HIV/AIDS: Transmission and Pathophysiology

• HIV (human immunodeficiency virus) is a retrovirus causing immunosuppression and opportunistic infections.
• AIDS (acquired immunodeficiency syndrome) is the final stage of HIV, with a severely compromised immune system.
• HIV primarily infects CD4+ T cells (T helper cells), which are critical for immune function.
• HIV replicates within CD4+ T cells, leading to cell destruction and reduced CD4+ T cell count.

Transmission of HIV

• HIV transmits through infected blood, semen, vaginal secretions, or breast milk.
• Unprotected sex with an infected partner is a main transmission mode.
• Sharing needles or syringes can transmit HIV.
• Infected mothers can transmit HIV to babies during pregnancy, childbirth, or breastfeeding.
• HIV does not spread through casual contact like hugging or sharing utensils.

Pathophysiology

• HIV enters the body and attaches to CD4+ T cells.
• Viral RNA converts to DNA via reverse transcriptase, integrating into the host's genome.
• The virus replicates, producing particles that infect more CD4+ T cells.
• CD4+ T cell count decreases over time, weakening the immune system.
• Normal CD4+ T cell count: 800-1200 cells/µL; problems start below 500 cells/µL; severe issues below 200 cells/µL.
• Opportunistic infections and cancers appear as the immune system weakens.

Acute Infection

• Occurs 2-4 weeks post-infection.
• Symptoms include fever, swollen lymph nodes, sore throat, headache, malaise, nausea, muscle/joint pain, diarrhea, and/or rash.
• Characterized by high viral load and high infectiousness.
• CD4+ T cell counts temporarily drop, then return to baseline.

Asymptomatic Infection

• The time from untreated HIV to AIDS diagnosis is about 10 years.
• CD4+ T cell counts stay above 500 cells/µL, and viral load is low.

Symptomatic Infection

• CD4+ T cell counts decline to 200-500 cells/µL.
• Viral load increases.
• Symptoms worsen e.g. persistent fever, night sweats, chronic diarrhea, recurrent headaches, severe fatigue
• Other problems include thrush, shingles, oral hairy leukoplakia, Kaposi sarcoma, and bacterial infections.

AIDS

• Occurs when the immune system is severely compromised.
• CD4+ T cell count drops below 200 cells/µL.
• Development of opportunistic infections, cancers, wasting syndrome, and/or AIDS dementia complex (ADC).

Diagnostic Tests

• HIV antibody tests (e.g., ELISA) detect HIV antibodies.
• Positive ELISA results are confirmed with Western blot or immunofluorescence assay.
• HIV antigen tests (e.g., p24 antigen test) detect HIV antigens.
• Nucleic acid tests (NAT) or viral load tests measure HIV RNA.
• CD4+ T cell count measures the number of CD4+ T cells.

Collaborative Care

• Monitor disease progression and immune function.
• Manage symptoms.
• Prevent opportunistic diseases and complications of therapies.
• Prevent further HIV transmission.

Drug Therapy

• Antiretroviral therapy (ART) suppresses HIV replication, slowing disease progression.
• ART uses drug combinations from different classes.
• Nucleoside reverse transcriptase inhibitors (NRTIs) inhibit reverse transcriptase, preventing HIV RNA from converting into DNA.
• Non-nucleoside reverse transcriptase inhibitors (NNRTIs) also inhibit reverse transcriptase.
• Protease inhibitors (PIs) block protease, preventing HIV from assembling new viral particles.
• Fusion inhibitors prevent HIV from entering CD4+ T cells.
• Entry inhibitors block HIV from attaching to and entering CD4+ T cells.
• Integrase inhibitors block integrase, preventing HIV DNA from integrating into the host cell's genome.

Prophylactic Medications

• Medications prevent opportunistic infections like PCP, MAC, CMV, and fungal infections.

Nursing Management: Assessment

• Assess risk factors and symptoms of HIV infection, such as fatigue, fever, weight loss, and skin lesions.
• Monitor CD4+ T cell count and viral load.
• Assess for opportunistic infections and cancers.
• Assess patient knowledge, psychosocial status, and support system.

Nursing Management: Nursing Diagnoses

• Risk for infection.
• Imbalanced nutrition: less than body requirements.
• Deficient knowledge.
• Social isolation.
• Chronic pain.

Nursing Management: Planning

• Prevent HIV spread, promote a healthy lifestyle.
• Maintain/restore a healthy immune system.
• Prevent opportunistic infections and manage symptoms.
• Improve quality of life.

Nursing Management: Implementation

• Educate about HIV transmission, prevention, ART, and treatment adherence.
• Provide emotional support and counseling.
• Promote healthy lifestyle: nutrition, exercise, and stress management.
• Monitor/manage opportunistic infections.
• Advocate for patient rights and access to care.

Nursing Management: Evaluation

• Evaluate ART effectiveness in suppressing HIV and improving immune function.
• Evaluate treatment adherence and patient understanding.
• Evaluate psychosocial status, support system, and quality of life.

Prevention

• Primary prevention focuses on preventing initial HIV infection.
• Safe sex practices such as using condoms can reduce transmission risk.
• Avoid sharing needles/syringes to prevent transmission among injection drug users.
• Pre-exposure prophylaxis (PrEP) involves daily ART for high-risk individuals.
• Screening blood products has greatly reduced HIV transmission via transfusions.

Psychosocial Issues

• Stigma and discrimination.
• Anxiety and depression.
• Social isolation.
• Grief and loss.
• Financial concerns.

Gerontologic Considerations

• Older adults may be diagnosed later in the disease course.
• Older adults may have other health issues complicating HIV treatment and age-related changes affecting their adherence.
• Older adults may face unique psychosocial challenges related to HIV.