HIV AIDS

Care of the Patient with HIV/AIDS

Overview

  • Emerging Infectious Agent:
      - Possible animal to human transfer occurred in the 1950s.

  • History of AIDS:
      - 1981: Various cases of Pneumocystis jiroveci pneumonia & Kaposi Sarcoma observed in young, healthy gay men.
      - Syndrome termed: AIDS (Acquired Immunodeficiency Syndrome).
      - 1983: Identification of antibody related to the virus.
      - 1984: Isolation of Human Immunodeficiency Virus (HIV).

Pathophysiology/Etiology of HIV & AIDS

  • HIV vs. AIDS:
      - HIV (Human Immunodeficiency Virus):
        - A retrovirus that invades the immune system.
        - Results in HIV infection, which can lead to AIDS.
      - AIDS (Acquired Immune Deficiency Syndrome):
        - The final stage of HIV infection characterized by severe symptoms and profound immunosuppression.
        - Manifested by opportunistic infections and unusual neoplasms.

Pathophysiology of HIV

  • Mechanism of Infection:
      - HIV attaches to target cells (specifically, CD4 receptors on T-Lymphocytes).
      - Uncoating and Entry:
        - Virus uncoats and enters the host cell.
      - Reverse Transcription:
        - HIV converts its single-stranded RNA to double-stranded DNA using the enzyme reverse transcriptase.
      - Integration:
        - Virus enters the nucleus of the CD4+ T-lymphocyte and integrates itself into the host chromosomes.   

The HIV Life Cycle: Stages of Infection

  1. Binding (Attachment):
       - HIV binds to receptors on the CD4 cell surface.
       - Drug Class: CCR5 Antagonists & Post-Attachment Inhibitors.

  2. Fusion:
       - HIV envelope fuses with CD4 cell membrane allowing entry.
       - Drug Class: Fusion Inhibitors.

  3. Reverse Transcription:
       - Inside the CD4 cell, HIV uses reverse transcriptase to convert HIV RNA into HIV DNA.
       - Drug Class: NRTIs & NNRTIs.

  4. Integration:
       - HIV's viral DNA integrates into the CD4 cell's DNA using integrase.
       - Drug Class: Integrase Inhibitors.

  5. Replication:
       - Integrated viral DNA utilizes the CD4 cell's machinery to produce HIV proteins.

  6. Assembly:
       - New HIV proteins and RNA assemble into immature (noninfectious) virus.

  7. Budding:
       - Immature virus pushes out from the host cell, releasing protease that matures the virus.
       - Drug Class: Protease Inhibitors.

Stages of HIV

  • Stage 0: Positive HIV test.

  • Stage 1: HIV+; CD4 count 500 cells/mm³ or more.

  • Stage 2: HIV+; CD4 count 200 - 499 cells/mm³; no AIDS-defining illnesses present.

  • Stage 3: HIV+; CD4 count <200 cells/mm³ or <14% AND an AIDS-defining illness.

AIDS Definition

  • AIDS is a viral disease caused by HIV characterized by:
      - CD4+ count <200 cells/mm³ or <14%.
      - Manifestations include opportunistic infections and unusual neoplasms.

Difference between HIV and AIDS:

  • HIV:
      - Virus causing HIV infection, damaging the immune system by killing CD4 cells.
      - Progression to AIDS occurs in about 10 years without treatment.

  • AIDS:
      - Last stage of HIV infection; marked by increased HIV levels and decreased CD4 count.
      - Medicines can prevent progression to AIDS.

Risk Factors for HIV

  • Behavioral Factors:   - Sexual contact with high-risk individuals (heterosexual or homosexual).   - IV drug use.

  • Occupational Risk:
      - Healthcare workers (due to exposure).

  • Perinatal Transmission:
      - 25% risk of transmission without therapy; 8% with therapy at the time of delivery.

  • Poverty can also increase susceptibility to infection.

Exposure and Prophylaxis

  • Pre-Exposure Prophylaxis (PrEP):
      - HIV-specific antiretroviral drugs taken daily, e.g., Truvada, for high-risk populations.

  • Post-Exposure Prophylaxis (PEP):
      - For occupational or non-occupational exposure (e.g., needlesticks, sexual assault) started within 24-36 hours of exposure.

Clinical Manifestations of HIV

  • Early Symptoms of HIV:   - Flu-like symptoms, fever, headache, rash.

Clinical Manifestations of AIDS

  • Symptoms Include:   - Integumentary: Dry skin, poor wound healing, skin lesions, night sweats.
      - CNS: Confusion, dementia, fever, headache, personality changes.
      - Gastrointestinal (GI): Diarrhea, weight loss, nausea & vomiting.
      - Respiratory: Cough and shortness of breath (SOB).

Opportunistic Infections and Malignancies in AIDS

  • Opportunistic Infections:
      - Protozoal: pneumocystis jiroveci pneumonia.
      - Fungal: candidiasis.
      - Bacterial: mycobacterium avium complex, mycobacterium tuberculosis.
      - Viral: cytomegalovirus, herpes simplex, varicella zoster.

  • Malignancies:
      - Kaposi’s Sarcoma, Non-Hodgkin’s lymphoma, Hodgkin’s lymphoma, invasive cervical cancer.

Diagnostics for HIV & AIDS

  • Lab Assessment:   - Complete blood count (CBC) shows decreased WBC (1,500 – 4,500).
      - CD4+ T-cell count <200.   - Antibody/antigen tests (ELISA).   - 4th generation assays detect HIV-IgM & IgG antibodies.   - Viral load testing—helps determine infectivity or therapy effectiveness, detectable about 10 days post-infection (high viral loads could be >80,000).

  • Diagnostic Assessment:
      - Dependent on patient’s symptoms—may include biopsies (skin, lymph nodes, lungs, liver, GI tract), stool tests for ova/parasites, chest x-ray, pulmonary function tests, arterial blood gas (ABG), bronchoscopy, endoscopy, or colonoscopy.

Pharmacological Therapy for HIV & AIDS

  • Treatment Approaches:
      - Monotherapy: inhibits viral replication, promotes drug resistance, does not improve lifespan.
      - Combination antiretroviral therapy (cART): reduces viral load, slows disease progression, not curative, can preserve health and prolong life.
      - Highly Active Antiretroviral Therapy (HAART): similar to cART; focus on improving life expectancy.

  • Drug Classes:
      - Nucleoside Reverse Transcriptase Inhibitors (NRTIs).

Nursing Process for HIV & AIDS

  • Assessment:
      - Obtain health history (both psychosocial and physical).

  • Nursing Diagnosis Examples:
      - Ineffective Coping
      - Imbalanced Nutrition
      - Anxiety
      - Knowledge Deficit.

Planning for Patients with HIV/AIDS

  • Identified Risks Include:
      - Risk for infection due to reduced immunity
      - Inadequate gas exchange (respiratory concerns)
      - Anemia
      - Inadequate nutrition due to symptoms (nausea/vomiting/diarrhea).   

Patient Education for HIV/AIDS

  • Important Factors:
      - Aim for >90% adherence to therapy.
      - Prevention of secondary infections
      - Effective coping strategies
      - Healthy sexual practices and related lifestyle modifications, especially during pregnancy.