Infection Prevention & Isolation Precautions
Right hands, right mask, right room, and the bundles that stop device infections
Hand hygiene and standard precautions
Hand hygiene. Clean hands are the single most effective defense against healthcare-associated infection. An alcohol-based hand rub is preferred for routine care because it acts faster, kills more organisms, and irritates skin less than washing. Use it at each of the WHO "5 moments": before touching a patient, before a clean or aseptic procedure, after a body-fluid exposure risk, after touching a patient, and after touching the patient's surroundings. Clean hands again after removing gloves; gloves never replace hand hygiene.
Use soap and water, not alcohol, after caring for a patient with C. difficile (alcohol does not kill spores) or norovirus (a non-enveloped virus relatively resistant to alcohol), and whenever hands are visibly soiled. Friction and rinsing physically remove what alcohol cannot kill.
Standard precautions. These apply to every patient, because all blood and body fluids except sweat are treated as potentially infectious:
- Hand hygiene before and after every contact.
- Gloves for blood, body fluids, mucous membranes, or nonintact skin; gown, mask, and eye protection when splashes are likely.
- Respiratory hygiene: masks and tissues for coughing patients.
- Safe injection practice (one needle, one syringe, one time) and no recapping of used needles.
- A surgical mask for procedures entering the spinal or epidural space, such as lumbar puncture.
PPE order. Don gown, mask or respirator, eye protection, then gloves. Doff gloves first, then eye protection, gown, and mask; a respirator comes off only after leaving the room. Clean hands once all PPE is off.
Transmission-based precautions
These are added on top of standard precautions and begin as soon as an infection is suspected, not after it is confirmed.
| Feature | Contact | Droplet | Airborne |
|---|---|---|---|
| PPE | Gown + gloves on room entry | Surgical mask on room entry | Fit-tested N95 respirator or PAPR |
| Room | Single room or cohort; dedicated equipment | Single room; patient masked for transport | Negative-pressure isolation room (6–12+ air changes/h, air vented outdoors or HEPA-filtered), door closed |
| Spread | Direct touch or contaminated surfaces | Large droplets (>5 μm) that fall within about 3–6 ft | Droplet nuclei (≤5 μm) that stay suspended |
| Classic organisms | MRSA, VRE, ESBL and carbapenem-resistant gram-negatives, C. difficile, norovirus, scabies, lice, RSV | N. meningitidis, H. influenzae type b, influenza, pertussis, mumps, rubella, adenovirus, Mycoplasma, pharyngeal diphtheria | TB, measles, varicella, disseminated zoster |
C. difficile. Add soap-and-water hand hygiene, cleaning of the room and shared equipment with a sporicidal agent such as sodium hypochlorite (bleach), since quaternary ammonium compounds and alcohol leave spores intact, and precautions for at least 48 hours after diarrhea resolves. Stewardship that limits fluoroquinolones, clindamycin, and cephalosporins prevents new cases.
Suspected tuberculosis. Cough for more than 2–3 weeks, night sweats, weight loss, or an upper-lobe cavity, particularly with HIV, incarceration, homelessness, or birth in an endemic country, triggers airborne isolation immediately. It can stop when another diagnosis explains the illness or after three negative AFB sputum smears collected 8–24 hours apart, at least one early-morning specimen. The patient wears a surgical mask whenever leaving the room.
Varicella and zoster. Varicella requires airborne plus contact precautions until every lesion has crusted. Disseminated zoster, or any zoster in an immunocompromised patient until dissemination is excluded, is handled the same way. Localized dermatomal zoster in an immunocompetent patient needs only standard precautions with the lesions covered. Only immune staff should enter these rooms.
| Organism | Precaution | Continue until |
|---|---|---|
| N. meningitidis, H. influenzae type b | Droplet | 24 h of effective therapy |
| Pertussis | Droplet | 5 days of effective therapy |
| Mumps | Droplet | 5 days after parotid swelling begins |
| Rubella | Droplet | 7 days after rash onset |
| Influenza | Droplet | 7 days after onset or 24 h after fever and symptoms resolve, whichever is longer |
| Measles | Airborne | 4 days after rash onset |
| Varicella, disseminated zoster | Airborne + contact | All lesions crusted |
| C. difficile | Contact | At least 48 h after diarrhea resolves |
Empiric precautions by syndrome.
- Fever with petechial rash or suspected bacterial meningitis → droplet.
- Vesicular rash → airborne + contact.
- Cough, fever, and an upper-lobe infiltrate with TB risk → airborne.
- Rash with cough, coryza, and conjunctivitis → airborne (measles).
- Acute diarrhea in an incontinent patient → contact.
Device-associated infection bundles
A bundle is a short set of evidence-based steps performed together every time; reliably completing all of them matters more than any single element.
- Hand hygieneBefore insertion and before every access of the line.
- Maximal sterile barrierCap, mask, sterile gown, sterile gloves, full-body sterile drape.
- Chlorhexidine skin prepMore than 0.5% chlorhexidine in alcohol, allowed to dry.
- Site selectionAvoid the femoral vein in adults; subclavian has the lowest infection risk (but more pneumothorax); ultrasound for jugular lines.
- Daily necessity reviewRemove the line as soon as it is no longer needed.
More on central lines. Replace lines placed emergently without full asepsis within 48 hours. Routine scheduled replacement, guidewire exchange, and prophylactic antibiotics do not prevent infection.
Catheter-associated urinary tract infection (CAUTI). The best prevention is not placing the catheter. Valid indications include acute retention or obstruction, output monitoring in critical illness, selected perioperative use, healing of sacral wounds in an incontinent patient, and end-of-life comfort; incontinence alone is not one, and external catheters or intermittent catheterization are alternatives. Insert aseptically, keep the system closed with the bag below the bladder, and remove early through daily review or nurse-driven protocols. Do not screen for or treat asymptomatic bacteriuria in catheterized patients.
Ventilator-associated pneumonia (VAP). Elevate the head of the bed to limit aspiration; interrupt sedation daily and pair it with a spontaneous breathing trial so patients are extubated early; use subglottic secretion drainage when ventilation is expected beyond 48–72 hours; mobilize early; and change circuits only when soiled or malfunctioning.
Health care workers and outbreaks
Vaccination. Staff need annual influenza vaccine; the hepatitis B series with a post-vaccination anti-HBs check (≥10 mIU/mL indicates immunity); two doses each of MMR and varicella vaccine unless immune; Tdap; and baseline TB screening (IGRA or tuberculin skin test) at hire. Routine annual TB testing is no longer recommended without an exposure.
Staying home. Workers with fever, acute respiratory or gastrointestinal illness, or draining skin lesions should not care for patients. After influenza, return once afebrile for 24 hours without antipyretics; after norovirus, wait 48 hours after symptoms resolve. A nonimmune worker exposed to varicella is off duty from day 8 through day 21 after exposure (day 28 if VariZIG was given).
Clusters. More cases than expected on a unit, linked in time and place, should be reported promptly to the infection prevention team, which confirms the outbreak, tightens precautions, and notifies the health department for reportable diseases.
Meningococcal prophylaxis (rifampin, ciprofloxacin, or ceftriaxone) is for close contacts; health care workers need it only after unprotected exposure to respiratory secretions, such as intubation without a mask.