HIV

HIV infection is caused by the human immunodeficiency virus (HIV), which attacks and gradually weakens the body’s immune system. Specifically, the virus targets CD4 cells (T cells), which play a vital role in fighting off infections. Over time, the destruction of these cells makes it increasingly difficult for the body to defend itself against illnesses, leaving individuals vulnerable to infections and certain cancers.

If left untreated, HIV infection progresses through several stages, eventually leading to acquired immunodeficiency syndrome (AIDS), the most severe phase of the disease.

How HIV Affects the Body
HIV replicates within CD4 cells, destroying them in the process. The gradual loss of these immune cells has a cascading effect on the body’s ability to respond to pathogens. As the number of CD4 cells declines, the risk of opportunistic infections and certain cancers increases.

Stages of HIV Infection

1. Acute HIV Infection (Acute Retroviral Syndrome):
   • Occurs 2–4 weeks after initial exposure to the virus.
   • Symptoms may include fever, sore throat, swollen lymph nodes, rash, fatigue, and muscle aches, resembling a severe flu or mononucleosis.
   • This is the period when the virus multiplies rapidly, and individuals are highly infectious.
2. Asymptomatic HIV Infection (Clinical Latency Stage):
   • Following the acute phase, HIV enters a stage where it is active but reproduces at very low levels.
   • This phase can last several years without noticeable symptoms, but the virus continues to damage the immune system.
3. Early Symptomatic HIV Infection:
   • As the immune system weakens, symptoms such as persistent fever, fatigue, diarrhea, weight loss, and swollen lymph nodes may appear.
   • Recurrent infections, such as oral thrush or shingles, may also occur.
4. AIDS (Acquired Immunodeficiency Syndrome):
   • The most advanced stage of HIV infection, characterized by severe immune system damage.
   • CD4 cell count drops below 200 cells/mm³, or specific opportunistic infections or cancers are diagnosed, such as pneumocystis pneumonia (PCP), Kaposi’s sarcoma, or tuberculosis.

Transmission of HIV
HIV is transmitted through direct contact with certain body fluids from an infected person, including:

• Blood.
• Semen or pre-seminal fluid.
• Vaginal and rectal fluids.
• Breast milk.

Common modes of transmission include:

• Unprotected sexual contact with an infected partner.
• Sharing needles or syringes.
• From mother to child during pregnancy, childbirth, or breastfeeding (perinatal transmission).
• Blood transfusions or organ transplants (rare in countries with rigorous screening protocols).

HIV is not spread through casual contact, such as hugging, kissing, sharing food or drinks, insect bites, or touching surfaces.