HIV Testing: Types of Tests and When to Get Tested

What Is an HIV Test?

HIV tests are done to rule out the presence of human immunodeficiency virus. This sexually transmitted infection affects a person's immune system and prevents the body from fighting against any disease. Diagnosing HIV infection at the earliest is very important.

HIV symptoms in men and women under proper treatment help to maintain an undetectable viral load that cannot transmit the disease to their sexual partners.

The only way to know the HIV status of a person is by getting tested. When done correctly and at the right time, HIV tests are accurate and dependable.

What Are the Three Tests Done for Diagnosing HIV?

To diagnose the HIV condition, these HIV tests can be recommended. Depending on which test is done, a blood sample or an oral fluid sample will be tested for the presence of HIV. Oral fluid is different from saliva; it contains cells in the mouth.

Common HIV tests:

• NAT (Nucleic Acid Test): This test can detect HIV RNA, the genetic material. It can also detect the virus load, that is, the amount of HIV present in the blood. The NAT test requires a blood sample and is expensive.

• Antigen or antibody test: To detect signs of HIV, a combination of antigen and antibody tests is performed. This test first determines the presence of an antigen, a substance that activates the immune system to fight infections. In the presence of HIV, the p24 antigen will be present in the blood, fighting against the infection. This test also tests for the presence of HIV antibodies.

• Antibody test: This test determines HIV antibodies that might be present in the blood or oral fluid samples. This is one of the most rapid tests; blood from the vein is used for early detection rather than oral fluid.

An antibody test is usually recommended for screening purposes. If symptoms of the infection occur, NAT is suggested, as it is expensive for the initial tests. If the infection is confirmed, doctors can recommend NAT to determine the virus load present.

When Would an HIV Test Be Needed?

It is recommended that everyone between the ages of 15 and 65 should take an HIV test at least once in their lifetime. Since HIV often causes no early symptoms, HIV tests detect infection before symptoms develop and help prevent the spread of the virus.

A person should also get tested when there is a high risk of HIV exposure or if a female is pregnant. HIV blood tests are usually done by taking blood from the vein using a small needle.

HIV testing in high-risk groups

HIV infections are generally transmitted through body fluids, which can be exchanged during sex and blood transfusion. The person is considered high risk if exposed to these fluids from an infected person. Having unprotected sex with an infected person increases the risk of spreading this infection.

Regular HIV infection tests are recommended if:

• The person had any form of sex with the infected person or with the person whose HIV status is not known.

• If the person has multiple sex partners or the partner has many sexual partners.

• If a male has sex with another male, then the chances are high.

• If the person has sexually transmitted infections other than HIV.

• If the person shares injection needles with an infected person.

HIV testing during pregnancy

HIV tests can be done during pregnancy, and they are usually performed in the first trimester. HIV infection can be transmitted from the mother to the fetus through breast milk.

Getting treated at the early stage of pregnancy can help prevent the infection from being transmitted from the mother to the baby.

How Soon After HIV Exposure Can a Test Detect the Virus?

HIV screening tests cannot detect HIV immediately after a person is exposed. It takes time for the body to make antibodies in response to the virus.

Every HIV test has a different window period, which is how long a person waits after exposure until they get an accurate result. No HIV test can confirm that the person carries the virus immediately after exposure. A person usually needs to get tested after the window period.

• The nucleic acid test (NAT) has a short window period. It can tell if a person has an HIV infection 10 to 33 days post-exposure.

• Antigen or antibody tests can diagnose infection after 18 to 45 days of exposure or 18 to 90 days of exposure.

• Antibody tests detect infection after 23 to 90 days of exposure.

Very early testing can provide false results, whereas waiting too long to get tested can result in missing out on early treatments, and the person can unknowingly spread the infection to others.

How Long Do HIV Test Results Take?

The type of test used depends on how quickly a person needs results. Rapid tests, such as antigen or antibody tests, can produce positive or negative HIV test results within 20 minutes.

How Does This HIV Test Work?

An HIV test looks for HIV in blood or oral fluid, along with HIV antigens and antibodies, or just antibodies. Additional testing, like HIV antibody tests, has to be done to confirm the results if the test is positive.

If the test is negative, this means that the person does not have the virus. To trust the results, one needs to be sure that they take the test at the right time to detect the virus. It takes some time after a person gets exposed to the virus for an HIV test to detect the HIV infection.

What Type of Results Do You Get, and What Do the Results Mean?

The test results will often be positive or negative. The negative result indicates that the test cannot detect any virus. These results also mean that the person does not have HIV, or it is very early on, taking the test after an HIV exposure.

The positive result means that the test detected the virus with HIV antibodies. These results indicate that the person is infected with HIV or needs additional testing to confirm the diagnosis.

What Should One Do if the Results Are Negative?

• Negative test results: In this case, the result of the test will be negative after testing for HIV, and the person can take preventive measures to protect themselves from HIV infection.

• False negative test results: It is also possible to get a false negative result where the test results show negative, but the person is infected.

What Should One Do if the Results Are Positive?

• Positive test result: A positive HIV test result indicates the presence of traces of HIV in the body when doing rapid HIV testing. If there is a confirmatory result, then the person needs to consult the physician for a further treatment plan. The healthcare provider will see how far the HIV has progressed, and accordingly, medicines are prescribed to manage HIV. Antiretroviral therapy (ART) helps to fight against HIV and prevent AIDS.

• False-positive test results: In rare cases, the test results may be false, where the test will show positive results of HIV, but the person may not be affected.

Conclusion

HIV testing is the only reliable way to know a person’s HIV status. Because HIV may not cause symptoms in its early stages, many people remain unaware they are infected and can unknowingly transmit the virus to others. Early HIV testing ensures timely diagnosis and treatment with antiretroviral therapy (ART). Thus preventing transmission.

If you have had possible exposure, belong to a high-risk group, or are pregnant, timely testing is essential. Consult an HIV specialist for guidance and to receive the proper test at the right time.

Key Takeaways

• HIV testing is the only way to confirm HIV infection, as early stages often show no symptoms.

• Early testing helps prevent the spread of HIV.

• HIV testing is essential because nearly 40% of HIV infections are spread by people who are unaware of their HIV status. This highlights why routine testing plays a key role in preventing transmission.