Malaysian Public Health Entomologist in vector control Dr. Moh-Seng Chang talked about how little vector control has changed since the 70s. In this article, he shares what he feels could be done better when it comes to fighting outbreaks of dengue fever and other diseases like Zika and chikungunya spread by the Aedes aegypti mosquito.

“Local authorities should be handed the responsibility for house inspections, education, law enforcement, use of insecticides, and community mobilization…”

Doing it better 

Dr. Chang has some clear views on how things could work better. “Local authorities should be handed the responsibility for house inspections, education, law enforcement, use of insecticides, and community mobilization,” he tells us. Central government agencies would provide technical help and operational research support.

This would work better because:

• Resource allocation is more effective at a local level where the manpower and equipment actually is.
• Vector control can easily be incorporated into basic sanitation, rubbish collection, and other environmental programs already run by the local authorities, making dengue prevention and control more sustainable.
• Many of the sites where the mosquitoes are harbored and active during the peak biting hours of the day – such as public parks – are already owned and managed by the local authority.
• Community mobilization and interagency involvement are more effective with community leaders and villagers more closely associated with the local authority.

Dr. Chang also stresses the need for the involvement of the private sector. He gives an example of a recycling opportunity. A tire recycling plant would significantly reduce the number of abandoned automobile tires and the stagnant water breeding grounds they hold. “Private sector involvement is needed to provide the investment required for buying the machines for breaking down the tires and for creating the new materials,” he says.

Proper evaluation vital to success  

At a time when many vector control programs run in isolation without involving other relevant organizations, Dr. Chang agrees that integrated vector control management is the way forward.

He highlights the importance of good planning and management. “Integrated vector management needs good planning that spells out the details of who, how, when, and where. The communities and other sectors involved will need to clearly understand their roles, which must be relevant to them to ensure they maintain their commitment. Coordination and better program management are the keys.”

Vector control tools, and options need to be scientifically sound. Transmission sites and seasonality, community perception and acceptance, and insecticide susceptibility level, among many other things, need to be understood. Without proper evaluation upfront and monitoring along the way, vector control programs risk failure.

Image courtesy of Dr. Chang

Dr. Chang believes too many community vector control tools developed are abandoned after a short period of time simply because they don’t take the desires and behaviors of participants into account. “If they are going to accept and contribute to a vector control operation, communities and participating agencies need to be interested and willing to take ownership,” he comments. “For this they need to both understand and benefit from it.”

A way forward  

There are some key steps that Dr. Chang believes we should be taking to prevent dengue outbreaks now to improve the situation:

Improve disease surveillance

Make low cost, rapid test kits more widely available to ensure dengue cases are discovered and reported quickly. Early diagnosis and treatment prevents death, while early notification enables emergency vector control to be initiated – meaning outbreaks are more likely to be contained.

Enhance environmental management and sanitation 

Encourage recycling schemes for plastic containers along with environmental maintenance and cleaning programs. Ensure contractors on green projects understand the implications for dengue and minimize the risk.

Plan for the vaccine

Understand how it should be used and how it can be delivered to the wider community. But even with the vaccine, prevention and vector control still has a role to play. The two should work together in parallel.

Evaluate new techniques

New innovations are emerging. We need to understand the role they will play and how they can be incorporated with on-going initiatives.

• Genetically modified mosquitoes
• Mosquitoes infected with Wolbachia that blocks dengue transmission
• Attractants that lure the female mosquito to lay eggs, then kills them
• Insecticide-treated screens and materials that form toxic resting sites

Furthermore, Dr. Chang is working on gaining a better understanding of the relationship between urbanization and dengue; on understanding the impact of development and changes in vector ecology. He’s also on the lookout for other potential Aedes mosquitoes that could potentially transmit dengue as ecology changes.

“Today, dengue prevention and control is solely relying on vector control and the programs have a long way to go. In any vector control program, monitoring and evaluation should be an integrated part of vector control elements. Vector control tools used should be integrated, evidence-based, use community approaches, and must be preemptive – anticipating outbreaks. Even when the dengue vaccine becomes operationally available in the near future, vector control programs will still have a role to play,” concludes Dr. Chang.

Furthermore, Dr. Chang is working on gaining a better understanding of the relationship between urbanization and dengue; on understanding the impact of development and changes in vector ecology. He’s also on the lookout for other potential Aedes mosquitoes that could potentially transmit dengue as ecology changes.

“Dengue prevention and control is solely relying on vector control and the programs have a long way to go. In any vector control program, monitoring and evaluation should be an integrated part of vector control elements. Vector control tools used should be integrated, evidence-based, use community approaches, and must be preemptive – anticipating outbreaks. Even when the dengue vaccine becomes operationally available in the near future, vector control programs will still have a role to play,” concludes Dr. Chang.

—

Click below to join Dengue Track and put your data to work.

https://breakdengue.wpengine.com/dengue-track/?utm_source=wordpress&utm_medium=socialpost&utm_campaign=denguetrack