Initial releases complete in Colombo, Sri Lanka | World Mosquito Program Skip to main content

Initial releases complete in Colombo, Sri Lanka

Since 2000, dengue cases have been reported from all provinces in Sri Lanka. Over the past decade, there have been 30-50,000 cases annually, not counting 189,000 cases recorded during an epidemic in 2017.

Aedes aegypti is the main vector of dengue in Sri Lanka. As there is no drug or vaccine, mosquito population control measures have been the only method to control the spread of the disease. These include source reduction, biological control and chemical control. 

In 2018, the World Mosquito Program (WMP) partnered with the Ministry of Health (MOH) to implement a pilot project in two high risk dengue areas of urban Colombo, specifically the Colombo Municipal Council-District 1 and Nugegoda. This release covered 19.4 km2 and a population of 214,835 residents. The project was implemented through the National Dengue Control Unit (NDCU) with procurement support from Eduko Lanka.

In a community survey, 98% of respondents in the release areas accepted Wolbachia mosquito releases in their communities.

All over the country now they know about this Wolbachia project after starting the project here. So I think in the near future there won’t be any problem to start in the other parts of the country.
Dr Sasanka Ranasinghe
Ministry of Health, Colombo

“Mozzie boxes” were placed throughout the community weekly to deploy mosquito eggs that develop into adults in the field. 3,258 community volunteers hosted Mozzie Boxes at their residences each week. The releases faced several interruptions due to the COVID-19 pandemic and were eventually completed in April 2021.

A network of 183 mosquito traps were installed in households across the release area to monitor mosquito populations before, during and after release. To align with social distancing protocols during lockdown, trap hosts collected mosquitoes from the traps themselves and left them outside their house for WMP staff to collect. 

The pilot project was closed on 30 June, 2021. The sustainability of Wolbachia in the Aedes aegypti mosquito population will be assessed by NDCU every 6 months for up to 5 years following completion of releases. The impact of the intervention on dengue incidence in the release areas will be assessed for the same period

Plans are underway to expand the use of the WMP Wolbachia method across other areas of Colombo district at high risk of dengue outbreaks.

Want to learn more about the World Mosquito Program and our sustainable and nature-based Wolbachia method?