Healthcare-associated Exposure to the Varicella-Zoster Virus (VZV)

The VZV is transmitted from person-to-person primarily by direct contact with vesicular fluid; inhalation of droplet nuclei from infected respiratory secretions; and less frequently, by contact with freshly contaminated articles and environmental surfaces. If VZV exposure occurs in a healthcare setting, all case-patient contacts should be evaluated immediately for presumptive evidence of immunity.¹⁰ Persons are considered immune only if they have documentation of:

1. physician-diagnosed varicella (chickenpox)

   or

2. physician-diagnosed herpes zoster

   or

3. laboratory evidence of VZV immunity

   or

4. age-appropriate vaccination against the VZV.

   or

5. non immunocompromised or pregnant born in the United States before 1980

All susceptible HCP exposed to the VZV should receive PEP with two doses (4-8 weeks apart) of the varicella-zoster vaccine (Varivax) as soon as possible. Vaccination within 3-5 days of exposure to rash might modify the disease if infection occurred. Vaccination >5 days postexposure is still indicated because it induces protection against subsequent exposures (if the current exposure did not cause infection).¹⁰ HCP who have received the vaccine more than 5 days after the exposure should be excluded from duty for 8-21 days after exposure.¹²

Susceptible HCP exposed to the VZV for whom the vaccine is contraindicated (e.g., pregnant, immunocompromised HCP) should be administered varicella-zoster immunoglobulin (VZIG) no later than 96 hours of an exposure.¹⁰ This recommendation also applies to women exposed to the VZV at any stage of pregnancy. The VZIG product currently used in the United States is VariZIG™.