Six persons were on Friday admitted to hospitals in the district and the Medical College Hospital, Kozhikode, with symptoms of cholera.
The cases were reported from the tribal colonies at Muttil grama panchayat.
It is suspected that a tribesman at the Anpathammile colony, near Muttil, who died on Thursday, might have suffered from cholera.
Though the reason for the death was yet to be ascertained, cases with similar symptoms were being considered cholera after the district was declared a cholera endemic area, A. Sameera, District Medical Officer, said.
Dearth of safe drinking water, lifestyle and food habits of the tribesmen, and lack of proper sanitation facilities at many tribal colonies were the reasons for the spread of the disease, she added.
There was a cholera epidemic in Mysore recently and it was suspected that the disease might have spread from the tribal workers who were working in the ginger plantations there, she said. Similar incidents had been reported in the past two years in the district, Dr. Sameera said.
Field activities had been intensified and measures taken to combat the disease, she added.