Epidemiology and Infection

Climate and weather

Meteorological factors and El Niño Southern Oscillation are independently associated with dengue infections

A. EARNESTa1a2 c1, S. B. TANa1a3 and A. WILDER-SMITHa4

a1 Centre for Quantitative Medicine, Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore

a2 Clinical Research Unit, Tan Tock Seng Hospital, Singapore

a3 Singapore Clinical Research Institute, Singapore

a4 Institute of Public Health, University of Heidelberg, Germany


Our objective was to determine the association between temperature, humidity, rainfall and dengue activity in Singapore, after taking into account lag periods as well as long-term climate variability such as the El Niño Southern Oscillation Index (SOI). We used a Poisson model which allowed for autocorrelation and overdispersion in the data. We found weekly mean temperature and mean relative humidity as well as SOI to be significantly and independently associated with dengue notifications. There was an interaction effect by periods of dengue outbreaks, but periods where El Niño was present did not moderate the relationship between humidity and temperature with dengue notifications. Our results help to understand the temporal trends of dengue in Singapore, and further reinforce the findings that meteorological factors are important in the epidemiology of dengue.

(Accepted August 22 2011)

(Online publication September 12 2011)


c1 Author for correspondence: Dr A. Earnest, Office of Clinical Sciences, Duke-NUS Graduate Medical School Singapore, 8 College Road, Singapore (169857). (Email: arul_earnest@hotmail.com)