Herpes zoster, commonly known as shingles, is a viral infection that causes a painful rash. This condition arises from the reactivation of the varicella-zoster virus (VZV), the same virus responsible for chickenpox. Understanding its transmission is important for prevention. This article aims to clarify the transmission routes of shingles, specifically addressing whether it is an airborne illness.
How Herpes Zoster Spreads
Herpes zoster is generally not considered an airborne disease like the flu or measles. The primary method of transmission is direct contact with fluid from active rash blisters, which contain many virus particles.
Once the blisters have dried and crusted over, the virus can no longer be spread in this manner. Casual contact, such as being in the same room or sharing items without direct contact with the rash, usually does not lead to transmission. While rare, airborne transmission of VZV from a localized shingles rash has been reported in very close living situations, such as within a household. This is distinct from the widespread airborne transmission associated with chickenpox.
The Link Between Shingles and Chickenpox
Both shingles and chickenpox are caused by the same varicella-zoster virus (VZV). After a person recovers from chickenpox, the VZV remains inactive in their body, typically residing in nerve cells. Shingles develops when this dormant virus reactivates, often years or decades later, commonly due to factors like aging or a weakened immune system.
An individual with shingles cannot directly transmit shingles to another person. However, they can transmit the varicella-zoster virus to someone who has never had chickenpox or has not been vaccinated against VZV. If exposed to the virus from a shingles rash, this non-immune individual will develop chickenpox, not shingles. Thus, while shingles itself is not contagious, the virus can spread, causing chickenpox in susceptible individuals.
Minimizing Transmission Risk
Several practical steps can help reduce the risk of transmitting the varicella-zoster virus from a person with shingles. Covering the rash completely is an effective way to prevent others from coming into direct contact with the blister fluid. Frequent handwashing with soap and water is also important, especially after touching the rash or applying medication.
Individuals with shingles should avoid direct contact with people who are at higher risk for severe illness if they contract chickenpox. This includes pregnant women who have no immunity to chickenpox, premature infants, low birth weight babies, and anyone with a compromised immune system.
The shingles vaccine, such as Shingrix, is recommended for adults aged 50 and older and for adults aged 19 and older with weakened immune systems. This vaccination significantly reduces the likelihood of developing shingles, thereby indirectly limiting the potential for virus transmission.