The impacts of ambient temperature and ultraviolet radiation on the incidence of herpes zoster: An ecological study in Taiwan.

ABSTRACT

The aim of the study was to examine the relationship between ambient temperature, ultraviolet radiation, and the development of herpes zoster in Taiwan. An ecological study was conducted to analyse the database of the Taiwan National Health Insurance Programme. Participants aged ≥20 years with newly diagnosed herpes zoster between 2003 and 2012 were selected for analysis. The monthly incidence rate of herpes zoster was measured between 2003 and 2012. Monthly average ambient temperature in Celsius (°C) between 2003 and 2012 was measured according to the official database of the Central Weather Bureau in Taiwan. Monthly accumulated ultraviolet radiation (MJ m-2 ) between 2003 and 2012 was measured according to the official database of the Environmental Protection Administration in Taiwan. The overall incidence rates of herpes zoster ranged from 2.54 to 5.67 per 10 000 persons per month from 2003 to 2012.The monthly average ambient temperature was higher and the monthly accumulated ultraviolet radiation was stronger from May to October. The incidence rates of herpes zoster seemed to be high during the period of high ambient temperature and strong ultraviolet radiation (from May to October).Whenever ambient temperature increased 1°C per month, the incidence rate of herpes zoster increased by 0.072 per 10,000 persons per month. Whenever ultraviolet radiation increased 1 MJ m-2 per month, the incidence rate of herpes zoster increased by 0.313 per 10 000 persons per month. There is a significant association between ambient temperature, ultraviolet radiation, and the development of herpes zoster in Taiwan. The incidence rate of herpes zoster is high during the period of high ambient temperature and strong ultraviolet radiation. Low ambient temperature and weak ultraviolet radiation might be beneficial for the prevention of herpes zoster.