Impact of meteorological components on diarreal diseases in Bangladesh

The northeastern regions of the Indian subcontinent including Assam and Meghalaya in India and Bangladesh are one of the heaviest rainfall region in the world. Cherrapunji, original name Sohra has the world record of annual rainfall of 26,461mm between August of 1860 and July of 1861. The mean annual rainfall of 11,252mm was recorded for 105 years from 1901 to 2006. The temporal scale of the rainfall includes the various periods; annual, seasonal, intraseasonal and daily variations. Roughly speaking, four main seasons are pre-monsoon season from March to May, monsoon (rainy) season from June to September, post-monsoon season in October and November, and winter from December to February. Two phases of active and break periods are clearly recognized in the monsoon season. The periodical variation can be detected with ten days to two weeks. Rainfall in the night time is prominent. These heavy rainfall amount flows down to Bangladesh directly and cause the serious floods almost every year. Diarrheal disease remains a remarkable factor that causes significant mortality annually, especially in developing countries. It is also anticipated that the global warming may further accelerate the increasing trend of epidemics in near future. Thus, it becomes more and more important to clarify the dynamics that control the epidemic of diarrheal diseases. We aim to assess the impact of local climatic variability on diarrheal diseases on the basis of the data of long term meteorological data of Bangladesh Meteorological Department and diarrheal surveillance data used were daily diarrheal patient numbers from ICDDR,B(International Centre of Dirroreal Disease Research, Bangaldesh) Hospital for over 22 years (1980-2001). Time scales of meteorological elements used were diurnal, intra-seasonal, seasonal and inter-annual variations. Lag-correlation and time-series regression models were used to assess an effect of meteorological phenomenon on the epidemiology of diarrheal diseases.