Nearly 2 million dengue inspections this year: Dr Vivian Balakrishnan

Channel NewsAsia 4 Aug 14;

SINGAPORE: The National Environment Agency has conducted nearly 2 million dengue inspections this year, and deployed more than 1,000 Gravitraps in dengue clusters for mosquito-control purposes, Minister for the Environment and Water Resources Dr Vivian Balakrishnan said in Parliament on Monday (Aug 4).

There have been more than 12,000 reported dengue cases so far this year, Dr Balakrishnan said. This dengue epidemic, which has been ongoing since 2013, was driven by three factors:

There was a switch in the predominant dengue serotype to DENV-1 last year. This strain of DENV-1 virus spreads more rapidly than other strains in Singapore and now accounts for about 90 per cent of the current infections.

Singapore's general population lacks immunity to dengue due to cumulatively low incidence over the last two decades.

The mosquito Aedes aegypti is still endemic in Singapore despite efforts over the years.

Dr Balakrishnan said the National Environment Agency (NEA) has increased the frequency of inspections and taken enforcement action against errant contractors, whose sites have seen the breeding of mosquitoes. So far this year, 57 Stop Work Orders have been issued and 14 contractors prosecuted in court, he said.

Penalties have also been levied on homeowners, town councils and other landowners when breeding is found within their premises, he added. This year, the fines levied ranged from S$200 for home owners to S$39,000 for construction contractors.

BIOLOGICAL INTERVENTION

When it comes to developing new tools to tackle dengue, Dr Balakrishnan said NEA's Environmental Health Institute (EHI) is working with local researchers to utilise the Wolbachia bacteria.

"We are currently studying the feasibility of using Wolbachia-carrying male Aedes aegypti mosquitoes to suppress the mosquito population in Singapore. A Dengue Expert Advisory Panel consisting of international and local experts has been appointed to provide scientific advice on the safety and effectiveness of this technique in our context. As this is a novel biological intervention, we will not embark on any field trials unless it is clear that safety is totally assured."

Responding to questions from Members of Parliament on whether the Government will approve the Sanofi vaccine, Dr Balakrishnan said more needs to be done to ensure its efficacy. "It showed some promise, but to be honest with you, my frank opinion is that it is not good enough. Why do I say that? It showed reasonable effectiveness, about 75 per cent for Type 3 and Type 4 serotypes of dengue," he said.

"Against Type 1, which is the current problem we are having, it is only about 50 per cent effective. Against Type 2, which is the predominant dengue serotype which circulates in Singapore, it was only about 35 per cent effective. Those rates of efficacy are not, in my opinion, good enough."

Dr Balakrishnan said that Singaporeans must continue to stay vigilant and keep their homes free of breeding habitats. He said since January, more than 4,000 breeding sites have been found in residential premises.

- CNA/ac


Dengue vaccine ineffective against main S’pore strains
Paul Lim Today Online 5 Aug 14;

SINGAPORE — A highly-anticipated vaccine being developed for dengue that is in the advanced stages of clinical trials is not effective against the strain that is dominant in Singapore, said Environment and Water Resources Minister Vivian Balakrishnan yesterday.

Referring to the drug being developed by French pharmaceutical giant Sanofi Pasteur, the minister said that while it showed some promise for Type 3 and 4 dengue, it is only about 50 per cent effective against Type 1 — the dominant strain here — and 35 per cent effective against the next most common strain here, Type 2.

“Those rates of efficacy are not, in my opinion, good enough,” said Dr Balakrishnan.

However, the authorities are studying the feasibility of using Wolbachia-carrying male Aedes aegypti mosquitoes to suppress the dengue virus-carrying mosquito population, he said.

An advisory panel consisting of international and local experts has been appointed to provide scientific advice on the safety and effectiveness of this technique in the Singapore context, said Dr Balakrishan, who stressed that “unless it is clear that safety is totally assured”, there will be no field trials.

More than 12,000 dengue cases have been reported here this year, leading to questions about whether the Sanofi drug will be made available, despite mixed results in the latest study conducted among more than 10,000 children aged between two and 14 in Indonesia, Malaysia, Thailand, the Philippines and Vietnam.

Noting that efforts have been stepped up to curb the number of breeding sites — more than 1.9 million inspections have been conducted and more than 1,000 Gravitraps deployed this year — Dr Balakrishnan stressed that the community still had to play its part to combat dengue.

“We can have 850 National Environment Agency officers and 1.9 million inspections, but it is not possible for officers to be everywhere all the time. This is where I really require the assistance of home owners, contractors, town council officers and even Members of Parliament. It does make a difference,” he added.

Nevertheless, Dr Balakrishnan said it was worth considering some of the calls that have been made to enhance penalties.

Suggestions mooted in the House yesterday included pegging penalties to the size and scale of the mosquito breeding ground, or publishing the list of pest control companies looking after sites that were found to have mosquitoes breeding.

Minister: Dengue vaccine not good enough
Dr Balakrishnan, a trained medical doctor, explained that the vaccine was not effective enough against the two most common types of dengue virus here, type 1 and type 2.
Grace Chua The Straits Times AsiaOne 5 Aug 14;

SINGAPORE - A new dengue vaccine, to be marketed by French pharmaceutical firm Sanofi next year, is "not good enough" for Singapore, said Environment and Water Resources Minister Vivian Balakrishnan in Parliament yesterday.

He was responding to queries from Members of Parliament on when the vaccine and other new drugs would hit the shelves here.

Dr Balakrishnan, a trained medical doctor, explained that the vaccine was not effective enough against the two most common types of dengue virus here, type 1 and type 2.

The vaccinated group's risk of developing dengue is reduced by 50 and 35 per cent respectively for type 1 and 2, compared with an unvaccinated group.

"Until further clinical data is available for us to be sure that the benefits outweigh the risks, I don't think the Ministry of Health or Health Sciences Authority will rush into approving the vaccine," he said.

Meanwhile, celgosivir, an anti-viral treatment derived from plant seeds, has not been proven to be more effective than a placebo though it is found to be safe, Dr Balakrishnan added.

Members of Parliament also asked if the fines for mosquito breeding could be scaled based on the risks that the breeding poses to the public. For instance, Chua Chu Kang GRC MP Zaqy Mohamad wanted heftier fines for construction firms found to have mosquitoes breeding on worksites.

Nee Soon GRC MP Lee Bee Wah suggested that pest control firms that fail to control mosquito breeding at worksites be blacklisted.

Dr Balakrishnan said the ministry will study the suggestions on raising penalties but warned that pinning a specific case of dengue on a specific incidence of mosquito breeding would be hard.

To date, 62 stop-work orders have been issued and 14 contractors prosecuted this year for allowing mosquito breeding on their premises.

The number of weekly dengue cases for the last week was 640, down from a record high of 891 cases at the end of June and start of last month.