How Soon Can HIV Be Detected in Blood?
Human immunodeficiency virus, better known as HIV, is a virus that attacks the body’s immune system. It is usually contracted through contact with bodily fluids such a blood, semen and vaginal fluids. It can be transmitted through sexual contact or by sharing needles with an HIV-infected person. HIV cannot be spread by saliva or touching someone with HIV. If left untreated, HIV can lead to the development of AIDS (acquired immunodeficiency syndrome), which is the most severe stage of HIV.
What tests are available for HIV?
The only way to know for sure whether you have HIV is to get tested. The CDC recommends anyone ages 13-64 be tested at least once a year and with any new sexual partner.
There are three types of tests available to check for HIV:
- A nucleic acid test is a blood test that looks for the virus in the blood. After blood is drawn from a vein and sent to a lab, the blood is tested to see if a person has HIV and see how much of the virus is present, which is known as HIV viral load. Results may take several days to be available.
- Antigen/antibody testing looks for both HIV antigens and antibodies present in the body. Antigens are foreign objects in your body that cause your immune system to activate and create antibodies, which are proteins that the body’s immune system creates to fight off infections, like HIV. For people who have HIV, an antigen called p24 is produced first, which then causes their immune system to create antibodies. Your healthcare provider can check for antigens and antibodies by drawing blood from a vein, which is then sent to a lab for testing. Results may take several days to be available. There are also rapid tests available that involve a finger prick, and results can be given in 30 minutes or less.
- Antibody tests only look for antibodies present in someone’s blood or saliva. Your healthcare provider can check for antibodies by drawing blood from a vein, which is then sent to a lab for testing. These test results may take several days to be available. For rapid results, they can perform a finger prick or take a swab of oral fluid, and results are available within 30 minutes.
Ochsner Health has partnered with Gilead Sciences to provide HIV and hepatitis C testing for any patient that is seen in the Emergency Department at the Baton Rouge, Iberville, Baptist and Jefferson Highway campuses. Multiple other Ochsner campuses are currently in the process of being approved for the grant.
Knowing your HIV status gives you powerful information to take the appropriate steps to keep yourself and your sexual partners safe.
There are multiple options available to the public that can decrease and possibly eliminate the risk of HIV transmission to themselves.
- Getting tested yearly and with every new sexual partner
- Condom use
- Use of PEP or "post exposure prophylaxis" for those with a possible exposure. PEP must be taken within 72 hours of exposure
- Use of PrEP or "pre exposure prophylaxis"
What is PrEP?
PrEP, or pre-exposure prophylaxis, is a medication taken daily by HIV-negative people who are at higher risk of transmission either through IV drug abuse or high-risk sexual behaviors.
There are two medications that are FDA approved for PrEP.
PrEP when taken daily has been proven to be 90% effective in preventing HIV transmission. PrEP is only available by prescription. If you believe PrEP is right for you, visit your healthcare provider to discuss options.
If you would like further information on the PrEP services Ochsner provides, please visit https://www.ochsner.org/services/prep
How soon after exposure does HIV show up in the tests?
After someone has had potential exposure to HIV, there is a window of time when it will show up on your test. This window can be anywhere from 10 days to three months. In general, tests that draw blood from a vein can typically detect HIV in the blood sooner:
- A nucleic acid test can detect HIV the soonest. This test can typically tell if someone has HIV 10 to 33 days after your potential exposure. This type of testing can be costly, so it is typically only offered to people who think they have had a high-risk exposure or are displaying symptoms of HIV.
- An antigen/antibody test performed by drawing blood from the vein and sending it off to a lab can typically tell if someone has HIV 18 to 45 days after exposure. The rapid antigen/antibody test done through finger prick can take longer to detect HIV, with most taking 18 to 90 days to detect HIV.
- An antibody test can take anywhere from 23 to 90 days to detect HIV after exposure. Antibody tests performed by drawing blood from the vein typically detecting HIV sooner.
There are cases where someone may get tested for HIV within the window of time, and their test results come back negative when they are, in fact, HIV-positive. Transmission during this period may be more likely because the virus levels within the body tend to be higher during this window period. If you get tested for HIV after potential exposure, and your results come back negative, it is essential that you get tested again if you are still within the window period. You can only be sure you are HIV-negative if your most recent test after the window period is negative and if you haven’t had potential exposure to HIV during the window period.
If you believe you were exposed to HIV through sex without a condom or due to a broken condom, it is essential that you make an appointment with your healthcare provider as soon as possible. In some cases, you may be able to reduce your risk of contracting HIV through the use of post-exposure prophylaxis (PEP), which is a medicine to prevent HIV after a possible exposure. PEP should be used only in emergency situations and must be started within 72 hours after recent potential exposure to HIV.
For those Individuals that have a positive HIV test, there are a multitude of options for treatment that have been developed. The mainstay of treatment for HIV is antiretroviral medications , which help control the growth of the virus. Over the past thirty years, we have been able to develop medications that allow for HIV positive patients to have undetectable levels of HIV viral load. And scientific evidence has confirmed that individuals who are at an undetectable range are no longer able to transmit the virus to other persons. In essence Undetectable = Untransmittable or U=U. By taking antiretroviral medication daily as prescribed, HIV cannot be sexually transmitted. Thus, the use of antiretroviral medication is a powerful tool in combating HIV.
Every single one of us is deserving of world-class healthcare delivered in a safe and welcoming environment. Ochsner is relentless when it comes to providing comprehensive, respectful care to all patients, regardless of sexual orientation or gender identity.
Schedule an appointment with one of our experts: https://www.ochsner.org/services/lgbtq-health-care.
If you would like to learn more about HIV, visit https://www.hiv.gov/
Editor's note: This blog was originally published on Feb. 10, 2021, and has since been updated.