Jobath A. Sangma, who had tested positive for Acute Encephalitis Syndrome, passed away at his residence in West Garo Hills district, District Magistrate Ram Singh told IANS.
"Sangma was working as National Rural Livelihood Mission cluster coordinator in Rongra, South Garo Hills district, where he must have got infected," Singh said.
Health Department officials said the first case of a patient dying of Japanese Encephalitis, which is also known as brain fever, was first reported in May. The second death took place in June, while two people have died this month.
As many as 66 people - 47 in Garo Hills and 19 in Khasi Hills - have tested positive till July 24, a Health Department official told IANS.
Health and Family Welfare Minister A.L. Hek said he had directed hospital authorities to provide adequate treatment and medicines to those suffering from the disease.
Chief Minister Conrad Sangma had last month reviewed precautionary measures being undertaken by the departments concerned to prevent the spread of the disease.
Caused by a mosquito-borne virus, encephalitis results in inflammation of the brain and affects the central nervous system. While the lesser symptoms include headache and fever, the more severe ones cause seizures, confusion, disorientation, tremors, and hallucinations.