Shingles Transmission and Prevention

Mechanism of Transmission

Shingles transmits varicella-zoster virus (VZV) through direct contact with fluid from the vesicular lesions or through inhalation of aerosolized particles from these lesions, according to the Centers for Disease Control and Prevention (CDC) 1
The virus cannot be transmitted through respiratory secretions in the same way chickenpox spreads, making shingles less contagious than primary varicella infection, as reported by the CDC 1
Airborne transmission has been documented in healthcare settings from patients with either localized or disseminated shingles, resulting in chickenpox in susceptible individuals who had no direct contact with the infected person, as noted by the CDC 1

Susceptible individuals—those without prior chickenpox infection or varicella vaccination—can develop chickenpox (not shingles) after exposure to someone with active shingles, according to the CDC and the American Academy of Pediatrics 1, 2, 3
The secondary attack rate for varicella can reach 90% among susceptible contacts, as reported by the CDC 1
High-risk populations requiring particular protection include pregnant women, immunocompromised patients, unvaccinated infants, and individuals without detectable VZV antibodies, as identified by the CDC and the Infectious Diseases Society of America 2, 3, 4

Patients with shingles remain contagious from the time vesicular lesions appear until all lesions have completely crusted over, according to the CDC 1
Localized shingles is considerably less infectious than chickenpox or disseminated shingles, as reported by the CDC 1
Disseminated shingles (involving multiple dermatomes or visceral organs) is considered as infectious as primary varicella and requires airborne precautions, as noted by the CDC 1

Nosocomial transmission of VZV from patients with shingles has been well-documented, with airborne spread occurring even without direct contact with the index patient, as reported by the CDC 1
Healthcare personnel and other patients who are susceptible to VZV are at risk of developing chickenpox after exposure to a patient with shingles, according to the CDC 1

Varicella-zoster immune globulin (VZIG) should be administered to susceptible high-risk individuals within 96 hours of exposure to someone with active shingles, as recommended by the CDC and the American Academy of Pediatrics 2, 3, 4
Household contacts of susceptible HIV-infected or immunocompromised persons should be vaccinated against VZV to prevent transmission, as recommended by the CDC and the Infectious Diseases Society of America 2, 3, 4