Delhi has reported 504 cases of dengue in the last five days, taking the number of patients hit by the mosquito-borne viral disease to 6,486, the highest since 1996.
Data released on Thursday by the Municipal Corporation of Delhi, which tracks the infection the symptoms of which include high fever and aching joints, shows 25 people died of dengue this season. Records of major hospitals, however, put the number of dead at 43.
Unreported cases, too, are much higher, with government hospitals across the Capital confirming more cases than the civic agency.
“This year has been particularly bad because the circulating virus strains 2 and 4 are more deadly, uncontrolled construction and the heavy rains in July compounded the problem,” said Jagdish Prasad, director general of health services, union ministry of health.
There are four genetically distinct viral strains — 1, 2, 3 and 4 — of dengue. Strains 1 and 3 are considered milder.
With 10,252 cases and 423 deaths, 1996 is the worst dengue year on record for Delhi. It saw the government make reporting the viral disease mandatory to prevent and control outbreaks in 18 endemic states/union territories, including Delhi, Kerala, Tamil Nadu, Karnataka, Maharashtra, Rajasthan, Gujarat and Haryana.
Of the total cases reported so far in the city, 5,695 have been reported in the month of September alone.
“Though infection peaks in mid-October and November, the pattern may change if there is no rain,” said Ekta Gupta, additional professor, department of virology, Institute of Liver and Biliary Sciences, New Delhi.
It has been a dry September for Delhi. The city received only 21.8mm of rainfall as opposed to 128.4mm it normally does in the month.
Dengue is transmitted by the bite of Aedes aegypti that breeds in containers with clear and stagnant water.