Assam was put on high alert after cholera claimed four lives and took seven districts in its grip, officials said Friday.
More than 500 people have fallen sick in the state.
Sources in the National Rural Health Mission (NRHM) said Sivsagar, Darrang and Cachar districts have been identified as the worst affected.
"We have formed Rapid Response Teams (RRTs) in each district to control the spread of the disease," said an official.
While two people died in Sivsagar, the other two deaths took place in Darrang and Cachar districts.
Jorhat, Golaghat, Dibrugarh and Sonitpur districts have been put on alert.