Three cases of chikungunya were detected in Salt Lake on Sunday, taking the number of people affected by the disease in the township to 15.

The three new cases were detected at Nazrul Pally, in Polenite, in Salt Lake’s ward 14. The other 12 cases were also detected there.

District health officials said the tests on blood samples were conducted at School of Tropical Medicine.

“The actual number of people suffering from chikungunya in the area is likely to be much higher. A majority of the residents suffering from high fever do not carry out a blood test,” said a health department official.

“Three new cases of chikungunya have been detected,” confirmed K.K. Adhikary, the chief medical health officer of North 24-Parganas. According to him, more than 2.5 lakh people in the district suffered from chikungunya and other types of viral fever in the past year.

On Saturday, a team of district health officials visited Polenite to assess the situation. A meeting was held between officials of the district health department and Bidhannagar Municipality on Sunday.

The sub-divisional officer of Bidhannagar, Tapas Chowdhury, said: “We are taking measures to stop the spread of the virus to other parts of the added areas and the township proper. A medical team will again be sent to Polenite on Monday.”

Chemicals to kill mosquito larvae were being sprayed and paracetamol tablets were being distributed in areas where chikungunya has been detected, claimed Chowdhury.