Jamshedpur, Sept. 20: Cases of dengue fever have touched a seven-year high in Jamshedpur, with 362 people being hospitalised till date compared to only 59 in the neighbouring districts of West Singhbhum and Seraikela-Kharsawan combined, and this despite claims of determined efforts to check the scourge.

Public health experts warn that the torment isn't over yet since the virus is usually in its most endemic phase at the fag end of the monsoon, which officially has another 15 days to go.

Government epidemiologist Dr Praveen Kumar Karn on Monday told this correspondent that they suspected that the growing number of abandoned quarters and the gardening culture of a migratory population were among the key reasons behind the outbreak.

"We have shared our findings with the state health department and (East Singhbhum) district administration. In our survey, we found a large number of abandoned company (Tata Steel and others) quarters, whose drains are not properly maintained and most of whose overhead tanks have broken covers," he said.

On August 11, The Telegraph had incidentally highlighted the threat posed by over 2,000 abandoned quarters across the steel city whose open tanks and pots were breeding the dengue-causing Aedes aegypti mosquito. The number has increased by 50 per cent in two years, said a source in Jusco's town division.

"The Aedes can breed even in a broken cup or the surface of a drum after a brief spell of rain. Such vector breeding spots, which exist in thousands, can easily go undetected even by designated health teams," Dr Karn said over phone from Ranchi, indicating loopholes in civic surveys.

According to the health expert, the dengue mosquito can fly up to a distance of three metres and poorly maintained flower pots, lawns and gardens helped them thrive in homes.

"Unlike other cities and towns in the state, we noticed that Jamshedpur residents have a fetish for flowers and greenery. But, if not maintained, these turn into breeding spots during the rains," the epidemiologist said, sharing his July-August study in the city.

Jamshedpur's floating population is also being considered a reason behind the virus attack. "A large number of visitors from other states, especially from western and southern India, come to this industrial and cosmopolitan city. Some may be transmitting the virus through mosquito bites," said the doctor.

District officer for integrated disease surveillance Dr Sahir Pall, however, refused to put the onus of the dengue outbreak on under-performing civic bodies.

"All the urban local bodies are carrying out fogging and spraying of larvicides. Our teams are going door-to-door in localities from where dengue positive cases have been reported to destroy breeding spots. We will starting fining individual offenders," he said.

Jusco entomologist Dr Alok Suman gave a vague reason why the dengue virus was thriving better this time. "The female Aedes bites during the daytime. It is easily spotted and swatted away before it can suck enough blood to fill its stomach. So, it bites many people at a time," he said without clarifying how that affected the annual statistics.