The dengue count in Calcutta is on the rise, with the south and southeastern reaches causing most concern.

The daily dengue report prepared by the School of Tropical Medicine (STM) for the health secretary on Thursday stated that of the 15 people tested, five had been found to be carrying the virus.

Civic officials claimed that two cases of dengue had been detected during the day. Shatadru Das, 10, a resident of Panditiya Road, is the last to be found infected. He was admitted to a private hospital in Dhakuria. In the evening, the civic health department put the number of infections at 29.

According to reports from civic clinics and hospitals, larvae of the Aedes egypti mosquito, which causes dengue, are most prevalent in water samples drawn from Prince Anwar Shah Road, Dhakuria, Lake Gardens and Golf Green. The samples collected at Topsia, Tiljala and along EM Bypass have also revealed Aedes larvae.

“Following the death of a youth due to dengue, we had carried out a survey on and around Prince Anwar Shah Road, particularly in wards 93 and 94, in July. Mosquito larvae were found in the area. We undertook an awareness drive but it didn’t prove effective,” said a senior official of the STM entomology department.

“Unlike last time, those who tested positive in our clinic are from the city itself. It is not that people are bringing dengue from outside. The infection is here,” asserted STM director D.K. Neogy.

The Lakshmi puja holiday of the civic health department staff has been cancelled to battle the spread of dengue. Two mobile clinics will do the rounds to collect blood samples.

The civic health clinics and dispensaries will stay open on Friday. Chief municipal health officer Deb Dwaipayan Chattopadhyay has been asked to re-activate the health management information system.

“All departments concerned have been put on alert,” said state director of health services K.C. Barui.