The woman, hailing from Bengaluru, had come to the house of her relatives in nearby Coonoor and was suffering from fever for the last three days and was taken to the Government Hospital at Coonoor yesterday.
Suspecting that she was suffering from dengue after preliminary tests, the doctors referred her to Government Hospital here.
Her blood samples taken last evening tested dengue positive today and she was kept in an isolated ward, with a doctor and nurse attending to her, hospital sources said.
Meanwhile, a medical team has gone to Coonoor to test the family members of the woman there, they said.