Cases of dengue are being reported from across Calcutta and Salt Lake despite claims of “intensive drives” by the civic bodies to contain the disease.

Two cases of dengue were confirmed in Salt Lake on Tuesday, taking the number of residents afflicted with the disease over the past week to four.

Nilaj Chakraborty, 18, a resident of FE block, was admitted to AMRI Hospitals with dengue symptoms on Monday. “Blood tests confirmed dengue on Thursday,” said Nandagopal Bhattacharya, the chairman-in-council (health) of Bidhannagar Municipality.

Nilaj’s sister Satarina, 21, had tested positive for dengue a week ago and was admitted to the hospital. Sudhangshu Pandey, a resident of the same block, was admitted to hospital on Monday with dengue.

Another patient, A. Sengupta of Purbachal housing estate, was admitted to Apollo Gleneagles Hospitals four days ago. “Tests confirmed that he was suffering from dengue. His gums were bleeding and platelet count was very low,” said Milan Chhetri, a consultant of internal medicine of the hospital. “Two patients with malaria have been admitted.”

Chairman-in-council Bhattacharya said civic officials had visited FE block and sprayed mosquito repellent. “We are not sure whether these people had contracted the disease in Salt Lake or in the Calcutta municipal area.”

In Calcutta, several cases of dengue have been reported over the past month, though civic officials claimed the number was less than last year. “Since January, only 12 cases have been reported. None died,” an official said.

Sources said quite a few patients have tested positive for dengue in various private hospitals. “A woman from south Calcutta was admitted to a private hospital with fever, body ache and skin rashes. Tests confirmed that she had dengue. Her husband, too, is suffering from similar symptoms,” said critical care expert Subrata Maitra.

Amitabha Nandi, the director of the Centre for Tropical Medicine and Parasitology, said three patients, two from south Calcutta and one from Howrah, tested positive in his clinic in August.

Civic officials claimed they had launched an awareness campaign on dengue.