Ask the Doctor: The virus that can change your life for ever

Amira (not her real name), at 70 thought that life was good (before she became a patient of mine): The kids had grown up and were successful in their careers, grandchildren were healthy and happy, finances were stable and comfortable and she loved traveling with her husband as they were both “aging well”. And then, one afternoon, she felt a twitch just above her left kidney. In the beginning she thought she had sprained her back after a long mass in the church. That night she did not sleep well and next day she felt even more painful and uncomfortable. It was not until the third day that she noticed several blisters crammed up together exactly where she was feeling pain. By the time she went to see her family doctor, it was already 4 days since the start of the pain. He shook his head and made immediately the diagnosis of Shingles. He then gave her a prescription for antiviral therapy but told her more likely than not it will not work because she had passed the crucial period of 72 hours, during which the treatment has been shown to be effective.

This was the beginning of a new life (or better said, lack of it) for Amira. Excruciating pain (burning and stabbing) became her permanent companion. Even when the blisters dried out the pain never went away. She lost weight, she could not sleep, she had no appetite to eat and isolated herself from friends and relatives. Many drugs gave her side effects sometimes worse than the pain. Her life had changed for ever. Amira’s story, unfortunately, is not unique. As a complication of Shingles she had developed Post Herpetic Neuralgia, a serious neuropathic pain syndrome that has a major preference for older persons.

Shingles, also known as herpes zoster, is caused by the same virus that causes chickenpox, the varicella zoster virus or VZV for short. Once we get infected, the virus remains in our body within the nervous tissues in a dormant (sleeping) state and may wake up much later attacking peripheral nerves, when our immune system weakens. However, there is no way to tell when the virus will become active again. Age represents the most important risk factor for development of shingles.

The chickenpox vaccine was introduced in the USA and Canada about 15 years ago. As it stands today approximately 95% of Canadians 15 years of age or older have been exposed to VZV and therefore, most Canadian adults are at risk for reactivation of this virus. 1 in 3 Canadians are expected to develop shingles over a lifetime and half of adults who live to 85 years of age.

In Canada there are approximately 130,000 new cases of shingles each year (the acute form of VZV infection in adults). Additionally, about 18% or 17,000 people with shingles will go on to develop a debilitating form of chronic neuropathic pain, Post Herpetic Neuralgia (PHN).

92% of shingles cases occur in older persons with an intact immune system (though somewhat weaker due to aging) and 8% in persons with medical conditions that keep their immune systems from working properly (for example,HIV infection, certain types of cancer and those who receive immunosuppressive therapies as in organ transplant patients, etc).

Although adults of all ages are affected, studies worldwide document that the incidence, severity, and complications of herpes zoster all increase strikingly with advancing age. For instance, the age group with the largest number of herpes zoster cases ranges from 50 to 59 years of age; 68% of herpes zoster cases occur in persons aged 50 years or older and 49% (almost HALF of all cases) in people 60 years or older.

How does shingles manifest itself? In 70%–80% of patients the disease will start with pain and hours to days later a painful blistering rash will show up exactly where pain is. The blisters affect in half of the cases the nerves of the trunk (body) and in 10-25% of the cases the face and particularly the eye area. Neck, low back, buttocks and thighs can also get affected. Unfortunately, the original pain my be mistaken for other conditions like a back sprain or kidney stone, so that precious time may be lost before seeking antiviral treatment (believed to work if given within 3 days from the start of the symptoms).

Unfortunately shingles is associated with many complications. Except PHN that I will describe below, many of those with eye involvement suffer from chronic, recurrent eye disease and vision loss. In a recent population study, 8.1% of patients with eye shingles developed a stroke as opposed to 1.7% of patients in a comparison group. Numerous other complications are also possible, though much less frequent such as encephalitis, pneumonia etc.

In regards to PHN, it is the most feared complication of shingles. It will affect 1 in 5-6 people with shingles and occurs rarely among people under 40 years of age. To put this in prospective  – PHN affects older persons with 83% of the patients being 50 years or older with the majority of cases in individuals aged 60 years and older.Management of PHN is often suboptimal and requires a multifaceted approach as PHN is largely resistant to pharmacologic treatments.

The risk of shingles and PHN cannot be underestimated. Canada faces a significant demographic shift with the proportion of seniors increasing at a rate higher than for any other age group for the first time in the history of the country. It is projected that the population of seniors in Canada will increase from 4.2 million to 9.8 million between 2005 and 2036, so that the seniors’ share of the population is expected to almost double, from 13.2% in 2005 to 24.5% in 2036.

Studies have shown that shingles and PHN affect the sufferer in all 4 health domains: Physical (loss of appetite, weight loss, insomnia, reduced mobility and activity); psychological (depression, anxiety, difficulty concentrating); social (withdrawal, isolation, loss of independence) and functional (personal care, household chores, traveling etc).

Painful shingles requires often strong pain killers on the top of antivirals for the first few days and certain medications for the affected nerves to sooth the intense pain of the rash. Acute complications are hard to treat and may have long term serious effects (such as vision problems and PHN). Unfortunately, once PHN happens, there are no good treatments that can offer most patients meaningful relief.

However, recently, a vaccine was approved by Health Canada. Large studies have shown that it prevents shingles in 51% of patients and PHN in 2/3rds of those with shingles over 60 years of age. When it comes to costs of publically funded treatments, health officials and those who handle the public purse, must consider “cost- effectiveness”. In other words, how much does a new treatment cost, how much benefit it offers and to what kind of populations. Researchers create mathematical models taking numerous factors in account, to advice governments and officials where their money is best spent. Such calculations in a published Canadian study, suggest that vaccination of older individuals between the age of 65 to 75 is the most cost effective.

Irrespective of who pays the bill, you may want to educate yourself and ask your doctor about the value of the vaccine for yourself and your loved ones.


Angela Mailis Gagnon, MD, MSc, FRCPC(PhysMed)

Director, Comprehensive Pain Program,

Senior Investigator, Krembil Neuroscience Centre

Toronto Western Hospital,

Chair ACTION Ontario