Epidemiology of Drowning Death Identified from Flood - Related Surveillance during the Worst Flood in Thailand, August 2011 - January 2012

Background : The flood in 2011 was one of the most severe floods in Thailand and affected all regions especially in northern and central part of the country. It caused severe damage with substantial number of injuries and deaths during flood for many months. The main cause of deaths was drowning, which accounted for 83.24% of all flood-related fatalities. Methods : The Bureau of Epidemiology, Department of Disease Control had conducted mortality surveillance during this severe flood, between August 2011 to January 2012, to study magnitude of problem and cause of death. This study focused on death from drowning due to its high magnitude and complexity of the problem. Results : During the study period, there were 899 reported fatalities due to drowning. Age ranged between 23 days to 98 years old, with median 48 years. Male to female ratio was 3.73 : 1. Drowning fatalities were reported from all regions, with disproportionately high in central and northern region. The highest number of drowning deaths was reported in October. When excluded the people who had unknown cause of death, 5 most common cause of drowning fatalities were fishing (12.35%), boating (9.79%), alcohol drunken (9.01%), falling inside the house (8.57%) and fainting (7.12%). Conclusions : Rapidity of current and level of flood also related with cause of drowning fatalities. In areas where the flood level was not so high, one main cause of death was walking or riding motorcycles through rapid water and got wash by strong current, especially while crossing canal or river. For areas that flood level was very high, boat overturns became one of the main fatality cause. However, when considering overall picture at each level of flooding, fishing were the highest cause of death for each flood level, except in very urban area like Bangkok and its vicinity where fainting and falling inside the house were the most common causes of death. Therefore, information about cause of drowning fatality during flood by context of area and degree of flooding would be useful for prevention of future deaths from similar situation.