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HIV Testing and Its Prevention

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Human immunodeficiency virus (HIV) testing signifies whether a person got infected with HIV. A person between 13 to 64 years of age must include an HIV test as a routine exam.

Written by

Dr. Shuchi Jain

Medically reviewed by

Dr. Shah Sushma Kant

Published At October 26, 2022
Reviewed AtApril 13, 2024


The human immunodeficiency virus causes HIV infection that ultimately advances to acquired immunodeficiency syndrome (AIDS). The virus attacks the infection-fighting cells and weakens the immune system. The individuals become susceptible to even minor infections. The transmission is through body fluids (mostly). Various tests detect HIV, such as antigen tests, antigen-antibody tests, nucleic acid tests, etc. It can be prevented by adopting behavioral and biomedical approaches.

What Is HIV?

HIV is a human immunodeficiency virus that causes HIV infection wherein the body’s immune cells are at target. This virus attacks and destroys the T-cells (infection-fighting cells). A decrease in the number of clusters of differentiation four cells (T-cells) disables the body to fight off infection, thereby making it more prone to infection. Untreated HIV infection ultimately leads to AIDS.

What Is AIDS?

The advanced stage of HIV infection is AIDS. The term AIDS indicates;

  • Acquired - acquired or obtained from someone else.

  • Immunodeficiency - Weakening of the immune system.

  • Syndrome - A group of signs and symptoms associated with a disease.

How Is HIV Transmitted?

Contact with HIV-infected body fluids leads to its transmission. The fluids include:

  • Blood (sharing needles and syringes).

  • Semen (anal or vaginal sex without precautions).

  • Pre-seminal fluid.

  • Vaginal fluid.

  • Rectal fluid.

  • Breast milk (breastfeeding).

HIV does not spread by air, water, shaking hands, hugging, or sharing objects such as dishes, toilet seats, etc.

What Are the Symptoms of HIV and AIDS?

As soon as an individual encounter HIV infection, some may fall sick (acute HIV infection). The symptoms are primarily flu-like (fever, chill, rash) that last for a few days to weeks (two to four weeks).

The multiplication rate of the virus is rapid during the initial stage, after which it slows down.

AIDS occurs when the HIV infection is left untreated for many years (ten years or so). The immune system is at harm to a greater extent and the chances of opportunistic infections increase. Some people may not have the signs and symptoms but still, have HIV.

What Are the Various HIV Tests?

HIV tests are very accurate tests. But immediate exposure can never be diagnosed.

Depending on the types of tests, the efficiency for determining the exposure to the virus varies.

The three types of HIV tests include:

1. Antibody Test - This test detects HIV in oral or body fluids. It detects the virus after 23 to 90 days of exposure. For antibody tests, blood is collected from either a finger prick or a vein. However, blood taken from a vein can detect HIV sooner than a finger prick or oral fluid. Antibodies test includes - Rapid tests and food and drug administration-approved self-HIV tests.

2. Antigen-Antibody Test - As the name suggests, this test detects both HIV antigen and antibody. Antigens are foreign bodies that activate the immune system. The body produces antibodies in response to it. In the case of HIV, the p24 antigen is produced in the body. Antigen-antibody tests are lab tests. The blood is drawn from a vein. It detects the infection after 18 days to 45 days. Rapid antigen-antibody test: It is done by collecting blood with a finger prick. This test takes a long time to detect HIV, 18 days to 90 days after exposure.

3. Nucleic Acid Test (NAT) - It is a highly efficient test with greater accuracy. Since it is costly, it is not routinely done. It is advised in people with high-risk exposure. This test detects the infection after ten days to thirty-three days of exposure. The first two are routine tests, whereas a nucleic acid test is recommended in patients at higher risk. Depending upon the window period (the time between the exposure of HIV and its detection in the body), the tests are recommended. Initially, an antibody or antigen-antibody test is done. Depending upon the type of test, the follow-up tests are planned. If the initial test is a rapid test and if it is positive, then one must consult a doctor for follow-ups. If the initial test is a laboratory one, and if found positive, the lab will conduct the follow-up test on the same blood sample that was given during the initial test. The HIV tests are very accurate, and follow-up tests are done for surety.

