HIV (Human Immunodeficiency Virus) is a virus that attacks the immune system, specifically targeting CD4 cells (also known as T-helper cells), which are a type of white blood cell essential for immune defense. If untreated, HIV can lead to AIDS (Acquired Immunodeficiency Syndrome), a condition where the immune system is severely weakened, leaving the body vulnerable to opportunistic infections and certain cancers.

### Key Details About HIV:

1. **Transmission:**

   - **Sexual Contact:** Through unprotected sex with an infected partner.

   - **Blood Transmission:** Sharing needles or exposure to infected blood.

   - **Mother-to-Child:** During childbirth, pregnancy, or breastfeeding.

   - **Other Routes:** Rarely through medical procedures if proper sterilization isn't followed.

2. **Stages of HIV Infection:**

   - **Acute HIV Infection:** Occurs 2-4 weeks after infection. Flu-like symptoms may appear.

   - **Chronic HIV Infection:** May last for years without symptoms while the virus slowly damages the immune system.

   - **AIDS:** The final stage, where the immune system is severely compromised.

3. **Symptoms:**

   - Early Stage: Fever, fatigue, rash, sore throat, swollen lymph nodes.

   - Chronic Stage: Often asymptomatic, but HIV continues to weaken the immune system.

   - AIDS: Opportunistic infections, weight loss, night sweats, chronic diarrhea, and more.

4. **Diagnosis:**

   - **Antibody/Antigen Tests:** Detect HIV antibodies and antigens.

   - **PCR Test:** Detects HIV RNA.

   - **CD4 Count:** Measures the health of the immune system.

   - **Viral Load Test:** Measures the amount of virus in the blood.

5. **Treatment:**

   - **Antiretroviral Therapy (ART):** A combination of drugs that suppress the virus and prevent its replication. It cannot cure HIV but allows individuals to lead healthy lives and reduces the risk of transmission.

   - Adherence to ART is crucial for its effectiveness.

6. **Prevention:**

   - **Safe Sex Practices:** Use of condoms and pre-exposure prophylaxis (PrEP).

   - **Needle Exchange Programs:** For those who use injectable drugs.

   - **Regular Testing:** Especially for high-risk individuals.

   - **Mother-to-Child Prevention:** ART during pregnancy and delivery.

7. **Living with HIV:**

   - HIV-positive individuals can live long, healthy lives with proper treatment and care.

   - Reducing stigma and providing support is critical for mental and emotional well-being.

8. **HIV vs. AIDS:**

   - HIV is the virus that causes the disease.

   - AIDS is the most severe stage of HIV infection.

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