Acquired immunodeficiency syndrome (AIDS) is a severe, life-threatening condition caused by the human immunodeficiency virus (HIV). This virus specifically targets and weakens the immune system by destroying CD4 cells, which are crucial for defending the body against infections. As a result, individuals with AIDS become highly susceptible to opportunistic infections and certain cancers that a healthy immune system would normally resist.

HIV is transmitted through contact with certain bodily fluids from an infected person, including blood, semen, vaginal secretions, and breast milk. The primary modes of transmission include:

1. Unprotected Sexual Contact – HIV can spread through vaginal, anal, or oral sex if one partner is infected. The virus can enter the body through mucous membranes or small tears in the skin.

2. Sharing Contaminated Needles – Intravenous drug users who share needles or syringes are at high risk because HIV can be transmitted through traces of infected blood.

3. Mother-to-Child Transmission – An HIV-positive mother can pass the virus to her baby during pregnancy, childbirth, or breastfeeding. However, with proper medical care, the risk can be significantly reduced.

4. Blood Transfusions and Organ Transplants – Although rare in developed countries due to strict screening protocols, HIV can be transmitted through infected blood or organ donations if proper testing is not conducted.

HIV gradually weakens the immune system over time. Without treatment, the virus replicates and destroys CD4 cells, leading to a severely compromised immune system. AIDS is diagnosed when:

The CD4 cell count drops below 200 cells per cubic millimeter (normal range is 500–1,500).

The individual develops opportunistic infections or cancers associated with advanced HIV.

The symptoms vary depending on the stage of infection:

1. Acute HIV Infection (Primary Infection)

- Occurs 2–4 weeks after exposure.

- Flu-like symptoms such as fever, chills, sore throat, muscle aches, and swollen lymph nodes.

- Some people may mistake these symptoms for a common cold or flu.

2. Chronic HIV Infection (Clinical Latency Stage)

- The virus remains active but reproduces at low levels.

- Many people experience no symptoms or only mild swelling of lymph nodes.

- With antiretroviral therapy (ART), this stage can last for decades.

3. AIDS (Final Stage of HIV Infection)

- Severe immune system damage leads to frequent infections and illnesses.

- Symptoms include persistent fever, rapid weight loss, chronic diarrhea, extreme fatigue, night sweats, skin rashes, and oral thrush.

- Without treatment, life expectancy is significantly reduced.

While there is currently no cure for HIV, antiretroviral therapy (ART) can effectively control the virus, allowing people with HIV to live long, healthy lives. Modern treatments include:

• Long-acting HIV medications – Injectable formulations that reduce the need for daily pills.

• Single-tablet regimens (STRs) – Combination drugs that simplify treatment.

• Pre-exposure prophylaxis (PrEP) – Preventive medication for high-risk individuals.

Early diagnosis and treatment are crucial in preventing the progression to AIDS and reducing transmission risks. Regular testing, safe practices, and adherence to prescribed medications can help manage HIV effectively.