Is shingles an airborne virus?

Shingles Is Not an Airborne Virus, But Can Transmit Through Aerosols from Vesicle Fluid

Shingles (herpes zoster) itself is not an airborne virus, but the varicella-zoster virus (VZV) that causes shingles can be transmitted through direct contact with vesicle fluid or through inhalation of aerosols from these lesions. 1, 2

Understanding Shingles and Its Transmission

• Shingles is caused by reactivation of the varicella-zoster virus (VZV) that remains dormant in sensory nerve ganglia after a primary varicella infection (chickenpox) 2
• VZV can be transmitted through:
  • Direct contact with fluid from shingles vesicles 2
  • Inhalation of aerosols from vesicular fluid of skin lesions 1
  • Infected respiratory tract secretions that may be aerosolized 1
• The virus enters a susceptible host through the upper respiratory tract or the conjunctiva 1

Important Distinctions About Shingles Transmission

• A person with shingles cannot give another person shingles directly - they can only transmit VZV, which causes chickenpox in susceptible individuals 2
• Shingles itself occurs only as a reactivation of the virus in someone who previously had chickenpox or the vaccine 2
• Individuals with shingles may be contagious to susceptible children due to the high amount of virus particles in vesicle fluid 3

Period of Contagiousness

• The period of contagiousness begins 1-2 days before the onset of rash and continues until all lesions have dried and crusted, typically 4-7 days after rash onset 1, 2
• For lesions that do not crust (macules and papules), contagiousness ends when no new lesions appear within a 24-hour period 2
• Persons with progressive varicella (development of new lesions for >7 days) might be contagious longer, presumably because their immune response is depressed, allowing viral replication to persist 1

Special Considerations for Healthcare Settings

• Healthcare workers with localized herpes zoster should cover all lesions completely and be restricted from caring for high-risk patients until all lesions have dried and crusted 2
• Healthcare workers with disseminated zoster must be excluded from duty until all lesions have dried and crusted 2
• Transmission-based precautions should be implemented in healthcare settings to prevent the spread of VZV 1

Common Pitfalls to Avoid

• Assuming that starting antiviral therapy immediately makes the patient non-contagious - viral shedding continues until lesions are fully crusted 2
• Inadequate covering of lesions, which can lead to transmission even with localized disease 2
• Failing to recognize that immunocompromised patients may have prolonged periods of viral shedding and contagiousness 2
• Overlooking the possibility of airborne transmission from localized herpes zoster infections, which has been documented in case reports 4

In summary, while shingles itself is not an airborne virus, the varicella-zoster virus that causes it can be transmitted through aerosols from vesicle fluid, making proper precautions necessary to prevent transmission to susceptible individuals.