Airborne Precautions for Shingles
Airborne precautions are required for shingles when the patient has disseminated herpes zoster or localized herpes zoster in an immunocompromised patient, as these presentations carry risk of airborne transmission similar to varicella.
When Airborne Isolation is Indicated
For herpes zoster patients requiring airborne precautions, use airborne infection isolation (AII) rooms that provide:
- Greater than 12 air changes per hour (ACH)
- Negative pressure of at least 2.5 Pa relative to surrounding spaces
- Air exhausted directly outside or HEPA-filtered before recirculation 1
Clinical Decision Algorithm
Disseminated herpes zoster (any patient):
- Lesions extending beyond one dermatome or across midline
- Requires airborne precautions plus contact precautions
- Place in negative pressure AII room
Localized herpes zoster in immunocompromised patients:
- HIV/AIDS, transplant recipients, active chemotherapy, high-dose corticosteroids
- Requires airborne precautions plus contact precautions
- Use AII room due to higher viral loads and potential for aerosolization
Localized herpes zoster in immunocompetent patients:
- Standard and contact precautions only
- Airborne precautions NOT required
- Cover lesions; no special ventilation needed
Important Caveats
While airborne transmission from localized herpes zoster is rare, documented cases exist. A 2021 case report confirmed varicella transmission via airborne route from a father's localized zoster infection to his unvaccinated son, despite no direct contact with lesions 2. This underscores that airborne spread, though uncommon, can occur even with localized disease.
For patients requiring cough-inducing procedures (bronchoscopy, sputum induction) with any form of active herpes zoster, use an AII room or enclosed booth meeting the ventilation specifications above 1.
The key distinction is immunocompetence and disease extent—immunocompromised patients shed higher viral loads and pose greater airborne risk even with apparently localized disease, necessitating airborne precautions as a prudent measure.