Epidemiology, 2005; 16(5): S60.
Aim: The objective of this study was to investigate the seasonal pattern of admissions and emergency room (ER) presentations for diarrhoeal disease in children, and their association with climatic factors such as temperature and humidity. Back to Top | Article Outline Methods: Monthly hospital admissions (July 1992 to June 2003) and ER presentations (July 1998 to June 2003) for diarrhoea in children (< 5 years) were aggregated in Canberra, Australia. Log-linear models describing monthly hospitalisations for diarrhoea, in terms of calendar time and the current and previous month’s average temperatures and dew point average (a measure of humidity), were fitted for hospitalisations and ER presentations. A negative binomial chance model was used to accommodate over-dispersion in the counts. The admissions and ER presentations for the previous month were also included in the models. Back to Top | Article Outline Results: Diarrhoeal admissions comprised 4.3% of admissions and 5.3% of ER presentations. The rates of hospital admissions and ER presentations for diarrhoea fluctuated over the study period. Children younger than two years of age comprised 64% and 62% of all children’s (<5 years) diarrhoeal admissions and ER presentations, respectively. Admissions and ER presentations peaked in winter and spring and were lowest in summer. The most pronounced seasonal patterns were observed among children younger than two years of age. The difference between summer and spring admissions and ER presentations were 153% and 146% respectively. An increase in temperature of the previous month was significantly associated with a decrease in diarrhoeal admissions, while a decrease in temperature of the current month and humidity of the previous month were associated with a decrease in ER presentations. These factors were significant even when adjusted for season in the model. There was a significant interaction between temperature and season for hospitalisations and ER presentations. This analysis will be extended to two other cities in Australia. Back to Top | Article Outline Conclusion: This study demonstrates an association between climatic factors and diarrhoeal admissions and ER presentations. The lag of one month suggests that temperature may be influential, earlier, for hospitalisations. The winter and spring peaks observed for children less than two years of age presenting to the ER and being admitted to hospital suggest rotavirus as the possible aetiology for a large proportion of these cases. There may be differences in the aetiology of some ER presentations compared to hospital admissions. Climatic factors such as humidity in the previous month, for example, may be associated with some of the ER presentations observed. Understanding the links between climatic factors and diarrhoeal disease in children and given the predictable nature of excess diarrhoeal admissions and ER presentations in winter and spring, demands on health service needs could be forecasted. This would facilitate the appropriate real-location of hospital resources in terms of staff and hospital beds to prepare for seasonal fluctuations in cases. This study will be presented at the Symposium on “Climate, weather and enteric disease”.