Introduction to HIV
Origin of HIV is mainly in non-primates and had spread to human beings through aeons. This disease was diagnosed in the 1980s for the first time and after its discovery, it has taken the lives of about 25 million people till date. The term HIV and AIDS are used simultaneously but actually, they are not interrelated. In reality, HIV is the form of virus which causes AIDS. These viruses cause adverse effects on the human immune system. HIV virus is a retrovirus and has RNA as their genetic material. HIV virus affects a particular type of blood cell, the WBC (White Blood Cells) and the T-helper cells and HIV virus also has a tendency to make copies of itself inside these cells. T-helper cells are also known as CD4 cells.
Ways Through Which HIV Infection Spreads
Some of the common ways by which HIV infection occurs are listed below:
1. One of the most common ways is through unprotected sexual interaction with an already infected person.
2. Use of a needle which was earlier used for an infected person.
3. Transfer of HIV virus through infected mother to the baby through the placenta.
4. If blood is transfused from an infected person.
5. HIV virus has a long incubation period before it starts to attack the immune system (10 years).
Types of HIV
Based on their strains HIV are of two types:
HIV - 1: HIV 1 is one of the most common types of virus that spread world wide.
HIV-2: This type of strain is mainly found in western Africa, with only a few cases in India and Europe.
There are 8 types of HIV-2 groups known to date i.e (A to H).
How HIV Infection Occurs?
In primary steps, HIV infects macrophages which are present in the blood. Once they complete infection in macrophages, the viral RNA enters the host cell and produces DNA inside the cell with the help of reverse transcription. This viral DNA then enters into the host genome and starts the production of multiple RNA copies and this production takes place through the transcription process. These RNAs then produce multiple copies of the virus and continue the infection throughout the body in the same way.
Simultaneously, HIV also enters into the T-lymphocytes and continues this process as it had done in macrophages. This process causes a decrease in the number of helper T lymphocytes. Due to this process, immunity of infected people keeps on decreasing. This loss in immunity causes infections, which are the major symptoms of AIDS. More symptoms of this disease are bouts of fever, diarrhoea and significant weight loss.
What is AIDS?
Disease caused by the HIV virus is known as AIDS or Acquired Immune Deficiency Syndrome. In this disease, a person’s immune system is affected so much that they become too weak to fight against any kind of infection or disease. AIDS is usually known as the last stage of HIV infection; a stage where the body can no longer defend itself and thus spawns various diseases. AIDS, when untreated, leads to death.
Symptoms of AIDS
The symptoms of HIV are not always the same; they differ from person to person. Some of the common signs are listed below:
Fever
Chills
Headache
Joint pains
Sore throat
Muscle aches
Upset stomach
Red rashes on the skin
Tiredness and weakness
Sweating during the night
Swollen or enlarged Glands
These symptoms often disappear in a few days or a few weeks. Mostly a person with HIV often experiences no symptoms and feels healthy like they usually feel.
Prevention of AIDS
By taking some prevention we can stop HIV from spreading. HIV infection can be diagnosed with the help of a test known as ELISA which stands for ‘Enzyme Linked Immuno Sorbent Assay’. As we all know that AIDS is an incurable disease, so far; thus, it’s prevention is the only thing which we can do.
Some of the preventive measures are listed below:
By using disposable needles
Practising safe sex, i.e., by using protection like condoms
Regular health check-ups
Monitoring during blood transfusion and pregnancy.
AIDS Awareness
One of the most important factors is the awareness of AIDS by organising seminars, camps, etc. As it does not spread by normal physical contact, so the infected persons should not be discriminated against and must be treated like normal persons.
FAQs on AIDS and HIV
1. What do the acronyms HIV and AIDS stand for?
HIV stands for Human Immunodeficiency Virus. It is the virus that attacks the body's immune system. AIDS stands for Acquired Immunodeficiency Syndrome, which is the final and most severe stage of an HIV infection, where the immune system is critically damaged and can no longer fight off infections.
