At least 65 people have died in an outbreak of the epidemic of diarrhoea and cholera in the past two months in Assam and hundreds have been affected.
A health department official said the worst hit areas are parts of Jorhat, Golaghat, Sivasagar and Nagaon in eastern Assam. Most cases were reported from tea garden areas.
"In some areas, particularly in Golaghat, water supplied by the municipal board was found to be contaminated with e-coli," Assam Health Minister Himanta Biswa Sarma said.
In some areas, laboratory tests on patients suffering from diarrhoea found strain of cholera. Authorities, however, said the strain was not 'very virulent' and there was no need to panic.
"The disease is spreading mostly in tea gardens and it is primarily due to lack of basic hygiene, non-availability of clean drinking water and poor sanitation. The garden managements should provide these amenities to their workers," said a health department official.
The Assam health department has sounded a general alert and launched a massive cleanliness drive including distribution of water purifying tablets in affected areas.
"All precautionary measures were being taken and the patients provided with the best of medical care," the minister said.
In its most severe forms, cholera can be fatal. A healthy person may die within two to three hours of the onset of symptoms.
The symptoms include those of general stomach upset and massive watery diarrhoea, including terrible muscle and stomach cramps, vomiting and fever.
Cholera is transmitted through ingestion of faeces contaminated water loaded with the cholera bacterium.