Varicella zoster virus (VZV) is responsible for chickenpox and a recurrent infection known as shingles or herpes zoster. Most cases of shingles occur after the age of 50, or in people with compromised immune systems. Each year, at least 1,000,000 people in the United States get shingles.
Only people who have had chickenpox or received varicella vaccine can get shingles. During the acute phase of infection (chickenpox), VZV spreads through the body to nerve ganglia in the nervous system. VZV can persist for years in the nerve ganglia and in 10-20% of people will later reactive to cause shingles. The conditions for reactivation are poorly understood; however, aging, immunosuppression, intrauterine VZV exposure and VZV infection before 18 months of life are associated with recurrent infection.
Shingles is common in people with immune systems that have been compromised or weakened by diseases (e.g. cancer, HIV), or drugs (steroids, chemotherapy).
Shingles is characterized by a painful rash with fluid-filled lesions (vesicles) that occurs on one side of the face or body and lasts 2-4 weeks. Approximately 15% of zoster patients experience pain (often severe), numbness, itching or burning lasting several weeks. Symptoms may also include fever, headache, chills and upset stomach. Sometimes pain can be permanent (1/5 people), a condition known as post-herpetic neuralgia, resulting from permanent damage to sensory nerves.
Shingles is not contagious: you cannot get shingles through exposure to someone with shingles. However, you can get chickenpox from someones who has shingles. Although uncommon, people who have not been vaccinated against varicella and have not had natural VZV infection (chickenpox) can contract chickenpox from someone with recurrent infection (shingles). In these cases, transmission occurs during exposure when the rash is in the blister-phase, NOT through sneezing or coughing.
Complications of shingles include:
- pneumonia
- cranial nerve palsies (paralysis resulting from damage to cranial nerves)
- contralateral hemiplegia (paralysis on one side of the body)
- visual impairment or blindness
- encephalitis (inflammation of the brain)
- death due to disseminated infection (mostly in immunocompromised individuals)
A vaccine is available to reduce the risk of shingles. Zostavax, a live virus vaccine, reportedly boosts immunity against varicella-zoster virus, protecting against zoster and its complications. Vaccination involves a single injection under the skin of the upper arm, and is recommended for adults 60 years of age and older. Zostavax has been shown to reduce the risk of shingles by half in older individuals, and to reduce the severity and length of disease in those who do still develop shingles.
The most common side-effects associated with shingles vaccine are redness, discomfort, swelling or itching at the injection site, and headache.
The most common side effects in people who got the vaccine were redness, soreness, swelling or itching at the shot site, and headache.
