Infection Control & Resistant Organisms – Comprehensive Class Notes

COVID-19 Review

• PPE for suspected/confirmed cases (highest level): N-95 mask, eye/face shield, gown, gloves, shoe covers.
• Isolation status may vary with circulating strain but default = transmission-based precautions (contact + droplet + airborne until ruled out).
• Key symptoms seen across waves:
– Classic early triad: fever, cough, loss of taste/smell.
– Current strains: wider spectrum – chills, myalgias, or completely asymptomatic.
• Diagnostic testing: nasopharyngeal PCR swab (gold standard).
• No definitive cure; supportive care + antivirals within 48 h of onset/exposure:
– Out-patient: Paxlovid.
– In-patient/long-term care: IV Remdesivir.

Personal Protective Equipment & Precaution Tiers

• Standard/Universal precautions are ALWAYS used (assume every patient potentially infectious).
• Tier 2: Transmission-based precautions triggered once mode of transmission known.
– Contact (gown + gloves): MRSA, C. diff, VRE, ESBL, draining wounds.
– Droplet (mask + eye): Influenza, RSV, meningitis, rubella, pertussis.
– Airborne (N-95 + negative-pressure room): TB, rubeola (measles), varicella, SARS-CoV-2.

Viral & Vector-borne Illnesses Discussed

Epstein–Barr Virus / Infectious Mononucleosis

• “Kissing disease” spread by saliva.
• Differential Dx overlaps with strep throat (fatigue, fever, posterior cervical lymphadenopathy, white tonsillar exudate).
• Diagnosis: throat culture, CBC (atypical lymphocytes), Monospot.
• Supportive care: rest, antipyretics, hydration.

Zika Virus

• Aedes mosquito vector; mainly tropical climates.
• S/Sx: fever, maculopapular rash, conjunctivitis, arthralgia.
• Pregnancy risk: fetal microcephaly, intra-uterine growth restriction, developmental delay.
• Prevention: mosquito control, hand hygiene; no specific antiviral.

Community vs. Health-Care–Associated Infection (HCAI/HAI)

• Community-acquired: contracted outside facility and “brought in” (e.g., CAP pneumonia).
• HAI (formerly “nosocomial”): acquired ≥48 h after admission OR within 90 d of health-care contact.

Susceptible Hosts & Risk Factors

• Post-op, immunocompromised (HIV, chemo, steroids), extremes of age, chronic illness (COPD, ESRD, diabetes), burn or wound patients, ventilated, transplant.
• Devices: central lines, foleys, ET tubes, dialysis catheters.
• Environmental: inadequate cleaning, shared rooms, length of exposure time, staff hand hygiene (“dirty vs. clean nurse” concept).

High-Risk Units

• ICU, burn unit, oncology, transplant, NICU, surgical step-down, long-term vent units.

Common Pathogens

• E. coli – UTIs.
• Staphylococcus aureus (incl. MRSA) – skin, wound, lung, blood.
• Pseudomonas aeruginosa – wounds, urine; green-blue exudate, sweet/grape odor.

Hand Hygiene

• Soap & water 20 s (Happy-Birthday x2) – mandatory after C. diff, visible soil.
• Alcohol-based rub 60!\text{–}!95\% (prefer ≥70 %). Do NOT rinse off.

Asepsis

• Medical/clean technique – reduce organisms; regular bedside care (NG insertion/feeds, routine enemas, ostomy care, med draws, JP/Hemovac drains).
• Surgical/sterile technique – eliminate all organisms. Needed for: urinary catheter insertion (straight & indwelling), central/PICC/midline insertion & dressing changes, tracheostomy creation, lumbar puncture, sterile suctioning, major post-op complex dressing changes, OR procedures.

UV-Light Disinfection

• Mobile UV-C robots used after C. diff or multi-drug resistant organism (MDRO) discharge. Cycle 20 – 120 min based on “bug count.”

Ventilator-Associated Pneumonia (VAP) Bundle

• HOB \ge 30^{\circ} (ideally 30-45).
• Daily sedation vacation & readiness to extubate.
• Peptic ulcer & DVT prophylaxis.
• Oral care q2-4 h with chlorhexidine; closed suction; hyper-oxygenate pre-suction.

Catheter-Associated Urinary Tract Infection (CAUTI)

Appropriate Indications for Indwelling Foley

• Urologic/gynecologic surgery needing strict drainage (prostatectomy, TURP, cystectomy, nephrectomy).
• Epidural anesthesia interfering with sensation.
• Critical care/ hemodynamic instability (shock, multi-drip titration).
• Stage III/IV sacral pressure injury with incontinence.
• End-of-life/hospice comfort.
• Urinary retention with failure of intermittent catheterization.

Nursing Care

• Insert with strict sterile technique; secure tubing to thigh; bag below bladder level; maintain closed system.
• Empty with clean gloves; alcohol swab spout; never let spout touch container/floor.
• Encourage PO fluids; peri-care front-to-back.

