Risk Assessment and Impact of Floods on the Transmission of Vector Borne Diseases

Floods are the result of natural disasters in an area due to prolonged continued and heavy rains and are frequently followed by a proliferation of mosquitoes due to the creation of a large number of breeding habitats. In the endemic zones for VBDs, vector mosquito species require special attention for planning immediate control measures as these areas may pose a threat to public health. Natural disasters continue to strike unabated, flash floods due to heavy rains, riverine floods,coastal floods and cloud burst floods. In general, floods are witnessed due to the concentrated spells of heavy rains during the monsoon months and seasonal disturbances. The low lying areas are submerged under water and remain water logged for a long duration. Slowly, the low lying water bodies thus created after receding of flood water, act as a breeding potential source for the vector mosquitoes. Some of the areas receive water from flushing of water from high altitude areas due to heavy rains or melting of ice. There is definite need for public health preparedness and response for the flood affected areas to reduce the transmission of VBDs with proper risk assessment. There are chances for the onset of transmission of VBDs to the population shifted to temporary shelter homes away from homes. Given the situation with the presence of congenial conditions owing to presence of favourable climatic variables for propagation of vectors, pathogens and susceptible population, there are chances of disease outbreaks. Therefore, the risk assessment of the flood affected area with the vulnerable population is essential to make preparedness and response to any onset of VBDs transmission. Disease and vector surveillance are the key elements to be in place for such flood affected areas during and after the floods.