"A maximum alert has been sounded across Assam and medical teams are working on a war footing to check the spread of malaria," Assam Health Minister Bhumidhar Barman told IANS.
Most of the casualties were reported from the eastern Assam districts of Golaghat and Lakhimpur, besides from areas bordering Bhutan.
"Some 35 people have died of malaria in the past few days and an estimated 20,000 people are hit by the disease," the minister said. Unofficial reports put the death toll in the malaria epidemic at around 80.
Experts say early monsoons had led to the outbreak of the mosquito-borne disease.
"The early monsoon apart, what is worrying us is that anti-malaria drugs like chloroquine are not working with those affected showing signs of resistance," Barman said.
Authorities in Assam have alerted the Indian health ministry to rush stocks of 'rapid diagnostic kits' required for instant blood sampling to detect malaria.
"We have already rushed several mobile medical teams to vulnerable areas, besides trying out alternative anti-malaria drugs to check the disease from getting malignant," the minister said.
Doctors say the initial symptoms of malaria are high fever and cold, and at times loose motions and stomach pain.
"Villagers often bring the patients to hospitals very late when chances of survival are very remote. There is still a great deal of ignorance about the fatal consequences of malaria," Dharni Bora, a doctor in the worst-hit Golaghat district, said over the phone.
India's northeast region is a known "malaria zone" with the disease claiming an estimated 500 lives annually.
At least 6,000 health workers, including doctors and paramedics, are being rushed to malaria-prone areas to prevent the disease from spreading. "Spraying of disinfectants and fumigation are being done to kill mosquitoes across the state," the minister said.
Government authorities are worried the disease might spread among hundreds of Indian troops deployed along the India-Bhutan border for counter-insurgency operations.
"We are providing soldiers with specially designed medicated mosquito nets and insect repellents as a precaution against malaria," an army commander said.
During the past five years, at least 50 army and paramilitary troopers have died of malaria in Assam.