At least nine people have died after contracting encephalitis, commonly known as “brain fever”, in the northern town of Siliguri in West Bengal since May this year.

“Six of the victims were diagnosed with Acute Encephalitis Syndrome (AES), three others fell to Japanese Encephalitis,” said Nirmal Bera, North Bengal Medical College and Hospital’s Vice Principal and Medical Superintendent.

“The health department is conducting massive clean-up operations and awareness programmes to contain the disease at the earliest,” Bera added.

Encephalitis is a disease that results in inflammation of the brain, affecting the patient’s central nervous system. It can be caused due to bacterial or viral infections of the brain, injection of toxic substances or increased complications of an infectious disease.

While the lesser symptoms include headache and fever, the more severe ones cause the onset of mental problems like seizures, confusion, disorientation, tremors and hallucinations.

Outbreaks of AES and Japanese Encephalitis (JE) are common every year in India, especially during the monsoon season, and claim hundreds of lives. In 2014, 254 people had died of AES and health authorities have warned that more people are at risk this year.

Ten more persons suffering from the disease have been admitted to North Bengal Medical College and Hospital and fresh eight new cases have been reported in the area.

Dr Rudranath Bhattacherjee, chairman, standing committee, health services, West Bengal government said the administration was keeping a close watch on the situation and emergency steps were being taken to contain the outbreak.

“The health department has set up clinics across affected areas and is trying to prevent breeding of mosquitoes by fogging, especially around pig farms, where there is a high risk of contracting the virus,” said Bhattacharyya.

“Hundreds of people are at risk because the state government only firefights encephalitis during the breakout and does not conduct awareness programmes throughout the year. If people are made to follow basic rules of hygiene and ensure that mosquito is not provided breeding ground, so many lives could be saved,” said Pritesh Nandi, a house physician in Siliguri.