I. Introduction

Without treatment, HIV can develop into acquired immunodeficiency syndrome or AIDS. In people with AIDS, the immune system is severely damaged, increasing the risk of opportunistic infections. Once HIV progresses to AIDS, life expectancy is usually around three years, although it’s only about one year once an opportunistic infection develops. In 2018, 37.9 million people were living with HIV or AIDS. The U.S. Department of Health and Human Services estimates that 1.7 million people acquired new HIV infections during the same year.

This guide provides an overview of the HIV test, including why it’s done and how the results are interpreted. It also lists the symptoms of HIV, discusses some of the risk factors, and explains the treatment options available for HIV.

II. Overview of the HIV Test

Why should I get tested?

The HIV test is the only way to know for sure if someone is infected with HIV. Getting tested is important because early detection of HIV tends to lead to better outcomes; for example, someone diagnosed with HIV can start taking antiretroviral drugs right away, which can reduce the risk that HIV will progress to AIDS. Early treatment can also lower the risk of transmitting HIV to another person. The results of an HIV test can also help infected individuals protect others from getting it. For example, if a pregnant woman knows she has HIV, she can take steps to reduce the risk of passing it to her baby.

When should I get tested?

The CDC recommends that everyone should have at least one HIV test at some point between the ages of 13 and 64. This recommendation applies to all individuals, not just those who have a higher risk of contracting HIV. According to CDC guidelines, individuals who do any of the following should have an HIV test every year:

  • Have sex with someone who has HIV
  • Use injectable drugs
  • Share needles with someone who has HIV
  • Have sex with a partner who has not disclosed his or her sexual history
  • Engage in male-to-male sexual intercourse

Yearly tests are also recommended for anyone who has been diagnosed with another sexually transmitted infection, people who have been diagnosed with or received treatment for tuberculosis or hepatitis, and those who trade sex for money or drugs.

What is required for the test?

HIV testing usually requires a blood sample, but HIV antibody tests can also be performed on a saliva sample.

How do I prepare for the test?

No special preparation is required for the HIV test.

III. The Basics of HIV

In a healthy person, the immune system uses several types of white blood cells to identify and fight harmful organisms. For example, B cells produce antibodies, which identify bacteria, viruses, and other foreign invaders. HIV weakens the immune system by destroying white blood cells. As a result, an individual with HIV is more susceptible to infections and certain types of cancer.

HIV is found in blood, semen, pre-seminal fluid, breast milk, and fluids present in the rectum and vagina. In the United States, the virus is typically transmitted by having sexual contact with an infected person or by sharing needles and other types of drug paraphernalia with someone who has HIV. In rare cases, health care workers contract HIV from needle-stick injuries, which occur when a needle, scalpel, or other sharp instrument that has been used on an infected patient accidentally pierces the skin of a doctor, nurse, or other health care provider.

Some individuals have a higher risk of developing HIV than others. For example, men and women who engage in anal sex have a higher risk of contracting HIV than people who engage in oral or penile-vaginal sex. The heightened risk is due to the fact that the rectum has a thin lining, which makes it more likely that HIV will be able to enter the body. Drug users are also more likely to contract HIV than non-users for two reasons. First, HIV can be transmitted from one user to another via needle sharing. Second, drugs typically lower inhibitions, making it less likely that an individual will use a condom or dental dam. Engaging in high-risk sexual behavior also increases the risk of HIV transmission. High-risk sexual behaviors include not using condoms, using a condom inconsistently, and having multiple sexual partners.

The signs and symptoms of HIV are subtle at first and may be attributed to the flu or another illness. Swollen glands are usually one of the first signs to appear. Within two to four weeks of contracting HIV, an individual typically experiences other flu-like symptoms, including fever, night sweats, sore throat, rash, muscle aches, mouth ulcers, chills, and fatigue. Not everyone experiences all of these symptoms, and some people with HIV do not have any symptoms at all during this initial stage.

During the second stage of HIV, known as the clinical latency stage, the virus continues to multiply; however, an individual in this stage of infection may not have any symptoms. Stage 3 occurs when the immune system is so weak that HIV progresses to AIDs. An individual with AIDS might experience chronic diarrhea, extreme fatigue, rapid weight loss, heavy sweating at night, memory loss, anal or genital sores, recurring fever, or blotches on the skin. During this stage, the individual may also develop pneumonia, yeast infections, cytomegalovirus, invasive cervical cancer, tuberculosis, or another opportunistic infection.

IV. How an HIV Test Works

Three types of tests can be used to determine if an individual has HIV. Antigen/antibody tests check for the presence of HIV antibodies and an antigen called p24. Antigen/antibody tests are useful for early diagnosis of HIV because p24 can be detected before HIV antibodies start to develop. Nucleic acid tests (NAT) are used to detect the HIV virus in an individual’s blood. Antibody tests check for HIV antibodies, but they don’t detect the p24 antigen. All three types of tests can be performed on a blood sample; HIV antibody testing can also be performed on a saliva sample. NAT is the least common test method, as it’s much more expensive than antibody or antigen/antibody testing.

