Hiv / Aids Tests & Diagnosis | Apollo Diagnostic

HIV/AIDS (Acquired Immunodeficiency Syndrome)

AIDS is caused due to human immunodeficiency virus(HIV) infection. This retrovirus attacks the immune system, especially the CD4 cells(T- helper cells), which help to keep infections at bay. Therefore, AIDS patients are highly susceptible to infections and infection related cancers.

India has the third largest AIDS epidemic in the world. Around 2.1 million people in India are living with AIDS. In 2016, there had been nearly 62000 deaths due to HIV.

Transmission of HIV

HIV virus is transmitted when the blood of a healthy individual comes in contact with certain body fluids of an infected person such as blood, sexual fluids and breast milk. The following are the modes of transmission of HIV virus:

Having unprotected sex with an infected person.
Sharing injectable drugs with an infected person
Sharing needles during body piercing and tattooing.
Transmission from an infected mother to baby via breastfeeding
Using HIV infected blood for transfusion (Rare)

Staging and Symptoms of HIV

HIV infection typically progresses through three stages:

Stage 1: Acute HIV infection: (within 2-6 weeks of HIV infection) At this time, the patient is extremely contagious, but is often unaware that they are infected because they may not feel sick at all. However, a patient may experience minor flu like symptoms such as headache, diarrhea, nausea vomiting and fatigue.

Stage 2: Asymptomatic/ Chronic HIV infection: The infected person is completely asymptomatic in this period. The HIV is still active but is multiplying at a very slow rate. This phase may be as long as a decade for a patient who is not taking treatment for HIV. However, with treatment, a person would remain in this stage for several decades. The infection in this stage is still contagious. During the end of this phase, the infected person has speedily dropping levels of CD4 in blood and the amount of HIV in blood is also increasing steadily.

Stage 3: Acquired Immunodeficiency Syndrome (AIDS): It is the advanced stage of infection where the levels of CD4 drop below 200(Normal-500-1500). Common symptoms of AIDS include- chills, fever, sweats, swollen lymph glands, weakness, and weight loss. People who do not take any treatment for AIDS may survive for 3 years. This duration can be lesser if the patient contracts a dangerous infection.

Diagnosis of HIV

Most infected people do not have any symptoms and thus do not realize if they have HIV. Testing is the only means to check for HIV infection. If you develop flu like symptoms after a potential exposure to HIV, please take a test for HIV. HIV testing would help you to get treated timely and prevent transmission of disease.

There are three main types of tests to diagnose HIV:

Antibody test: This test detects the presence of HIV antibodies in blood or oral fluids. It detects HIV sooner than any other test. However, these antibodies can be produced only around 3- 12 weeks after infection.
Combination (Antigen/ Antibody) test: This test looks for both the HIV antigen and antibodies in blood. Antigens are the foreign substances that activate your immune system. Antibodies are produced by the immune system in response to infection. When you are infected with HIV, an antigen p-24 is produced much before the antibodies develop. It takes around 2 to 6 weeks for a combination test to detect HIV infection.
Nucleic Acid Tests: This test detects HIV virus in blood. This test can detect HIV infection as soon as 7-28 days after a person is infected with HIV. This test yields accurate results but is very expensive and not routinely done for HIV screening.

If HIV screening is positive, a follow up test is done to confirm diagnosis. A negative test may not necessarily mean that you do not have HIV infection. If the test is performed in the window period- the period between the time when the patient was infected and the time when the tests are able to detect the presence of HIV infection, the test would be negative. This window period may vary from patient to patient. In this case, you may be asked for a retesting after 3weeks.

Tests to plan the treatment

If you are HIV positive, you would be asked to take certain tests to find out the severity of disease and the drugs which may be beneficial to you. These tests include:

CD4 count: CD4 are the white blood cells that are specifically targeted and destroyed by the HIV virus. When your CD4 count is less than 200, it means that you have AIDS.
Viral Load: This test determines the amount of virus in blood.
Drug Resistance: This test would help to find out if the strain of HIV that has infected you would respond to the anti-HIV drug that is prescribed.

Treatment of HIV

There is no cure for HIV infection. However, if you are HIV positive, your physician would prescribe some drugs (antiretroviral drugs) that may curb disease progression.

Prevention of HIV infection

There is no specific vaccine to prevent HIV infection. However, certain measures could be taken to prevent the spread of HIV. They include:

Safe sex: Use a new condom everytime when you have sex. Water based lubricants should be preferred as oil based lubricants weaken the condom.
Avoid sharing needles: If you use needles to inject drugs make sure it is cleaned and sterilized properly before use. Never share the needle that has been already used once.
Consider male circumcision: Studies have proven that circumcision decreases the risk of HIV in males.
If you are HIV+ve: Please let your partner know so that they can get tested and receive appropriate medical care. Do not donate blood or other body tissues. Avoid sharing personal items such as toothbrushes and razors.
If you are HIV+ve and pregnant: Your baby is at high risk of acquiring HIV. Early and prompt treatment reduces the risk of infection in the baby. Avoid breastfeeding.