Surgical Wound Care

• Monitor edges approximation, exudate amount/color/odor, surrounding erythema, edema, pain.
• Blood ≠ infection; purulent/green/yellow + odor = infection.
• Complex or central-line dressing = sterile gloves; “simple” dry gauze changes may use clean gloves.

Antibiotic-Resistant Organisms

MRSA

• Methicillin-Resistant Staphylococcus aureus.
• Isolation: CONTACT.
• Treatment: Vancomycin IV 1000\,\text{mg} q12h usual adult dose (range 500-1250 mg based on renal function) ± Linezolid/Daptomycin if VISA/VRSA.
• Monitoring:
– Trough (draw </=30 min before 4th dose) goal 10!\text{–}!20\,\mu\text{g/mL}.
– Peak levels no longer routinely required.
– Labs: Creatinine 0.5!\text{–}!1.5\,\text{mg/dL}, BUN 8!\text{–}!20, LFTs.
– Major toxicities: nephro- & oto-toxicity, “Red-man syndrome.” Hydrate well.
• Nasal decolonization: Mupirocin (Bactroban) ointment BID × 5 d.

VRE (Vancomycin-Resistant Enterococcus)

• GI flora gram-positive cocci; survive on surfaces; transmitted contact/fecal-oral.
• Risk: prolonged antibiotics, GI surgery/procedure, immunosuppression, ESRD, cancer.
• Isolation: CONTACT; bleach disinfection.
• Treatment options: Linezolid, Daptomycin, Tigecycline, Ampicillin/Amoxicillin (if sensitive), combination therapy.
• Home care: hand washing, single-use towels, routine linen wash, disposable gloves with body fluids.

CRE & Other MDROs

• Carbapenem-Resistant Enterobacteriaceae – limited to discussion as another contact MDRO requiring strict hand hygiene & cohorting.

Clostridioides (Clostridium) difficile

• Gram-positive spore-former; produces enterotoxins.
• Trigger: broad-spectrum antibiotics (cephalosporins, penicillins, clindamycin, fluoroquinolones).
• S/Sx 5-10 d after antibiotics: watery diarrhea (≥3/24 h), cramping, leukocytosis, fever; severe → 10-15 watery stools, toxic megacolon, perforation, ileus.
• Diagnosis: stool toxin PCR/ELISA.
• Treatment:
– 1st line: Oral Vancomycin 125\,\text{mg} q6h × 10 d or Fidaxomicin.
– Severe/fulminant: Oral Vancomycin + IV Metronidazole 500\,\text{mg} q8h.
– Recurrent: tapered vancomycin, fidaxomicin, bezlotoxumab, or Fecal Microbiota Transplant (FMT).
• Precautions: CONTACT + hand-wash soap & water (alcohol gel ineffective), bleach room cleaning.

Antibiotic Stewardship & Patient Education

• Complete full prescribed course—even if symptoms improve.
• Take with adequate fluids; monitor for side-effects (especially diarrhea >3 days, rash, anaphylaxis).
• Do NOT demand/stockpile antibiotics for viral illness.

Nursing Diagnoses & Interventions (Infection Exemplars)

Respiratory Infection (e.g., Pneumonia)

• Assessment: ↑RR, dyspnea, SpO₂ <92\%, adventitious sounds, productive cough, fever. • Interventions: monitor VS, auscultate lungs, incentive spirometry, C&DB, hydration, antibiotics, oxygen, HOB >30°, splint with pillow.
• Goals: SpO₂ >92\%, clear breath sounds, afebrile, WBC normalize.

Gastro-Intestinal Infection (e.g., C. diff)

• Assessment: watery diarrhea, abdominal pain/distention, dehydration indicators, ↑WBC.
• Interventions: stool culture, contact precautions, replace fluids/e-lytes, skin care, flagyl/vancomycin, probiotic/FMT per order.
• Goals: formed stools, balanced labs, intact skin, no abdominal tenderness.

Urinary Tract Infection

• Assessment: dysuria, frequency, urgency, suprapubic/flank pain, cloudy/foul urine, fever >100.4^{\circ}\text{F}; elderly – acute confusion.
• Interventions: UA & C/S, antibiotics, PO fluids \ge 2\text{ L/day} if allowed, avoid bubble baths/hot tubs, cotton underwear, wipe front→back, remove foley ASAP.
• Goals: clear urine, pain 0-1/10, afebrile.

Practice Scenario Highlight

• Observed CNA lets Foley spout touch floor → RN intervenes, explains contamination risk, demonstrates correct emptying (gloves, keep spout sterile, alcohol wipe).

Quick Reference Values & Angles

• SpO₂ goal generally >92\% (may accept \ge 90\% in COPD/fibrosis).
• HOB: \ge 30^{\circ} routine; 30!\text{–}!45^{\circ} during enteral feeds.
• Fever threshold: \ge 100.4^{\circ}\text{F} (38^{\circ}\text{C}).
• Creatinine: 0.5!\text{–}!1.5\,\text{mg/dL}; BUN 8!\text{–}!20\,\text{mg/dL}.
• Vancomycin trough: 10!\text{–}!20\,\mu\text{g/mL}; infusion ≈ 1 g q12h (adjust).