3D image of virus shaped like a spiky ball

Varicella Zoster Virus (VZV)                                    (src)

Imagine waking up one morning with a sharp pain starting in your upper back and wrapping around one side of your torso in a debilitating embrace. When you look in a mirror to investigate the source of this pain, you realize that you have a bright red rash that covers the area of pain. After a trip to the doctor’s office it is confirmed that you have shingles. Unfortunately, this series of events is very common for older adults as one out of every three people aged 60 years and older will get shingles and 50% of all Americans will have shingles by the time they are 80 years old (NIH Senior Health). Given these statistics, and the fact that most Americans have either had shingles or know of someone who has, it seems important to gain a better understanding of this disease.

Typical shingles rash on one side of the chest.

A childhood virus goes into hiding

SHINGLES image

(A) Transmission electron micrograph. (Image by: E. Palmer and B. Partin) and (B) Illustration of VZV. (Reprinted by permission from Macmillan Publishers Ltd: Nature Reviews Microbiology (L. Zerboni et al.), copyright (2014)).

Shingles (also called zoster) is caused by reactivation of the varicella zoster virus, or VZV. In a natural course of infection with VZV, the initial infection typically occurs during childhood when airborne virus particles are inhaled. Following a 2-3 week incubation period these viral particles cause chickenpox. After the person recovers from this initial infection, the virus goes into a period of hiding or “latency” in sensory neurons called the dorsal root ganglia located near the spinal cord. Once there, the virus stays inactive or latent for many years. The exact trigger for reactivation of the virus is not known, but there seems to be a correlation between immune system suppression and virus reactivation. Factors that can contribute to a decreased immune response include age, stress, treatments for cancer or autoimmune diseases, and being HIV positive. Once the virus is reactivated, pain and tingling are usually the first indicators of shingles, followed by the appearance of a rash that occurs on only one side of the torso or face. Shingles typically resolves within 2-4 weeks after symptoms appear.

Natural life cycle of VZV: (1) Person becomes infected with VZV via airborne viral particles, (2) development of chickenpox (varicella), (3) period of hiding or “latency” in neural ganglia, (4) reactivation, and (5) development of shingles (zoster). (Reprinted by permission from Macmillan Publishers Ltd: Nature Reviews Microbiology (L. Zerboni et al.), copyright (2014)).

There is no cure for shingles; however, treatment with antiviral drugs such as acyclovir, famciclovir, and valacyclovir can quicken healing and help prevent complications. In addition, medications may also be prescribed to help individuals cope with the pain and itching associated with shingles.

Currently, the Centers for Disease and Control (CDC) recommends the shingles vaccine for persons 60 years and older.

One out of every three people aged 60 years and older will get shingles and 50% of all Americans will have shingles by the time they are 80 years old (NIH Senior Health).

There is no cure for shingles; however, treatment with antiviral drugs such as acyclovir, famciclovir, and valacyclovir can quicken healing and help prevent complications.

Is shingles contagious?

A person with shingles is not contagious until the rash appears. If the rash blisters are kept covered then the chance of transmission to other individuals remains low. People with shingles cannot give another person shingles. However, they can transmit VZV to someone who has not had chickenpox or been vaccinated against it. The National Institutes of Health (NIH) recommends that people with shingles avoid contact with immunocompromised individuals, pregnant women who have not had chickenpox or the vaccine, and premature infants until the rash no longer contains blisters and has developed crusts (NIH Senior Health).

Possible complications

One of the most common complications of shingles is post-herpetic neuralgia (PHN). People with PHN suffer with chronic neuropathic (nerve) pain for months or even years after the initial onset of the shingles rash. Combinations of pain-relieving therapies are usually necessary to offer relief from PHN pain. Risk factors for PHN include: severity of the shingles rash, being more than 50 years old, and the presence of a chronic disease such as diabetes. Other complications that may arise from shingles include: (1) vision problems if the shingles rash occurred around the eye, (2) secondary bacterial infection of the rash, (3) depression due to pain and loss of sleep and normal activities, and (4) pneumonia (rarely).

Rates (per 1,000 persons) of zoster (shingles) and PHN by age in the United States (CDC report).

Some good news

Treatment with an antiviral medication within 72 hours of the onset of the rash greatly reduces the chances of developing complications due to nerve damage, and can speed the healing process. People typically do not have shingles more than once.

In 2006, the U.S. Food and Drug Administration (FDA) approved the Zostavax® vaccine for the prevention of shingles in adults 50 years and older. This vaccine has been approved as a preventative measure only and should not be administered to persons who have active shingles. Currently, the Centers for Disease and Control (CDC) recommends the shingles vaccine for persons 60 years and older. Getting the shingles vaccine does not guarantee that you will not get shingles. However, it will likely reduce the length and severity of the disease and can reduce the chance of developing PHN. Given the potential vaccination benefits, why doesn’t the CDC currently recommend routine vaccination for persons 50-59 years old? It is currently unclear how long the shingles vaccine would provide protection for people in this age group. Studies in people 60 years old or older show that protection from shingles decreases 5 years post-vaccination (CDC shingles vaccine). So, if people are vaccinated too early then they may no longer have adequate protection against shingles when they may be most susceptible to it.

Will shingles become a disease of the past some day?

Serologic tests, which measure the levels of antibodies in the blood, show that almost everyone born in the United States before 1980 has had chickenpox. The introduction of routine childhood vaccination with the chickenpox (varicella) vaccine in the United States in 1995 has dramatically changed the incidence of chickenpox. According to the CDC, two doses of the varicella vaccine are 90% effective at preventing chickenpox (CDC chickenpox vaccine). Now that incidence of naturally occurring chickenpox is low, it will be interesting to see if this also helps reduce the levels and severity of shingles in the future. What a great future that would be!

Disclaimer: As with all medical decisions, your personal healthcare provider should be consulted regarding proper diagnosis, treatment, and vaccination decisions.