4. Enzyme-Linked Immunosorbent Assay (ELISA) - It is a common laboratory test to measure the concentration of antibodies or antigens in a solution. There are different generations of ELISA. The first generation uses lysed (dead) viral cells as antigens, and the third generation uses synthetic peptides as antigens. The fourth generation is the newer generation of ELISA that helps in the simultaneous detection of HIV antigens and antibodies, while the other generations only measured antibodies.

5. Chemiluminescence Microparticle Immunoassay (CMIA) Test- It is a useful test that helps in the qualitative identification of HIV p24 antigens. It is similar to the p24 test and checks for both antigen and antibodies.

Why Is HIV Testing Important?

To know if one is HIV positive or not HIV test is required. An HIV-negative report indicates the absence of infection. Reports indicating a higher risk of HIV should follow pre-exposure prophylaxis. An HIV-positive report indicates the presence of HIV infection. One should not get scared or depressed and immediately consult a health care practitioner. Antiretroviral therapy is the key to treating this infection.

Who Should Get Tested for HIV?

  • Once in a Lifetime: A person ranging from 13 to 64 years of age should undergo a test once.

  • Once in a Year: At higher risk, one should get their tests done yearly.

  • Pregnant Woman: All pregnant women should undergo tests. If reports are positive, treatment for both mother and child is advised.

How Is AIDS Diagnosed?

When an HIV person suffers from weakness, weight loss, and fever, there are chances that HIV might have progressed to AIDS. But this is not the only criteria for diagnosing it.

There exist specific diagnostic criteria that include:

  • Low CD4 count (below 200 cells/mm3).

  • Presence of opportunistic infection.

How to Reduce the Risk of HIV?

There are two prevention strategies -

1. Behavioral.

2. Biomedical.

Behavioral strategies include:

  • Using condoms. Individuals have the option to purchase condoms for their own safety.

  • Safer sex.

  • Prohibiting needle or syringe exchange.

Biomedical strategies include:

  • Pre-exposure Prophylaxis (PrEP).

  • Post-exposure Prophylaxis (PEP).

How to Prevent HIV From Sex?

  • Using condoms the right way is the safest way to prevent HIV transmission.

  • Choose sex that is less risky than anal or vaginal sex.

  • Opt for pre-exposure prophylaxis is efficacious for preventing HIV from sex if taken as prescribed.

  • Not having sex is an effective way to prevent HIV transmission from sex.

  • If your partner is HIV positive, encourage them to take medicines, and once the viral load is undetectable, they can no longer transmit the infection.

How to Prevent HIV From Injections and Needles?

  • Use new, clean syringes every time.

  • Dispose of the needles after use.

  • Avoid injecting drugs.

How to Protect Others if You Have HIV?

  • Get in touch with a doctor and take ART.

  • Through ART, the viral load gets controlled within six months.

Once the viral load is undetectable, the person can no longer transmit the infection.

What Is PREP?

  • Pre-exposure prophylaxis (PrEP) is administered to people who do not have HIV but are at higher risk of HIV infection.

  • It includes daily intake of antiretroviral medication (ART).

  • It is a highly effective method (99%) but should not substitute the preventive measures.

What Is PEP?

  • Post-exposure prophylaxis (PEP), as the name suggests, is given just after the HIV exposure, no later than three days (72 hours). It is prescribed in an emergency situation.

  • It also includes a 28-day antiretroviral course.

What Is Perinatal Transmission of HIV?

The transmission of HIV from mother to child is called perinatal transmission.

It can occur during:

  • Pregnancy.

  • Labor or delivery.

  • Breastfeeding.

.Preventive measures during pregnancy and childbirth -

  • Early detection of HIV is a must in the expected mother.

  • HIV medicines are advised to both mother and infant to prevent transmission.

  • Avoid breastfeeding and substitute it with infant milk formula.

How Is HIV Treated or Prevented?

HIV medicines, also known as antiretroviral medicines, are used in treating HIV. These are the combination drugs taken routinely.

