Overview
This lecture covers the fundamentals of HIV and AIDS, including their pathophysiology, stages, transmission, diagnosis, complications, treatment, and nursing care priorities.
HIV & AIDS Basics
- HIV (Human Immunodeficiency Virus) attacks the immune system, especially CD4+ (helper T) cells.
- AIDS (Acquired Immunodeficiency Syndrome) is the late stage of HIV infection when the immune system is severely weakened.
- HIV progresses through stages: acute, chronic, and AIDS.
Pathophysiology & Life Cycle
- HIV targets cells with CD4 receptors (helper T cells, macrophages, monocytes, dendritic cells).
- Helper T cells release cytokines activating other immune cells.
- HIV is a retrovirus requiring a host cell to replicate.
- Key HIV enzymes: reverse transcriptase, integrase, protease.
- HIV life cycle: attachment → fusion → reverse transcription → integration → replication → assembly/budding → maturation.
Transmission & Risk
- Transmitted via blood, semen, vaginal fluid, or breast milk.
- High viral load increases transmission risk.
- Main activities: unprotected sex, sharing needles, contaminated blood products, pregnancy/breastfeeding.
- Cannot be spread by hugging, closed-mouth kissing, sweat, saliva (without blood), insect bites, or casual contact.
Stages & Diagnosis
- Acute stage: flu-like symptoms, high viral load, most infectious.
- Chronic (asymptomatic) stage: low symptoms, virus still active, can still transmit.
- AIDS stage: CD4 count <200, presence of opportunistic infections.
- Diagnosis: combination antigen/antibody test (p24 antigen), antibody tests, nucleic acid tests (RNA/viral load).
- CD4 count monitors disease progression and treatment effectiveness.
Opportunistic Infections & Complications
- Cancer: Kaposi sarcoma (purple lesions).
- Viral: Cytomegalovirus (CMV), Epstein-Barr virus (oral hairy leukoplakia), Herpes simplex virus.
- Bacterial: Tuberculosis (TB), Salmonella septicemia, Mycobacterium avium complex, Streptococcus pneumoniae.
- Fungal: Candidiasis, Pneumocystis pneumonia (PCP), cryptococcosis, histoplasmosis.
- Protozoal: Toxoplasmosis, cryptosporidiosis, cystoisosporiasis.
Prevention & Patient Education
- W: Water from treated sources only.
- E: Eat fully cooked and pasteurized foods.
- A: Avoid risky activities (unsafe sex, drug use).
- K: Keep vaccinations current (e.g., pneumovax).
- E: Exposure to animal feces minimized.
- N: Necessary to take ART (antiretroviral therapy) as prescribed.
Antiretroviral Therapy (ART)
- ART targets specific steps in HIV life cycle to reduce viral load and increase CD4 count.
- Drug classes: Attachment inhibitors, entry inhibitors, reverse transcriptase inhibitors (non-nucleoside and nucleoside/nucleotide), integrase inhibitors, protease inhibitors.
- Patients must take combination therapy as prescribed to prevent resistance.
Nursing Care & Screening
- Assess risk factors: sexual behavior, drug use, blood transfusion history.
- Annual testing for high-risk individuals; at least once for ages 13-64.
- Education on PrEP (pre-exposure prophylaxis) for high-risk, HIV-negative patients; PEP (post-exposure prophylaxis) after exposure.
- Counsel patients with HIV on transmission prevention, medication adherence, and partner notification/testing.
Pregnancy & HIV
- ART during pregnancy/birth and to newborn can reduce transmission risk to less than 1%.
- HIV-positive mothers should not breastfeed.
Key Terms & Definitions
- CD4+ Cells — White blood cells targeted by HIV, essential for immune response.
- Opportunistic Infection — Infections occurring due to weakened immune system.
- ART (Antiretroviral Therapy) — Medications that suppress HIV replication.
- Viral Load — Amount of HIV RNA in the blood.
- PrEP / PEP — Medications for HIV prevention before/after possible exposure.
Action Items / Next Steps
- Take the provided quiz on HIV/AIDS content.
- Review key opportunistic infections and ART drug classes.
- Practice case scenarios for screening and patient education.
- Stay updated on CDC testing recommendations and guidelines.