Fifteen more persons with suspected dengue fever have been admitted to hospitals in Chennai, Madurai and Coimbatore districts even as health authorities carried out fogging and spraying operations to contain the spread of the disease.

In Chennai, three more cases were reported taking the total number of cases detected in the city to 129 this year. Health officials said that the patients were responding to treatment. Screening camps have been organised at major railway stations as the authorities were worried that people from the southern region coming to city could be bringing the virus along with them.

In Madurai, seven new dengue positive patients were admitted to the Government Rajaji Hospital (GRH) on Saturday.

Dr A Pragadeshwaran, Resident Medical Officer (RMO), GRH, said one of the patients was from Madurai district while the others were from neighbouring Theni and Virudhunagar districts.

The RMO said that all the patients were stable and they were recovering well from dengue.

Meanwhile, Madurai Mayor V V Rajan Chellappa and Corporation Commissioner R. Nanthagopal visited a few areas, including Subramaniyapuram, Mela Anuppanadi Housing Board, Ellis Nagar and Sellur Market, where fogging and spraying were being done to control the dengue causing mosquito.

The scene is not very different in Coimbatore where, despite claims of adequate preventive measures by health authorities, five more persons with symptoms of dengue have been admitted to the Coimbatore Medical College Hospital in the past two days.

With this, sources said, there were seven person undergoing treatment at the hospital for the deadly viral infection.

One patient was from the city and the rest from neighbouring districts. Four of the cases were from the Tirupur district while Erode and Karur districts have accounted for one case each.

Strikingly, most of the admitted persons were in the age group of 16 to 28 years.

"Fever, coupled with headache, especially beneath the eyes, and pain in the bones are the early symptoms of dengue," said P Ravi Kumar of Coimbatore Medical College Hospital.

"People should go for a blood test immediately after they betray such symptoms for early detection," Ravi Kumar added.

Health officials said prevention of water stagnation was of paramount importance to preventing the spread of the disease.

"Aedes aegypti mosquitoes breed only in fresh water and spread disease only during the day time," said Deputy Director of Public Health, S Senthilkumar.

"People should make sure that there is no water stagnation around their houses. Even a disposed water cup could be a source for the mosquitoes to breed," Senthilkumar added.

Meanwhile, the city corporation has started fogging operations in areas prone to acute mosquito breeding.