Inspite of awareness and cleanliness drives, dengue continued to spread with the death toll touching 99 on Saturday across the country. About 138 fresh cases were reported, raising the number of those who have been afflicted to 4875.

Delhi reported one more death with a woman passing away overnight at the All India Institute of Medical Sciences, where maximum number of cases of the mosquito-borne infection are being treated.

Another person has died in West Bengal, increasing the toll there to four.

As many as 95 new cases of dengue were admitted in various hospitals, including 39 at AIIMS. The total number of patients under treatment at AIIMS at present is 165, its spokesman Shakti Gupta said.

The national capital has reported the highest number of 1373 dengue patients. Besides Delhi, 43 fresh cases of the infection were reported from across the country, National Vector Borne Disease Control Programme said, maintaining that the total number of cases reported so far was 4875.

The disease has affected at least 16 states.

Union Health Secretary Prasanna Hota said the number of those affected by dengue was far less than previous years.

"The nature of the virus (causing dengue) is milder this time," Hota said after a function in Chandigarh.

Dengue death toll so far has been 28 in Delhi, 22 in Maharastra, ten each in Rajasthan and Uttar Pradesh, seven in Karnataka, five in Andhra Pradesh, four in Kerala [Images] and West Bengal, three each in Punjab and Gujarat, one each in Haryana, Tamil Nadu and Madhya Pradesh.

Besides Delhi, 794 cases of dengue have been detected in Kerala, 456 cases in Rajasthan, 441 in Gujarat, 429 in West Bengal, 349 in Uttar Pradesh, 307 in Tamil Nadu, 250 in Punjab, 240 in Maharashtra, 113 in Haryana, 90 in Karnataka and 33 in Andhra Pradesh.

The other affected states include Bihar, Uttaranchal, Madhya Pradesh and Jammu and Kashmir [Images].

In 1996, when the first major outbreak of dengue occurred, 423 deaths and 10,252 cases were reported from Delhi and its neighbouring states.

In another big outbreak in 2003, 215 lost their lives and 12,754 people were affected by the infection.

In Delhi, despite the intensive fogging and fumigation drive, several parts of the central zone, mostly along the banks of river Yamuna, continued to report a high number of dengue cases.

"Large-scale construction activity is being carried out in parts of the central zone, which has led to open sewers -- fertile breeding grounds for the Aedes mosquito," said Municipal Health Officer N K Yadav, who toured the area.

Another problem of the area was irregular water supply at unauthorised contruction sites, which led to storage of water causing mosquito spread.