HIV and AIDS
Key Points
- HIV (human immunodeficiency virus) progressively destroys CD4+ T-helper lymphocytes, impairing cell-mediated immunity.
- AIDS (acquired immunodeficiency syndrome) is diagnosed when the CD4 count falls below 200 cells/µL or an AIDS-defining illness occurs.
- Antiretroviral therapy (ART) suppresses viral replication, restores immune function, and prevents progression — but does not cure HIV.
- Adherence is the highest-priority nursing concern — missed doses lead to drug resistance and treatment failure.
- Standard precautions must be used with ALL patients regardless of HIV status.
- In pregnancy, universal screening and sustained viral suppression with ART are central to reducing perinatal transmission.
Pathophysiology
HIV binds to CD4+ receptors and CCR5/CXCR4 co-receptors on T-helper lymphocytes. Reverse transcriptase converts viral RNA to DNA, which integrase incorporates into host cell DNA. The infected cell becomes a viral factory, producing new HIV particles that bud off and infect additional CD4 cells.
As CD4 cells are destroyed, cell-mediated immunity progressively deteriorates, leaving the patient vulnerable to opportunistic infections — pathogens that would not cause disease in immunocompetent individuals.
Stages of HIV Infection
| Stage | CD4 Count | Characteristics |
|---|---|---|
| Stage 1: Acute HIV | ≥500 cells/µL | Flu-like syndrome 2–4 weeks after exposure; high viral load; highly infectious |
| Stage 2: Chronic HIV | 200–499 cells/µL | Often asymptomatic; slow viral replication continues; still transmissible |
| Stage 3: AIDS | <200 cells/µL | Opportunistic infections; wasting syndrome; high viral load; life-threatening |
CD4-based staging supports risk stratification, but classification is not back-staged simply because CD4 count rises after treatment response.
Transmission Routes
- Sexual contact (most common): unprotected vaginal, anal, or oral sex
- Blood-to-blood: sharing IV drug needles, contaminated blood products, needlestick injuries
- Perinatal: transplacental, during childbirth, or via breast milk
HIV is not transmitted by casual contact (handshakes, hugging, shared food/water, coughing, sneezing).
Opportunistic Infections (AIDS-defining illnesses)
| Infection | CD4 Threshold | Description |
|---|---|---|
| Pneumocystis jirovecii pneumonia (pneumonia) (PCP) | <200 cells/µL | Most common AIDS-defining infection; prophylaxis with TMP-SMX |
| Toxoplasma encephalitis | <100 cells/µL | Brain lesions; headache, altered consciousness |
| Cytomegalovirus (CMV) retinitis | <50 cells/µL | Progressive blindness if untreated |
| Mycobacterium avium complex (MAC) | <50 cells/µL | Disseminated infection; fever, night sweats, weight loss |
| Kaposi sarcoma | AIDS-defining | Purplish skin lesions; HHV-8 associated |
Nursing Assessment
NCLEX Focus
Monitor CD4 count (immune reserve) and viral load (treatment effectiveness) at every visit. Undetectable viral load (<50 copies/mL) confirms ART effectiveness. CD4 <200 triggers prophylactic antibiotics for PCP.
- Monitor CD4 count and viral load trends.
- Ensure screening access cadence: test at least annually for higher-risk groups, test when evaluating other STIs, and apply prenatal screening with repeat testing in later pregnancy when risk is ongoing.
- In adults 50 years and older, maintain low threshold for testing because HIV symptoms may be misattributed to age-related comorbidity patterns.
- Use test-window logic when evaluating recent exposure:
| HIV Test Type | What it detects | Typical detection window after exposure |
|---|---|---|
| Antibody test | HIV antibodies | Up to about 90 days |
| Antigen/antibody test | HIV antibodies + p24 antigen | About 18-45 days (venous sample), 18-90 days (fingerstick) |
| Nucleic acid test (NAT) | HIV RNA (virus directly) | About 10-33 days |
- Assess for constitutional symptoms: fever, night sweats, weight loss, fatigue, lymphadenopathy.
- Assess for opportunistic infection signs: oral candidiasis (thrush), herpes outbreaks, pneumonia symptoms, neurological changes.
- Assess ART adherence: pill counts, refill history, patient self-report, identify barriers.
- Assess for ART adverse effects: GI symptoms, hepatotoxicity, metabolic syndrome (PI-associated), peripheral neuropathy (older NRTIs).
- Assess mental health: depression, anxiety, and stigma-related distress are common.
- Assess social determinants: housing stability, food security, social support — all affect adherence.
Nursing Interventions
- ART adherence counseling: Non-judgmental approach; explore barriers (cost, side effects, depression, schedule complexity); reinforce that consistent adherence achieves undetectable viral load.
- Infection prevention: Educate on hand hygiene, avoiding undercooked foods, avoiding exposure to individuals with active infections; practice respiratory hygiene.
