Shingles caused by chicken pox virus on rise: study

A large-scale survey conducted over a 10-year period has found a 26 percent rise in the incidence of shingles caused by the same virus responsible for chicken pox.

The study, considered unprecedented in scale and carried out in Miyazaki Prefecture, involved 46 medical institutions, including hospitals run by dermatologists, universities and general hospitals.

Members of the prefecture's dermatologist association, including Nozomu Toyama, director of Toyama dermatology clinic, and Kimiyasu Shiraki, professor of virology at the University of Toyama, took part in the survey, which started in 1997 and lasted until 2006.

They analyzed about 48,000 people diagnosed as having shingles triggered by the varicella zoster virus, the same virus that causes chicken pox. The disease is an acute inflammation of the nerve ganglia, the masses of nerve cells that transmit impulses.

Toyama said Miyazaki's population dropped by about 28,000 during the 10-year period but the number of patients verified as having shingles grew 23 percent. He added that the aggregate incidence of shingles sufferers in terms of the number of patients per 1,000 people totaled 4.15, which marked an increase of 26 percent during the decade.

By age, the figure reached the first high point among those in their teens and dropped among people in their 30s. However, it soared among those in their 50s to peak at 7.84 per 1,000 people among those in their 70s.

The age of patients examined ranged from a 3-month-old to a 102-year-old. The incidence among those 10 years old or younger stood at 2.45, indicating it was not rare for small children to be stricken with the disease. This tendency remained unchanged while the study was under way.

The highest number of patients was recorded in August, while the figure sharply plunged during the winter.

The study confirmed past research that the incidence of shingles declined when people had increased chances of coming into contact with children who have chicken pox.

But VZV lies dormant in children's nerves even after they shake off the infectious disease.

The survey also revealed the incidence of shingles was 25 percent higher in women on average than men, with those in their 40s to 60s — centering on those in their 50s — sharply surpassing the rate for men.