2. What is the fundamental difference between being HIV-positive and having AIDS?
The fundamental difference is that HIV is the virus, while AIDS is the condition or syndrome it causes. A person can be HIV-positive for many years without developing AIDS. AIDS is the clinical diagnosis made when the HIV infection has severely weakened the immune system, leading to a very low count of specific immune cells (CD4 cells) and the onset of opportunistic infections.
3. What are the primary modes of transmission for the HIV virus?
HIV is transmitted through the exchange of specific bodily fluids from an infected person. The primary modes of transmission include:
- Engaging in unprotected sexual contact with an infected partner.
- Sharing contaminated needles, syringes, or other drug injection equipment.
- Receiving transfusions of contaminated blood or blood products.
- From an infected mother to her child during pregnancy, childbirth, or breastfeeding (vertical transmission).
4. Which diagnostic test is most commonly used to detect HIV infection?
The most common and widely used screening test to detect the presence of antibodies against HIV is the ELISA (Enzyme-Linked Immunosorbent Assay). A positive result from an ELISA test is typically confirmed with a more specific test, such as the Western Blot, to ensure an accurate diagnosis.
5. Why is HIV called a retrovirus, and how does this characteristic make it so difficult to treat?
HIV is classified as a retrovirus because it carries its genetic information as RNA, not DNA. Upon entering a host cell, it uses a unique enzyme called reverse transcriptase to convert its RNA into DNA. This new viral DNA is then integrated into the host cell's own DNA. This permanent integration into the host's genetic material makes the infection lifelong and extremely difficult to cure, as the cell is effectively hijacked to produce more viruses.
6. How does HIV specifically target and weaken the human immune system?
HIV specifically targets and destroys a crucial type of white blood cell known as the T-helper cell (also called CD4 cell). These cells are essential for orchestrating the body's immune response. The virus enters these cells, replicates itself, and destroys the cell in the process. Over time, the continuous destruction of T-helper cells leads to a severe drop in their numbers, crippling the immune system and leaving the body vulnerable to infections and cancers.
7. Why can a person with HIV remain asymptomatic for a long period, sometimes for many years?
After the initial infection, HIV enters a stage called the clinical latency period. During this phase, the virus is still actively replicating, but at very low levels. The body's immune system is strong enough to keep the virus largely under control, maintaining a relatively stable count of T-helper cells. Because the immune system is still functioning effectively, the person experiences no noticeable symptoms. This asymptomatic incubation period can last for 8 to 10 years or more before the immune system eventually weakens and symptoms of AIDS appear.
8. What are the major symptoms that appear when HIV progresses to full-blown AIDS?
When HIV infection advances to AIDS, the immune system is severely compromised, leading to opportunistic infections. The major signs and symptoms include:
- Significant and unexplained weight loss.
- Bouts of fever and drenching night sweats.
- Chronic diarrhoea lasting for several weeks.
- Extreme and persistent fatigue.
- Increased susceptibility to severe infections like tuberculosis and pneumonia.
9. Since there is no cure for AIDS, what are the most effective strategies for prevention as per the CBSE 2025-26 syllabus?
As per the CBSE 2025-26 syllabus, prevention is the most critical defence against AIDS. The key strategies are:
- Education and Awareness: Spreading correct information about HIV transmission and prevention through organisations like NACO (National AIDS Control Organisation).
- Safe Sexual Practices: Consistently using protection, such as condoms, during sexual intercourse.
- Blood Safety: Ensuring that all blood for transfusions is properly screened for HIV.
- Sterile Equipment: Always using fresh, disposable needles and syringes for injections.
10. Why is it that HIV does not spread through casual physical contact like hugging or sharing meals?
HIV is not transmitted through casual contact because the virus is fragile and cannot survive long outside the body. Furthermore, it is not present in sufficient quantities in saliva, sweat, or tears to cause an infection. Transmission requires a direct exchange of specific bodily fluids with a high viral load, such as blood, semen, or breast milk. Therefore, actions like hugging, shaking hands, sharing food, or using the same toilet pose no risk of spreading the virus.