- Standard precautions: Apply standard precautions with ALL patients regardless of HIV status — gown, gloves, mask, eye protection per exposure risk.
- Transmission prevention education: Consistent condom use; U=U principle (Undetectable = Untransmittable — when viral load is undetectable, sexual transmission risk approaches zero); clean needle programs; PrEP for partners.
- PrEP (pre-exposure prophylaxis): Offer to HIV-negative high-risk individuals using oral daily or long-acting injectable options (commonly every 8 weeks); requires baseline and interval HIV monitoring.
- PEP (post-exposure prophylaxis): Must start within 72 hours of potential exposure; ART regimen continued for 28 days.
- Preconception planning: Counsel patients planning pregnancy to optimize ART adherence, avoid unprotected intercourse until viral suppression is stable, and reduce alcohol/tobacco/illicit-drug exposure.
- Perinatal prevention: In pregnancy with HIV, rapid ART initiation and viral-load-directed delivery planning are key; suppression greatly reduces vertical-transmission risk.
- Infant feeding counseling in HIV pregnancy/postpartum care: Discuss formula or donor milk options; if breastfeeding is chosen, reinforce continuous maternal ART adherence and counseling on the residual but low transmission risk when viral suppression is maintained.
- Psychosocial support: Therapeutic communication; preserve dignity and confidentiality; connect to HIV support groups and mental health services.
- Nutrition: Consult dietician; maintain adequate protein and caloric intake; address wasting syndrome.
- Interdisciplinary care coordination: Align infectious-disease, primary-care, nursing, pharmacy, nutrition, social-work, and behavioral-health plans to support adherence, interaction safety, and long-term stability.
Needlestick Exposure Protocol
Following a needlestick or mucocutaneous exposure to HIV+ blood: (1) Wash site immediately with soap and water; (2) Report to occupational health immediately; (3) Obtain exposure-related baseline/partner testing per protocol if possible; (4) Start post-exposure prophylaxis (PEP) within 72 hours — delay reduces effectiveness; (5) Continue PEP for 28 days.
Pharmacology
See antiretroviral-therapy for complete ART drug class overview (NRTIs, NNRTIs, PIs, INSTIs, fusion inhibitors, CCR5 antagonists).
| First-Line Regimen Example | Drug Classes | Notes |
|---|---|---|
| Bictegravir/TAF/emtricitabine (Biktarvy) | INSTI + 2 NRTIs | Once-daily; high genetic barrier to resistance |
| Dolutegravir + 2 NRTIs | INSTI backbone | Preferred for most patients |
Opportunistic infection prophylaxis:
| CD4 Threshold | Prophylaxis Drug | Target |
|---|---|---|
| <200 cells/µL | TMP-SMX (Bactrim) | PCP (Pneumocystis pneumonia (pneumonia)) |
| <100 cells/µL | TMP-SMX ± pyrimethamine | Toxoplasma encephalitis |
| <50 cells/µL | Azithromycin or clarithromycin | MAC (Mycobacterium avium complex) |
Clinical Judgment Application
Clinical Scenario
A patient with HIV on ART for 2 years has a new CD4 count of 148 cells/µL (previously 380) and a viral load of 12,500 copies/mL (was undetectable). They admit to missing doses “frequently.”
- Recognize Cues: Rising viral load, declining CD4, known adherence failure in patient on established ART.
- Analyze Cues: Nonadherence has allowed viral replication and likely drug resistance development.
- Prioritize Hypotheses: Drug resistance and AIDS-stage immunosuppression are the highest concerns.
- Generate Solutions: Initiate genotypic resistance testing; reassess ART regimen; address adherence barriers; start PCP prophylaxis (CD4 <200); refer to social work for support services.
- Take Action: Non-judgmental adherence counseling; coordinate with infectious disease specialist; begin TMP-SMX prophylaxis per provider order.
- Evaluate Outcomes: Viral load becomes undetectable within 3–6 months with consistent adherence; CD4 recovers toward >200.
Related Concepts
- antiretroviral-therapy — Complete ART drug class overview, mechanisms, and nursing considerations.
- active-and-passive-immunity — HIV destroys cell-mediated immunity; immunosuppression mechanisms.
- immune-system — CD4 T lymphocyte role in adaptive immunity and how HIV depletes immune reserve.
- hepatitis-b — Frequent HIV/HBV co-infection due to shared transmission routes.
- hepatitis-c — HIV/HCV co-infection is common; accelerates HCV fibrosis progression.
- blood-and-body-fluid-exposure-response — Post-exposure prophylaxis (PEP) protocol after potential HIV exposure.
Self-Check
- What CD4 count defines the diagnosis of AIDS, and why does it mark a critical threshold?
- Within what time window must post-exposure prophylaxis (PEP) begin to be effective?
- What does “U=U” mean, and why is it important patient education for HIV transmission prevention?