Shingles is a viral infection that causes a painful rash, originating from the varicella-zoster virus (VZV). This is the same virus responsible for chickenpox. After an individual experiences chickenpox, VZV can remain dormant within nerve cells, potentially reactivating years later as shingles. This article examines how long VZV might survive on inanimate surfaces and the associated potential for indirect transmission.
The Varicella-Zoster Virus
VZV is a human herpesvirus that establishes latency after a primary infection. The initial infection, chickenpox, is highly contagious. It spreads primarily through airborne transmission or direct contact with fluid from characteristic blisters.
Shingles occurs when latent VZV reactivates, leading to a localized rash of fluid-filled blisters. Unlike chickenpox, shingles transmission mainly occurs through direct contact with the fluid from these open shingles blisters.
How VZV Survives on Surfaces
The varicella-zoster virus is fragile and does not survive for extended periods outside the human body, especially on inanimate surfaces (fomites). Research indicates that VZV typically remains viable for only a few hours on surfaces.
Several factors influence the virus’s survival time on surfaces. These include temperature, humidity levels, the type of surface (e.g., porous versus non-porous materials), and the presence of organic matter. A cool, moist environment might allow for slightly longer survival.
Despite its potential to exist on surfaces, transmission of shingles specifically via contaminated surfaces is considered extremely rare and is not a significant route of spread. While VZV DNA has been detected on environmental surfaces in studies involving patients with herpes zoster, the presence of viral DNA does not necessarily mean the virus is infectious.
For chickenpox, fomite transmission is slightly more plausible due to the higher viral load often present in chickenpox lesions and its more easily spread nature. However, even for chickenpox, the virus does not live long on surfaces.
Preventing Indirect VZV Transmission
Given the low, but present, potential for VZV transmission from contaminated surfaces, general hygiene practices are beneficial, particularly in households where someone has active shingles or chickenpox. Frequent handwashing with soap and water is an important step to reduce the spread of many germs, including VZV. This is especially relevant after any potential contact with an infected person or their environment.
Cleaning and disinfecting frequently touched surfaces can further minimize any potential risk. Items such as doorknobs, light switches, countertops, and shared objects should be cleaned with common household disinfectants. These can include solutions containing bleach or alcohol-based cleaners, which are effective at inactivating viruses. Additionally, avoiding the sharing of personal items like towels, clothing, or bedding with someone who has active blisters provides an extra layer of precaution.