Associations between Dengue Hospitalizations and Climate in Can Tho, Vietnam, 2001-2011

Abstract

In Vietnam, dengue fever is a major cause of hospitalization with over one million cases reported between 1991 and 2004. Changes in the incidence of dengue in Can Tho city due to increased temperature and changes in precipitation, are anticipated. In an effort to better characterize the relationship between climate and dengue, we examine the associations between weather variables and dengue hospitalizations in Can Tho between 2001 and 2011. Monthly data on hospitalized dengue cases and means of temperature, rainfall and humidity were recorded from 2001 to 2011. We used the Box-Jenkins approach to modelling of time series to assess the association between these factors. This model was validated by the Portmanteau test. Our results revealed that the highest dengue incidences in Can Tho occur between July and December. After adjusting for seasonality, the rate of dengue hospitalizations was significantly associated with relative humidity with a lag of one month. Rainfall and temperature were not predictors of dengue hospitalization rate. In conclusion, these data suggest that maximum relative humidity (with a one month lag) is an important determinant of dengue hospitalizations. Enhanced vector control during months with high humidity may be an important approach to prevent dengue transmission.

Keywords

• dengue fever
• incidence
• climate
• hospitalizations
• ARIMA model