From the Guidelines
Herpes zoster is contagious, but only through direct contact with the fluid from shingles blisters, and not through casual contact or airborne transmission. The contagious period is estimated to begin 1--2 days before the onset of rash and to end when all lesions are crusted, typically 4--7 days after onset of rash 1. A person with active shingles can transmit the varicella-zoster virus to someone who has never had chickenpox or received the chickenpox vaccine, potentially causing chickenpox in that person. Some key points to consider:
- The virus is spread through direct contact with the fluid from shingles blisters, not through coughing, sneezing, or casual contact.
- Once the shingles rash has developed crusts, the person is no longer contagious.
- To prevent transmission, individuals with shingles should keep their rash covered, avoid touching or scratching the rash, and wash their hands frequently.
- They should also avoid contact with pregnant women who have never had chickenpox, newborns, and people with weakened immune systems. The reason shingles occurs is that after a person recovers from chickenpox, the virus remains dormant in nerve tissues and can reactivate years later as shingles, typically when the immune system is weakened due to stress, aging, or certain medical conditions, as noted in the study on prevention of varicella 1.
From the Research
Herpes Zoster Contagiousness
- Herpes zoster, also known as shingles, is caused by the reactivation of the varicella-zoster virus, which is the same virus that causes chickenpox 2.
- The virus can be spread from person to person through direct contact with the rash, but it is not contagious before the rash appears or after the rash has crusted over 2.
- People with herpes zoster can spread the virus to others who have not had chickenpox or have not been vaccinated against varicella, causing them to develop chickenpox, not shingles 2.
Transmission and Prevention
- The risk of transmission can be reduced by avoiding contact with the rash and keeping the rash covered 2.
- Antiviral medications, such as valacyclovir and famciclovir, can help reduce the severity and duration of herpes zoster, but they do not prevent transmission 3, 4, 5, 6.
- A live, attenuated vaccine is available to reduce the risk of herpes zoster and postherpetic neuralgia, and it is recommended for adults over 60 years old 2.