Immune & Infectious Disease
✅ Reviewed by NCLEXDeck Clinical Review Board — Updated June 2026
Comprehensive NCLEX-RN Review — Isolation Precautions, HIV/AIDS, Sepsis, Autoimmune Disorders, and Infection Basics
1. Isolation Precautions
Memorize these — very high yield. Standard Precautions apply to ALL clients (hand hygiene, gloves/PPE with anticipated contact with blood/body fluids).
Transmission-Based Precautions
| Type | Examples | PPE / Room |
|---|
| Airborne | TB, measles (rubeola), varicella (chickenpox), disseminated zoster, COVID (aerosolizing) | Negative-pressure room, N95 respirator, door closed |
| Droplet | Influenza, pertussis, meningitis (Neisseria), mumps, rubella, pneumonia, strep pharyngitis | Private room (or 3+ ft spacing), surgical mask |
| Contact | MRSA, VRE, C. difficile, RSV, scabies, wound infections | Gown + gloves, private room, dedicated equipment |
Mnemonic — Airborne: "My Chicken Hez TB" — Measles, Chickenpox/varicella, disseminated Herpes zoster, TB.
Special Notes
- C. difficile & norovirus: Contact precautions + soap and water (alcohol gel does NOT kill spores). Bleach for cleaning.
- Neutropenic (protective) precautions: protect the immunocompromised client — private room, no fresh flowers/raw produce, meticulous hand hygiene, avoid sick visitors.
⭐ NCLEX TIP
PPE donning order: gown → mask/respirator → goggles → gloves. Doffing: gloves → goggles → gown → mask (remove most contaminated first; mask last, outside room).
2. HIV / AIDS
Pathophysiology
HIV attacks CD4+ T-helper cells, progressively weakening cell-mediated immunity.
Key Labs
- CD4 count: normal ~500–1,500. AIDS defined at CD4 < 200 or an AIDS-defining opportunistic infection.
- Viral load: goal is undetectable on therapy. Undetectable = untransmittable (U=U).
Opportunistic Infections
Appear as CD4 drops: Pneumocystis jirovecii pneumonia (PCP), candidiasis, Kaposi's sarcoma, CMV retinitis, TB, toxoplasmosis.
Nursing Management
- ART (antiretroviral therapy) — combination regimen; adherence is critical
- Standard precautions; HIV is not spread by casual contact
- Monitor for opportunistic infections; prophylaxis when CD4 low
- Nutrition, psychosocial support, education on transmission and prevention (PrEP)
3. Sepsis & Septic Shock
Continuum
Infection → sepsis → severe sepsis → septic shock (distributive shock).
Signs
- Early ("warm"): fever, tachycardia, tachypnea, warm flushed skin, bounding pulses, altered mental status, elevated lactate
- Late ("cold"): hypotension, cool clammy skin, decreased urine output, organ dysfunction, worsening lactate
Priority Interventions (Sepsis Bundle)
- Obtain blood cultures BEFORE antibiotics
- Broad-spectrum antibiotics within 1 hour
- Aggressive IV fluid resuscitation (crystalloids)
- Measure/trend serum lactate
- Vasopressors (norepinephrine first-line) if hypotension persists after fluids
- Monitor urine output, MAP (goal ≥ 65), oxygenation
⭐ NCLEX TIP
In sepsis, the two "do first" actions are cultures before antibiotics and rapid fluids + antibiotics. Watch for subtle early signs (new confusion, mild fever + tachycardia) as the intended answer.
4. Autoimmune Disorders
SLE (Lupus)
Butterfly (malar) rash, photosensitivity, joint pain, multi-organ. Protect from sun; monitor kidneys (lupus nephritis).
Rheumatoid Arthritis
Symmetric joint inflammation, morning stiffness > 1 hr. DMARDs, methotrexate.
Anaphylaxis
Type I hypersensitivity — airway swelling, wheezing, hypotension. First drug = epinephrine IM; maintain airway; supine with legs elevated.
Latex Allergy
Cross-reacts with banana, avocado, kiwi, chestnut.
5. Infection Basics & Immunity
- Chain of infection: agent → reservoir → portal of exit → mode of transmission → portal of entry → susceptible host. Breaking any link stops spread.
- Stages of infection: incubation → prodromal → illness → convalescence
- Active immunity: body makes antibodies (infection or vaccine, long-lasting)
- Passive immunity: antibodies given (maternal, immunoglobulin, immediate but temporary)
- Live vaccines (MMR, varicella, intranasal flu) — contraindicated in pregnancy and immunocompromised