Photo story: Innovations for dengue control in Cambodia
1 July 2016
In March 2016 Malaria Consortium Advocacy Manager Alex Hulme visited Cambodia to collect a case study of our "integrated vector management for dengue control in Cambodia" project. Whilst there, he spoke with community health volunteers, members of the community affected by dengue and representatives from the National Dengue Control Programme. He also took some photos of the project in action: here is the resulting photo story that explains the project further.
This project has been funded by UK aid from the UK government and Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH. The views expressed here do not necessarily reflect the official policies of the donor.
Dengue is an endemic disease in Cambodia, with almost 200,000 cases being reported between 1980 and 2008, a figure which is continuing to rise per year.
This increase is reinforced through observations on the ground by the Provincial Health District Dengue Supervisor in Kampong Cham Province in Cambodia, Dr Hayra. “For Cambodia, dengue is an epidemic disease. In Kampong Cham Province the number of dengue cases per year have generally been increasing.” Dr Hayra goes onto say, “Each year many children have this disease; there is a big burden on our hospitals. It especially affects the family’s living standards too.”
For large water storage containers, the use of guppy fish (Poecelia reticulata) to reduce dengue vector populations has shown promise. In Cambodia and Laos, it has been demonstrated that the use of guppy fish is a low-cost, sustainable and effective approach to reduce dengue vector populations.
Photo Credit: Vanney Keo
However, for smaller containers (less than 50 litres) where guppy fish cannot effectively live and breed, Malaria Consortium is also trialling a long lasting slow release larvicide based on the insect growth regulator pyriproxyfen.
The product, provided by Sumitomo Chemical Company, is known as SumiLarv®* 2MR and contains 2% pyriproxyfen. Pyriproxyfen acts at immensely low concentrations to prevent the adult emergence of the mosquito thereby reducing the number of vectors which could carry dengue. This particular product is different to many of its predecessors as it remains effective for a long time (approximately six months) before needing to be replaced and so can work for the whole duration of the rainy period.
*SumiLarv is a registered trademark of Sumitomo Chemical Company Ltd.
Working in Kampong Cham Province, Malaria Consortium has been using both of these vector control methods alongside behaviour change methods among populations who are most at risk of contracting dengue. This strategy is called Communication for Behaviour Impact (COMBI), which outlines a social mobilisation and communication approach that connects knowledge and behaviour, addresses the value of engaging in healthy behaviours, and recognises the gradual stages of behaviour change.
Central to this approach is effective training of community health volunteers so they are able to go back to their communities and change behaviours of their peers. As Sen Sokky from Chor Chork village highlights, “When I got training from dengue prevention experts, they gave me leaflets and explained all parts of the leaflet and how to explain it properly to my villagers so they can get the full information on dengue and how to prevent it.”
Sen also explains her role in the project from behaviour change to distributing and maintaining the guppy fish. “I went to each house in my village twice a month to give a basic knowledge of dengue and how to prevent it and checked the guppy fish in water containers. If the guppy fish were not present, I would replace it with new ones.” By pursuing behaviour change initiatives, Malaria Consortium has tried to ensure that preventive measures are accepted and practiced by the local communities.
The effectiveness of these different interventions are being monitored throughout the project in the form of quarterly entomology surveys, yearly knowledge, attitudes and practice surveys, and monthly meetings of health workers. As Dr Sam Bunleng, an entomologist from the NDCP involved in the project highlights, “We want to know more about the mosquito that transmits dengue and whether it is increasing or decreasing. Because when you put the guppy fish or biological agent it is important to understand how effective they are in controlling the mosquito.”
In addition to the entomology work done in the Kampong Cham laboratories, the mosquitoes are also sent to the US Naval Medical Research Unit 2 (NAMRU-2) where they do polymerase chain reaction (PCR) tests in order to get an understanding of the proportion of mosquitoes which are carrying the dengue virus.
The evidence produced from this project of what works and is the most effective method of controlling the vectors and changing behaviours will drive the policies of the NCDP moving forward. It will also be crucial to see the scale up of the interventions that are proven to work most effectively into more districts and provinces across Cambodia.
“If we can show these interventions work, then we can use these results as a proof of concept that they do reduce number of mosquitoes,” Malaria Consortium’s project lead, John Hustedt, suggests. “This will allow us to expand the project to a larger area and look not just at entomology but disease surveillance. This can help us determine the effect of the number of mosquitoes on dengue cases and will provide a compelling case to use a community based intervention that is sustainable.”
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Country: Cambodia
Keywords: Maternal, neonatal and child health | Community delivery | Vector control