What Does Antiretroviral Therapy Do?

Antiretroviral therapy acts on multiplying HIV, thereby reducing the viral load to undetectable levels. It manages the illness by preventing the further progression of HIV and AIDS.

Why Should an HIV-Positive Take ART?

ART is particularly effective in reducing the viral load, thereby lowering the risk of transmission of HIV to a non-HIV partner. Hence, HIV medicines help the infected person live a longer, healthier, and better life. It is therefore rightly said - treatment is prevention (TasP).


As HIV advances, it leads to AIDS. But treatment is possible at any stage. Proper administration of antiretroviral therapy enables an individual to live a healthy and better life. Early detection and treatment are the keys to preventing its spread. One must be aware of treatment modalities and should also contribute to society by spreading awareness.

Remember: Progression of the disease can be taken care of at any stage. Thus one should not feel demotivated or anxious and opt for proper health care measures.

Frequently Asked Questions


How Long Does It Take To Detect HIV?

HIV (human immunodeficiency deficiency) can usually be detected within 18 to 90 days after exposure by a rapid antigen or antibody test, which is done by taking blood from a finger stick. An antigen or antibody lab test using blood from a vein can generally detect HIV within 18 to 45 days after exposure. A nucleic acid test (NAT) can generally detect HIV within 10 to 33 days after exposure.


What Test Is Done First in HIV Testing?

The primary test done to test HIV is generally an antigen or antibody test. If the initial HIV test is rapid or done by self-testing and if it comes positive, the person should immediately consult the doctor for follow-up testing.


What Is HIV 1 and 2 Test Called?

If a person is found positive for HIV, the Centers for drug research (CDC) recommends the HIV-1/HIV-2 antibody differentiation immunoassay. This is the confirmatory test for the presence of HIV and determines whether a person has HIV-1 or HIV-2.


What Is the Pill Used for the Prevention of HIV?

The pill used for the prevention of HIV is Pre-exposure prophylaxis (or PrEP). It slows downs the risk of acquiring HIV from sex by about 99 % and from injection drug use by around 74 %.


Why Is It Important to Prevent HIV?

It is important to prevent HIV as there is no proper cure for this infection. Prevention of HIV can be done by having protected intercourse, reducing the number of partners, avoiding the use of drug injections, etc.


Who Is at a Higher Risk of Getting HIV?

The higher risks for HIV can be seen in:
- People who have unprotected sex.
- People have a partner with HIV.
- People with a previous partner who had HIV.
- People who belong to an area with high HIV rates.
- People who share drug injections.


Can HIV Be Prevented or Cured?

There is no definitive cure for HIV but can be controlled by the treatment. The treatment can reduce the amount of HIV in the body and helps in staying healthy. The effect of the HIV virus can be reduced within six months in many people.


What Happens if ART Is Stopped for HIV?

ART is the anti-retroviral therapy that is important for the treatment of HIV. If ART is discontinued, it can result in the reproduction of the virus and circulation in the blood. This can increase inflammation and possibly result in a heart attack or other kidney or liver problems.


How Long Does ART Take To Work?

The ART works by stopping the CD4 cells from making more HIV. Viral load can be reduced by 90 % within the first few days and by around 99 % within the first few weeks. Virus continuously decreases within a few months.


What Are the Side Effects of ART?

The possible side effects of ART include:
- Headache.
- Nausea and vomiting.
- Diarrhea.
- Fatigue.
- Difficulty sleeping.
- Dry mouth.
- Rash.
- Dizziness.


Does Art Boost the Immune System?

HIV affects the immune system by infecting the CD4 cells and white blood cells, which help in fighting against infections and protect the body from disease. As CD4 cells start to die, the immune system gets weakened. Taking anti-HIV drugs slows down the ability of the virus to multiply and kill CD4 cells.


Does Art Restore Immune Function?

ART seems to restore immune function. Still, the virus continues to make the immune system weak in many ways, even in people in whom the virus remains undetected.
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Dr. Shah Sushma Kant
Dr. Shah Sushma Kant

HIV/AIDS specialist


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