UPDATE COMING We’re currently working to update this article. Studies have shown that a person living with HIV who is on regular antiretroviral therapy that reduces the virus to undetectable levels in the blood is NOT able to transmit HIV to a partner during sex. This page will be updated soon to reflect the medical consensus that “Undetectable = Untransmittable.”
According to the Centers for Disease Control and Prevention (CDC), roughly 1.2 million Americans are living with HIV. More than 12 percent of them don’t know they have it. In addition to not getting the treatment they need, they can unknowingly spread the virus to others. In fact, 30 percent of new HIV cases are transmitted by undiagnosed people.
The CDC’s recommendations for HIV testing advise healthcare professionals to provide routine screening for HIV as a part of standard care. But some providers aren’t implementing these guidelines. Many Americans have never been tested for HIV.
If you haven’t been tested for HIV, consider asking your doctor for an HIV test. You can also seek free and anonymous HIV testing at a clinic near you. Visit the CDC’s GetTested website to find a local testing site.
Who needs HIV/AIDS testing?
Routine HIV testing should be provided in all healthcare settings, advises the CDC. If you’re at high risk for HIV, you should be tested at least once a year. High-risk groups include people who have multiple sexual partners, people who engage in unprotected sex, people who engage in sex for money, people whose partners have HIV, and intravenous drug users.
You should also get tested for HIV:
- before you begin a new sexual relationship
- if you’ve learned that you’re pregnant
- if you have symptoms of another sexually transmitted infection (STI)
If you’ve contracted HIV, early detection and treatment can improve your outlook and lower your risk of developing AIDS. It can also reduce your risk of spreading the virus to other people.
If you know that you’ve been exposed to HIV, seek care as soon as possible. In some cases, your doctor may prescribe post-exposure prophylaxis. These medications may help reduce your chances of contracting HIV after you’ve been exposed to it.
What tests are used to diagnose HIV?
Your doctor can use a number of different tests to check for HIV infection. These tests can be performed on:
- blood samples (either in the office by having your finger pricked, or by going to the lab to have your blood drawn)
- saliva samples (obtained by swabbing inside your mouth)
Not all tests require a blood sample or doctor’s visit. In 2012, the U.S. Food and Drug Administration approved the first rapid test for HIV that can be performed at home.
If you’ve contracted HIV, it can take up to six months after you’ve been infected by the virus for a standard HIV antibody test to produce positive results. These tests detect antibodies to the HIV virus rather than the virus itself. Antibodies can take several months to develop in your body. As a result, early tests may come back negative, even if you’ve contracted the HIV virus.
If you know you’ve been exposed to HIV, tell your doctor. Alternative tests can be used to detect a recent infection.
What tests are used to monitor HIV?
If you’ve been diagnosed with HIV, it’s important to monitor your condition on an ongoing basis. Your doctor can use several tests to do this. The two most common measures for assessing HIV infection are CD4 count and viral load.
HIV targets and destroys CD4 cells, a type of white blood cell in your body. A healthy person has a CD4 count well above 500 cells per cubic millimeter (cells/mm3). If you contract HIV, this number may drop as the infection progresses. If you develop a CD4 count of less than 200 cells/mm3, your doctor will likely diagnose you with AIDS.
Early and effective treatment can help you maintain a healthy CD4 count and lower your chances of developing AIDS. If your treatment is working, your CD4 count should remain level or increase. Measuring your CD4 count is a good way for your doctor to assess how well your treatment is working. It’s also a good indicator of your overall immune function.
If your CD4 count drops below particular levels, your risk of developing certain diseases increases substantially. Based on your CD4 count, your doctor may recommend prophylactic antibiotics to help prevent certain infections.
Viral load is a measure of the amount of HIV virus in your blood. When your viral load is low, HIV is less likely to negatively affect your health. You’re also less likely to spread HIV to others when your viral load is low.
Your doctor can measure your viral load to monitor the effectiveness of your HIV treatment and the status of your disease. Effective treatment should reduce your viral load to undetectable levels. If you maintain an undetectable viral load, you’re unlikely to develop AIDS.
Your doctor may also order tests to learn if your strain of HIV is resistant to any medications used to treat the infection. This can help them decide which anti-HIV drug regimen is most appropriate for you.
Your doctor may also use other tests to monitor you for common complications of HIV or side effects of treatment. For example, they may perform regular tests to:
- monitor your liver function
- monitor your kidney function
- check for cardiovascular and metabolic changes
Your doctor may also perform physical exams and tests to check for other illness or infections associated with HIV or AIDS, such as other STIs, urinary tract infections, or tuberculosis. A CD4 count below 200 cells/mm3 isn’t the only sign that your HIV has progressed to AIDS. AIDS can also be defined by the presence of certain opportunistic illnesses or infections, including:
- fungal diseases, such as coccidioidomycosis, cryptococcosis, or cryptosporidiosis
- candidiasis, or yeast infection, in your bronchi, trachea, or lungs
- histoplasmosis, a type of lung infection
- Pneumocystis jiroveci pneumonia (previously known as Pneumocystis carinii pneumonia or PCP)
- recurrent pneumonia
- Mycobacterium avium complex, a bacterial infection
- chronic herpes simplex ulcers, lasting longer than one month
- isosporiasis, an intestinal disease
- recurrent Salmonella septicemia
- toxoplasmosis, a parasitic infection of your brain
- progressive multifocal leukoencephalopathy (PML), a brain disease
- invasive cervical cancer
- Kaposi's sarcoma (KS)
- wasting syndrome, or extreme weight loss
If you’ve been diagnosed with HIV, it’s important to monitor your health closely and report any changes to your doctor. New symptoms may be a sign of an opportunistic infection or illness. In some cases, it may be a sign that your HIV treatment isn’t working properly or that your condition has progressed to AIDS. Early diagnosis and effective treatment can improve your outlook with HIV and lower your risk of developing AIDS.