The capital has a very high presence of Aedes mosquitoes that transmit viral diseases like dengue and chikungunya, posing a serious health threat.
A new government survey has found that some 52 percent of containers -- plastic barrels, buckets, clay pots, used or abandoned tyres and tubes, water tanks and so on -- have larva or pupae of this mosquito in them.
Their presence in over 20 percent of such containers is considered risky.
The survey was done during June 1-5 by the Communicable Disease Control (CDC) unit of the Directorate General of Health Services (DGHS).
Forty-seven of the 53 areas surveyed under the two Dhaka city corporations has a very high presence of Aedes mosquitoes, DGHS Director Prof Sanya Tahmina told The Daily Star.
Dhanmondi, Shahbagh, Azimpur, Mitford, Banasree, Gendaria, Siddeshwari, Green Road, Hossaini Dalan, Wari, Bailey Road, Gopibagh, Kalabagan, Lalbagh, Madartek and Dholpur were found to be riskier than the other areas of Dhaka South City Corporation.
In Dhaka North City Corporation, Uttara-9, Moddho Badda, Gulshan-1, Lalmatia, Pallabi, Moghbazar Chowdhurypara, Rampura, Tejgaon and Banani have higher presence of the mosquito.
The findings go with the high number of chikungunya and dengue cases this year.
According to the DGHS control room, 378 dengue cases have been reported between January 1 and June 15. During the same period, the Institute of Epidemiology, Disease Control and Research (IEDCR) has found about 400 cases of chikungunya.
The DGHS, which began recording chikungunya cases since June 1, received reports of 228 cases till yesterday from different hospitals in the capital.
"We are hearing that many people are contracting chikungunya. And not everyone goes to doctors unless it is very severe," said Prof Sanya, who also leads the CDC.
Chikungunya had been sporadic in the past, and there was no system in place to report it.
Chikungunya and dengue cause fever and severe joint pain, muscle pain, headache, nausea, fatigue and rash. In case of chikungunya, the joint pain is often very debilitating, but usually lasts for a few days or may be prolonged to weeks.
While dengue can be at times fatal, chikungunya is not. However, for patients with old-age complications or diabetes, chikungunya may lead to fatalities, though no fatalities have been reported yet, said Sanya.
"We are mindful about it and taking measures to address the problem,” he said.
Dr Saif Ullah Munshi, virology professor at the BSMMU, said he was very concerned about the rapid rise of chikungunya cases.
As dengue has been infecting people since 1999 in Bangladesh, many have developed immunity to dengue, but chikungunya is relatively new in the country.
"I fear chikungunya will be widespread," he said, and stressed the need for destroying the breeding grounds of the mosquito that grows in clean water, mostly during monsoon.
The health ministry is coordinating the efforts to prevent further spread of Aedes mosquitoes, Prof Sanya said, adding that they were engaging community people in the efforts.
The DGHS in association with the IEDCR and the two Dhaka city corporations initiated an awareness programme.
As part of it, students of all medical and dental colleges, institutes of health technology and postgraduate medical institutes will hold a campaign from 9:00am to 2:00pm tomorrow in all the 92 wards of the capital, said the DGHS director.
"They would identify the breeding sources of Aedes mosquitoes, destroy those and distribute leaflets among people,” she said.
The city corporation teams will use fog machines and hand-spray machines to kill mosquitoes.