Epidemiology and Infection

Childhood infection

Effect of weather variability on the incidence of mumps in children: a time-series analysis

D. ONOZUKAa1 c1 and M. HASHIZUMEa2

a1 Department of Planning Information and Administration, Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan

a2 Department of International Health, Institute of Tropical Medicine (NEKKEN) and the Global Center of Excellence program, Nagasaki University, Nagasaki, Japan

SUMMARY

The increasing international interest in the potential health effects of climate change has emphasized the importance of investigations into the relationship between weather variability and infectious diseases. However, few studies have examined the impact of weather variability on mumps in children, despite the fact that children are considered particularly vulnerable to climate change. We acquired data about cases of mumps in children aged <15 years and weather variability in Fukuoka, Japan from 2000 to 2008, and then used time-series analyses to assess how weather variability affected mumps cases, adjusting for seasonal variations, inter-annual variations, and temporal variations of two large epidemics in 2001 and 2004–2005. The weekly number of mumps cases increased by 7·5% (95% CI 4·0–11·1) for every 1°C increase in average temperature and by 1·4% (95% CI 0·5–2·4) for every 1% increase in relative humidity. The percentage increase was greatest in the 0–4 years age group and tended to decrease with increasing age. The number of mumps cases in children increased significantly with increased average temperature and relative humidity.

(Accepted December 06 2010)

(Online publication January 07 2011)

Correspondence:

c1 Author for correspondence: Dr D. Onozuka, Department of Planning Information and Administration, Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135, Japan. (Email: onozuka@fihes.pref.fukuoka.jp)

Metrics