In the United States, self-testing kits are available for individuals who are unwilling or unable to visit a testing facility. A self-test kit makes it possible for an individual to collect his or her own saliva sample and test it in a familiar, comfortable environment. The FDA-approved test kit provides results in 20 to 40 minutes. If the self-test is positive, the individual must have a confirmatory test performed in a laboratory. In some cases, the self-test could produce a false negative, which means the test result is negative even though the individual has been infected with HIV. This is more likely if the individual recently acquired the HIV infection.

V. Treatment for HIV

Antiretroviral therapy is a mainstay of HIV treatment. Although HIV can’t be cured, antiretroviral therapy can reduce an individual’s viral load. The lower the viral load, the lower the risk of transmitting HIV to another person. A reduced viral load also improves the immune system’s ability to fight off infections and certain types of cancer.

Several types of medications are used to treat HIV. Protease inhibitors, non-nucleoside reverse transcriptase inhibitors, integrase inhibitors, and nucleoside reverse transcriptase inhibitors prevent the HIV virus from multiplying. They do this by changing or blocking the enzymes involved in the replication process. CCR5 antagonists, fusion inhibitors, and post-attachment inhibitors make it more difficult for the HIV virus to affect CD4 cells, which are cells involved in the immune response. CCR5 antagonists and post-attachment inhibitors work by blocking certain molecules on the CD4 cells; by blocking these molecules, these medications prevent the HIV virus from entering the cells. Fusion inhibitors also prevent the HIV virus from entering CD4 cells. Some people with HIV also take pharmacokinetic enhancers, which are medications that make HIV medications more effective.

It’s extremely important for individuals with HIV to be monitored closely by their health care providers, even if their viral loads are low or they aren’t having any symptoms. Regular visits to a medical professional make it possible to identify complications early and make sure the individual’s treatment regimen is working as intended. Although antiretroviral therapy is effective, it can produce serious side effects, including nausea, vomiting, difficulty sleeping, and fatigue. The side effects of HIV medications may be more severe in individuals who have diabetes, heart disease, or other chronic health problems. Some HIV medications may also cause long-term side effects; for example, certain medicines can cause high cholesterol, a condition that increases the risk that an individual will develop heart disease.

If HIV progresses to AIDS, an individual may also need to be treated for opportunistic infections. The treatment regimen depends on the type of infection and the individual’s medical history. Bacterial infections are treated with antibiotics; viral infections are treated with antiviral medications; and fungal infections are treated with antifungals. Invasive cervical cancer and some types of lymphoma are also considered opportunistic infections. These conditions may be treated with chemotherapy, radiation therapy, surgery, or other cancer treatments.

VI. FAQs

Are home test kits accurate?

OraQuick, the only home HIV test approved by the U.S. Food & Drug Administration, has a test sensitivity of approximately 92%. This means it produces a positive result in 92% of people who have the HIV virus. OraQuick produces one false negative for every 12 tests performed on HIV-positive individuals. This means the test is negative even though the person has the HIV virus. OraQuick can also produce false positives, although they’re much rarer than false negatives, affecting only one out of every 5,000 uninfected individuals.

What should I do if my HIV test is positive?

An individual who receives a positive HIV test result should have another test right away. The second test is used to confirm the presence of HIV in the blood. If the second test is also positive, the individual should schedule an appointment with a healthcare professional as soon as possible. Starting antiretroviral therapy right away can prevent HIV from getting worse, and it can also reduce the risk that an infected individual will transmit it to someone else.

My HIV test was negative. Does that mean I definitely don't have HIV?

No. Once an individual is infected with the HIV virus, it takes some time for the immune system to start producing HIV antibodies. If an antibody test or antigen/antibody test is performed soon after exposure, the test result may be negative even though the HIV virus is present in the individual’s body.

Can I get HIV if someone bites me or spits on me?

HIV is not transmitted via spitting. The risk of transmission via biting is negligible. Although there have been a few reports of HIV being transmitted this way, researchers believe that the biters must have had blood in their mouths, and the people bitten must have had open wounds or other breaks in the skin that allowed the HIV virus to enter their bodies.

I think I was exposed to HIV. Should I wait to get tested?

The immune system doesn’t produce HIV antibodies right away, so getting tested a day or two after possible exposure may result in a false-negative result. According to the U.S. Department of Veterans Affairs, it’s wise to get tested within two to four weeks of possible exposure, get tested again three months later, and get a third test six months after the possible exposure. Most people who have HIV will test positive within one month of exposure; the rest will test positive within six months.

How does HIV spread from a pregnant woman to her baby?

Pregnant women can spread HIV to their babies in two ways. When the fetus is still developing inside the mother’s womb, the HIV virus can cross the placenta, infecting the fetus. During the birthing process, the baby can also come into contact with its mother’s blood and other body fluids, increasing the risk of transmission. It’s also possible for a nursing mother to transmit HIV to her baby via breast milk.

VII. Additional Resources

NameWebsiteSummary
AIDSinfoaidsinfo.nih.govThe U.S. Department of Health and Human Services has a library of resources on HIV prevention and treatment.
Centers for Disease Control and Preventionwww.cdc.govThe CDC offers a variety of resources related to HIV and AIDS.
National Institutes of Healthwww.nih.govLearn more about the advances that have been made in HIV and AIDS research.
HIV.govwww.hiv.govUse HIV.gov to find more information on HIV testing and treatment.
UNAIDSwww.unaids.org/enLearn more about UNAIDS’ efforts to deliver lifesaving HIV services where they’re needed most.

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