HIV and AIDS

Definition: Human Immunodeficiency Virus (HIV) is a virus that attacks the immune system, specifically targeting CD4 cells (T cells), which play a crucial role in defending the body against infections.
Transmission: HIV is primarily transmitted through blood and body fluids, including:
  - Blood
  - Semen
  - Vaginal secretions
  - Less commonly through breast milk and amniotic fluid
Primary Risk: Sharing needles is one of the most significant transmission routes for HIV.

Definition of Viral Load: Viral load refers to the amount of HIV present in the blood. A higher viral load increases the risk of transmission.
Acute Phase (Initial Infection):
- Upon initial infection (Day 1), the viral load is very high as the virus begins to replicate rapidly in the host's body.
- Immune Response: B cells (plasma cells) start producing antibodies to combat the virus.
Antibody Development:
- It takes time (typically 2-4 weeks) for the body to develop enough antibodies for detection in standard tests.
- During this period, the individual may exhibit flu-like symptoms (e.g., fever, night sweats, muscle aches) but may test negative for HIV, indicating a "window period."

ELISA (Enzyme-Linked Immunosorbent Assay):
  - Purpose: Screens for antibodies against HIV.
  - Limitations:
    - False negatives can occur if tested during the acute phase before antibodies are sufficiently developed.
    - A negative result does not rule out HIV if the test occurs during the window period.
Western Blot Test:
- Used to confirm a positive ELISA result by detecting specific HIV antibodies.
Viral Load Test:
- Measures the amount of HIV in the blood and is crucial for treatment monitoring.
- Important for determining how well the body is responding to treatment.

False Negatives: Occur when the test returns a negative result despite an active HIV infection, typically within the window period.
False Positives: Occur when the test indicates HIV due to high antibodies from other sources (e.g., hepatitis, malaria, etc.), not necessarily related to HIV infection.

Key Definitions:
  - HIV: A virus that can lead to AIDS if untreated.
  - AIDS (Acquired Immunodeficiency Syndrome):
    - Diagnosed when CD4 count falls below 200 cells/mm³ or when the patient experiences opportunistic infections.
    - Everyone with AIDS has HIV, but not everyone with HIV has AIDS.
CD4 Cell Count:
- Healthy ranges are typically above 500 cells/mm³; below 200 cells/mm³ indicates severe immunosuppression and an AIDS diagnosis.
Symptoms of AIDS:
- Common opportunistic infections (e.g., pneumocystis pneumonia, herpes infections, Kaposi's sarcoma).
Progression Timeline: It can take 10 or more years for the progression to AIDS if left untreated, especially without antiretroviral therapy (ART).

Key Messages: Prevent spread of HIV through education:
  - ABCs for Prevention:
    - A: Abstinence
    - B: Be faithful
    - C: Condoms
  - Acknowledge the high risk of transmission through blood and semen.

Antiretroviral Therapy (ART):
- Stands for Highly Active Antiretroviral Therapy (HAART).
- Aims to reduce viral load, improve immune function (CD4 counts), and prevent progression to AIDS.
Mechanism: Suppresses viral replication without curing HIV.
Importance of Adherence:
- Missing doses can lead to drug resistance, making the treatment less effective.
- Education is crucial for ensuring adherence to prescribed regimens.

Window Period: Understanding critical for accurate diagnosis and treatment.
- Symptoms may mimic other viral infections and tests may return negative during this phase, leading to misdiagnosis.
- Need for follow-up testing after the initial negative result, especially within 2-4 weeks post-exposure.