Global Health Burden of Herpes Zoster Will Likely Increase

Since the risk of herpes zoster (HZ) rises sharply after age 50, the significant global health burden of shingles pain is expected to increase as the population ages.

In a comprehensive literature review published in the June 10, 2014, edition of BMJ Open, Kosuke Kawai of the Harvard University School of Public Health, and associates analyzed the incidence rates and temporal trends of HZ, as well as the risk of complications — including postherpetic neuralgia (PHN) and HZ-associated hospitalization — and mortality in the general population.

After searching PubMed, EMBASE, and the World Health Organization (WHO) library through December 2013, the researchers included a total of 130 studies conducted in 26 countries in their systematic review, which was funded by Merck & Co.

While the HZ incidence rate ranged between 3 and 5 per 1,000 person-years in North America, Europe, and Asian-Pacific countries, there was a scarcity of data from other regions. Over the past several decades, a temporal increase in the incidence of HZ was reported across 7 countries, often occurring before the introduction of varicella zoster virus (VZV) vaccination programs.

According to the study authors, the risk of developing PHN varied from 5% to >30%. More than 30% of patients with PHN experienced persistent pain for at least one year.

The risk of HZ recurrence ranged from 1-6%, though long-term follow-up studies reported higher risks. Hospitalization rates ranged from 2 to 25 per 100,000 person-years, with higher rates seen among elderly populations.

Because the quality of the examined studies varied widely, the investigators could not synthesize their data quantitatively; thus, they called for future research with more rigorous methods. Additionally, the researchers recommended that healthcare providers and policymakers consider implementing worldwide preventive measures, such as vaccination against VZV.