From the Guidelines
Herpes zoster (shingles) is contagious, but only to individuals who have never had chickenpox or the chickenpox vaccine, and the risk of transmission is approximately 20% of the risk for transmission from varicella. This is because the varicella-zoster virus can be transmitted from the lesions of patients who have HZ to susceptible contacts, as reported in a household contact study 1. The virus is spread through direct contact with the fluid from shingles blisters, not through coughing, sneezing, or casual contact.
To prevent transmission, individuals with shingles should:
- Keep their rash covered
- Avoid touching or scratching the rash
- Wash their hands frequently
- Avoid contact with pregnant women who have never had chickenpox, newborns, and people with weakened immune systems until their rash has completely crusted over. It is essential to note that once the shingles rash has developed crusts, the person is no longer contagious. Importantly, you cannot catch shingles from someone else with shingles - you can only catch chickenpox if you've never had it before. Shingles itself occurs when the dormant varicella-zoster virus, which remains in the body after a chickenpox infection, reactivates later in life, as explained in the prevention of varicella recommendations 1.
Key points to consider:
- The risk factors for HZ include aging, immunosuppression, and initial infection with varicella in utero or during early childhood 1
- The most common complication of HZ is postherpetic neuralgia (PHN), which can be sometimes debilitating pain weeks to months after resolution of HZ 1
- Life-threatening complications of HZ can occur, including herpes ophthalmicus, dissemination, pneumonia, and visceral involvement, typically in immunocompromised persons 1
From the Research
Contagiousness of Herpes Zoster
- 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, 3, 4, 5, 6.
- The virus can be spread from person to person through direct contact with the rash, but only to people who have not had chickenpox or have not been vaccinated against it 6.
- People with herpes zoster are contagious until the rash has crusted over, usually within 7-10 days 3.
- However, the risk of transmission is relatively low, and herpes zoster is not as contagious as chickenpox 6.
- It's worth noting that people who have had chickenpox or have been vaccinated against it are not at risk of getting herpes zoster from someone else, but they can still get the virus reactivated later in life 2, 3, 4, 5.
Prevention and Management
- The varicella-zoster virus vaccine can help prevent herpes zoster and its complications, such as postherpetic neuralgia 3, 4, 5.
- Antiviral medications, such as acyclovir, valacyclovir, and famciclovir, can help treat herpes zoster and reduce the risk of complications 2, 3, 4.
- Good skin care, pain management, and prevention of secondary bacterial infections are also important aspects of managing herpes zoster 4.