24 August 2006

Dengue is a major public health challenge in Singapore, for which mosquito control (particularly source reduction) constitutes the main focus, unfortunately with a heavy reliance on chemicals. In this endeavour, Bacillus thuringiensis var. israelensis (Bti), a safe and target-specific microbial control agent that was first discovered in 1911, could be used as an environmentally friendly alternative to chemicals for mosquito larval control. However, its usage in Singapore has been limited to-date.

Researchers from the Environmental Health Institute, together with collaborators: Origin Exterminators Pte. Ltd. (Singapore) and Valent BioSciences Corporation (USA), studied the applicability of two Bti formulations – VectoBac 12AS (12% aqueous formulation) and VectoBac WDG (granular formulation) – at 5 construction sites in Singapore, via Ultra Low Volume (ULV) spray. Factors assessed included: effective distance coverage and residual efficacy of the misted Bti; backpack- and vehicle-mounted equipment comparison; effective treatment by Pest Control Operators (PCOs); and feasibility of large-scale implementation for enhanced public health outreach.

About the Speaker:

Dr Christina Liew
Medical Entomologist
Senior Research Scientist

Environmental Health Institute (EHI)
National Environment Agency (NEA)

Christina Liew is trained in Medical Entomology, and obtained her BSc (Hons) in Biology from Imperial College (London), and an MSc in Medical Parasitology from the London School of Hygiene & Tropical Medicine, before undertaking her PhD at the National University of Singapore. She has more than 10 years of experience working on the biology and bionomics of the Aedes mosquito. Christina joined the National Environment Agency in August 2002, and is currently a Senior Research Scientist at the Environmental Health Institute. Her main portfolio at EHI is to lead the Vector Research Section and support NEA’s public health objectives with applied research. Key fields of interest include: novel vector control approaches; mosquito traps; microbial control agents (e.g. Bti); vector reference collection for emerging disease preparedness; virus-infected and transgenic mosquitoes.

Last updated on 25 Jun 08

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DATE: 24 August 2006 TIME: 11am to 12pm VENUE: ENV Theatrette, 4th Storey,40 Scotts Road (Environment Building) Admission is free but click button below to register:

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