Institution of a rapid surveillance system controlled major Cholera epidemics in Aila flood affected Sundarban, West Bengal, India, 2009.

Background: On 25th May 2009 cyclone Aila hit Sundarban reverian area of South 24 Parganas district in west Bengal, India. It demolished 400 km river bank and resulted flood in nine coastal blocks affecting 2.5 million populations and rendering 0.87 million people homeless. About 50,000 people were rescued in 263 camps. We immediately instituted a rapid surveillance system with objectives to control diarrhea diseases, identify and prevent major outbreaks.

Method: Medical team visited rescue camps and treated minor ailments including diarrhea. We started active and stimulated passive surveillance from 26th May and daily reporting through mobile phone. We prepared epi-curve for each block and identified outbreaks. We collected Stool and water samples and examined for pathogens.

Result: About 37% (365/997) villages were affected and 59,620 diarrhea patients (attack rate 23.8/1000) were identified from 26/5/09 to 13/8/09 with 23 deaths (case fatality ratio 0.04%). We found V. Cholerae el-tor ogawa in 30 samples from four blocks, and coliform in water samples. The epi-curve started on 26th May, reached a peak in all the blocks within 28/5 to 4/6, subsided within a week and touched baseline by the end of June09. There was scarcity of safe drinking water due to contamination of sub-merged tube-wells and surface water by flood.

Conclusion: We disinfected water sources repeatedly, supplied three million halogen tablets and drinking water in poly pouch. We educated people to chlorinate water properly and maintain hygiene. We ensured prompt treatment and distributed 12 million packets ORS. We controlled the epidemic successfully without a second peak. We recommended lifting of the tube-well to 8-10 feet height from the ground with arrangement of stair case and concrete platform to protect contamination during flood.

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Author (s): 

Authors:Ajay K. Chakraborty, R. Ramachandran, M. V. Murhekar National Institute of Epidemiology, Indian Council of Medical Research, Chennai, India. Phone: +91-44-26136420 Fax: 91-44-26820464.

Presenter (s): 
Dr. Ajay Chakraborty
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