereafter. Several factors can affect this timeline, including a patient’s ability to follow recommended treatment. Generally, HIV viral load testing occurs at the following intervals:
- After an initial diagnosis
- When starting ART
- Within 2 to 4 weeks after starting ART
- Every 4 to 8 weeks until the viral load is suppressed and undetectable
- Once the virus is undetectable, every 3 to 4 months during the first two years of ART
- Every 6 months in some patients who have undetectable viral loads for two years or longer
- If a patient changes their ART regimen due to side effects or because their viral load is suppressed, an HIV viral load test may be ordered after 4 to 8 weeks to confirm the effectiveness of the new treatment regimen.
After a patient’s viral load is undetectable on ART, patients may have occasional “blips” in which the viral load becomes detectable again for a short time. Although an isolated “blip” is not a sign that treatment is no longer working, some patients experience more significant increases in viral load that do indicate the HIV infection may have become resistant to ART or that treatment has failed. In patients with a drug-resistant virus, HIV viral load testing may be ordered 4 weeks after beginning a new ART regimen, then at 4 to 8 week intervals until the viral load becomes undetectable.
Finding an HIV Viral Load Test
How to get tested
HIV viral load testing is ordered by a physician or other health professional. Testing can be performed at a hospital, doctor’s office, or other medical setting. Results are usually available within 1 to 5 business days, depending on the laboratory.
Can I take the test at home?
HIV viral load testing requires a blood sample drawn by a health professional and is not available as an at-home test.
At-home HIV testing is available to screen undiagnosed patients for HIV, with both rapid and self-collection kits available.
How much does the test cost?
The cost of HIV viral load testing depends on where the test is performed and whether the patient has health insurance. Additionally, laboratory and other charges vary. Patients should discuss the costs of testing with their doctor, the laboratory, and/or their health insurance provider.
If paying for HIV testing and treatment is a concern, resources are available to help people with HIV gain access to medical care through the U.S. Department of Health and Human Services: How to Find HIV Treatment Services.
Taking an HIV Viral Load Test
An HIV viral load test requires a sample of blood. Usually, blood is drawn from a vein on the inside of a patient’s elbow or on the back of the hand.
Before the test
No preparation is required before having an HIV viral load test. Some health conditions and vaccinations may cause a temporary change in a patient’s HIV viral load, so patients should tell their doctor about recent illness, outbreak of herpes simplex, or vaccinations.
During the test
During an HIV viral load test, several steps are taken to draw a sample of a patient’s blood:
A puncture site on the patient’s arm is located and cleaned to kill germs on the skin.
The health care professional ties an elastic band around the upper arm to increase pressure and cause the veins to swell.
Once the puncture site is prepared, a needle is gently inserted into the vein.
Blood is drawn from the vein through the needle and into a vial or tube.
Once sufficient blood is collected, the elastic band is removed from the upper arm.
The needle is removed, and pressure is applied to the puncture site to reduce bruising and bleeding.
A blood draw is a relatively quick process, often taking less than three minutes. Patients may experience a brief prick or sting of pain when the needle is inserted and withdrawn.
After the test
Once the blood draw is finished, patients can remove the pressure placed on the puncture site after a minute or two. Bandages or gauze may also be used to prevent bleeding, which can be kept on for a few hours.
No additional restrictions on activities are required after a blood draw for an HIV viral load test.
FAQs About the HIV Viral Load Test
Should I get an HIV viral load test if I think I was recently exposed to HIV?
An HIV viral load test may be recommended if you believe you were exposed to HIV within the past few weeks or if you are experiencing symptoms of early HIV infection. Because this test detects the virus itself rather than antibodies, it may identify infection earlier than some other HIV tests. However, viral load testing is usually ordered after a high-risk exposure, symptoms of acute infection, or a positive result from another HIV test. A health care provider can help determine whether an HIV viral load test or another type of HIV test is most appropriate.
How will I receive my HIV viral load test results?
Results are typically available within 1 to 5 business days, depending on the laboratory performing the test. Results are usually provided by your health care provider, through your patient portal, or by the testing laboratory. If HIV RNA is detected in the blood sample, additional evaluation or confirmatory testing may be recommended before a diagnosis is finalized.
What do HIV viral load test results mean?
HIV viral load results show how many copies of HIV RNA are present in a milliliter of blood. Higher numbers indicate that the virus is actively replicating in the body. If the viral load is undetectable, it means the level of virus is too low for the test to measure. In people receiving treatment for HIV, an undetectable viral load is the goal because it indicates that treatment is effectively controlling the virus. A positive viral load test indicates you are at high risk of passing on HIV to a sexual partner.
What happens if my HIV viral load test is positive?
If HIV RNA is detected, a health care provider will review the result and may order additional tests to confirm the diagnosis and evaluate your health. If HIV infection is confirmed, treatment with antiretroviral therapy (ART) can begin. Modern HIV treatments are highly effective and can reduce the viral load to undetectable levels, allowing many people with HIV to live long and healthy lives.
If I test positive, what are the next steps?
After a confirmed HIV diagnosis, your health care provider will typically perform additional tests, including a CD4 count and baseline viral load, to help guide treatment. Antiretroviral therapy is usually started as soon as possible to control the virus and protect the immune system. Regular follow-up appointments and viral load testing are used to monitor treatment and ensure the virus remains suppressed.