Two patients admitted to the North Bengal Medical College and Hospital (NBMCH) died since Saturday night, the facility's superintendent Amarendranath Sarkar said.
A concerned West Bengal government has announced a high alert in the seven North Bengal districts.
North Bengal Development Minister Gautam Deb visited the NBMCH here in Darjeeling district Saturday and met the patients suffering from the Acute Encephalitis Syndrome.
Health officials and ministers will meet at the state government's branch secretariat Uttar Kanya in neighbouring Jalpaiguri district Monday to discuss the sudden outbreak of the disease.
Appealing to the people to remain alert and take necessary precautions, Deb said a separate fever clinic has been set up at the NBMCH for the outdoor patients.
Sarkar said this year 320 patients have so far been admitted to the NBMCH with Acute Encephalitis Syndrome. Of them, at least 80 have died. The figure includes 15 who died of confirmed cases of Japanese Encephalitis.
Encephalitis is a disease that results in inflammation of the brain. The patient's central nervous system is affected. While the lesser symptoms include headaches and fevers, the more severe ones cause the onset of mental issues like seizures, confusion, disorientation, tremors and hallucinations.
It can be caused due to bacterial or viral infections of the brain, injection of toxic substances or increased complications of an infectious disease.