While new weapons of attack against the deadly little mosquito causing dengue fever has brought promising results, health authorities vowed they would intensify their efforts in the wake of fears of another dengue outbreak, with the onset of the monsoons. Health Minister, Dr Rajitha Senartne has warned that the number of cases currently at low prevalence in the Western, Northern and Central Provinces could spike unless breeding sites are immediately eradicated. Health sources also urged anyone with fever for over 3 days to be seen by a physician at the closest hospital.
Epidemiology Unit sources said, the number of suspected dengue cases islandwide tumbled from nearly 41,000 in July to half the number ( 21,608) in August and by more than fifty percent in September at 8,386 cases. “This is the first time the prevalence rate has dropped to such a low figure”, Dengue Control Unit sources said.
Turnaround
This remarkable turnaround of a disease that killed over 230 persons and sent thousands to hospital with suspected symptoms has been attributed to the concerted ongoing efforts of all stakeholders – along with the innovative methods currently being tried out to eliminate the large mosquito population in the country. The latter includes house to house inspections, fogging, spraying and Ovi traps.
Responding to a query by the Sunday Observer, the Chief Medical Officer, Colombo Municipal Council ( CMC) Dr Ruwan Wijemuni who oversees one of the most congested areas, with the highest prevalence rate in the Western Province says, “In August we had 473 cases which fell to 155 last month. This month so far we have 49 cases”. However, with the onset of the monsoon by November he says, there could be another dengue outbreak if mosquito breeding sites are not eradicated country wide. He said, the next mosquito eradication program in the Colombo Municipal area would be held ahead of the monsoons. “On November 21 and 22 our PHIs , members of the Tri Forces and environment health staffers deploy over 600 people to first inspect houses in high risk areas of the city previously marked out. They include, housing schemes at Modera, Grandpass, Hunupitiya, Dematagoda , Narahenpita, Pamankade and Wellawatte, where overcrowding has resulted in a high increase in the mosquito population.
Householders will be warned if their premises are found to contain uncleared rubbish, plastic containers, lunch sheets, tyres, uncleaned gutters and water receptacles which have not been cleaned. They will be given two weeks to clean up their premises, or fined. This year alone we have filed cases against 621 offenders and collected Rs 1.8 million by way of fines from offenders”, he said.
He said, within the city, methods used would differ. “We are now sending our PHIs early morning, from 5.30 a.m to 7 a.m to fog high risk areas such as, condominiums, public and private buildings, offices, schools and religious places, as well as construction sites. We are also spraying the walls of houses of the low income, with Adulticide to kill the mosquitoes.
In addition, we are trying out laying Ovi traps, which trap the female mosquito and prevents it from getting into the surroundings, with a wire mesh. However, this has not been very successful”, he admits.
The current dengue virus sero type 2 ( DENV-2) has been identified as the circulating strain in the recent outbreak.
“Dengue Fever is caused mainly from small containers. To a large extent the public is to blame for its spread”, Dengue Control Unit sources charged, adding that the response from the public was “ not up to expectations” .
Not all members
“Even though we follow the rules, the garbage on our road is not collected regularly. On rainy days the bags get soggy and garbage spills on the road attracting flies, mosquitoes and dogs,” complained a resident of Dematagoda.
So, is there a solution on the horizon?
A wise old owl to whom we posed this question said, “Collecting garbage is the CMC’s responsibility. Ours is to eliminate breeding sites in our own premises. If not, we too can become victims of dengue”, says this learned professor.
Meanwhile, most Colombo hospitals contacted by the Sunday Observer said, the long queues outside their OPDs had reduced considerably; “We now have a handful of persons – between 20-25 of suspected cases of dengue coming for examination. In the hospital there are only about 25 in patients”, Colombo South Teaching Hospital, Director, Dr Asela Gunewardene said. He said, the Hospital was also continuing with its own eradication programs, and all desks for screening were in operation. Asked if they were ready to meet any emergency should there be an outbreak, he said,” We are fully equipped and have all the facilities.
New vaccine
Trials for developing a vaccine against dengue are also underway. “It will take some years to be released as it is being evaluated. It will be effective for all four types of dengue stero types in Sri Lanka” an unnamed source said.