Exciting potential to eliminate dengue with wolbachia-infected mosquitoes

The World Mosquito Program from Monash University together with Gadjah Mada University and Tahija Foundation, recently announced the exciting potential of Wolbachia-infected mosquitoes to control dengue. The results of a randomised controlled trial published in the New England Journal of Medicine show that the incidence of dengue was reduced by 77% in areas of Yogyakarta, Indonesia where mosquitoes with Wolbachia were released and that dengue cases requiring hospitalisation were reduced by 86% in the Wolbachia-treated areas. The efficacy was equivalent for all four serotypes of dengue, which creates possibilities to control the rise of dengue cases across tropical countries, including Thailand.

 

The trial, “Applying Wolbachia to Eliminate Dengue (AWED)”, aimed to test whether the introduction of Wolbachia (wMel) into the local Aedes aegypti mosquito population through the release of Wolbachia-infected mosquitoes would reduce the incidence of virologically-confirmed dengue among 3-to-45 year old living in Yogyakarta, Indonesia. More than three years after completion of mosquito releases, Wolbachia remains at a very high level in the local mosquito population. Since the trial, the Wolbachia method has been implemented across the entire city of Yogyakarta and releases have commenced into neighbouring districts, to cover a population of 2.5 million people.

 

 

The Prevalence of Dengue Fever in Thailand

 

Dengue is the most rapidly spreading mosquito-borne disease in the world, with more than 50 million cases globally every year. According to a recent report from Department of Disease Control, Ministry of Public Health, there is no exception for Thailand where dengue is highly endemic with an average of 60,000+ dengue cases found annually between 2016-2020. In 2021, 25,708 cases were reported across the country to date including 15 deaths, and the numbers of cases of infection is expected to increase.

 

Siripen Kalayanarooj, M.D., clinical professor at Queen Sirikit National Institute of Child Health and World Health Organization consultant on dengue fever shared, "The results from Wolbachia-infected mosquitoes are amazing. This means a very promising future for successful dengue prevention and control."

 

 

Wolbachia – the hope to reduce spiking Dengue cases

 

The AWED trial results are consistent with previous trials of the Wolbachia method, which show long-term reduction in dengue incidence once Wolbachia is sustained within the local mosquito population. Studies also show the Wolbachia method to be effective in also preventing the transmission of Zika, chikungunya, yellow fever and other vector-borne diseases.

 

Co-Principal Investigator, Prof. Cameron Simmons from Monash University believes that these results showcase the significant impact the Wolbachia method can have in reducing dengue in urban populations. “This result demonstrates what an exciting breakthrough Wolbachia can be - a safe, durable and efficacious new product class for dengue control is just what the global community needs,” he said.

 

World Mosquito Program Director, Prof. Scott O’Neill said, “This is the result we’ve been waiting for - evidence that our Wolbachia method is safe, sustainable and dramatically reduces incidence of dengue. It gives us great confidence in the positive impact this method will have worldwide when provided to communities at risk of these mosquito-transmitted diseases.”

Prof. Cameron Simmons            

Prof. Scott O’Neill             

 

Prof. Adi Utarini

 

Co-Principal Investigator of the trial, Prof. Adi Utarini from the University of Gadjah Mada, believes the trial success allows for expansion of the project across the entire city of Yogyakarta and into neighbouring urban areas. She added “We think there is a possible future where residents of urban cities across South East Asia can live free of dengue.”

 

The future of using Wolbachia-infected mosquitoes to control Dengue

 

The potential for this Wolbachia method to be deployed across communities worldwide has been acknowledged by the World Health Organisation, whose Vector Control Advisory Group declared “Wolbachia demonstrates public health value against dengue” recently.

 

These results have significant implications for 40% of the world’s population at risk of dengue. The World Mosquito Program aims to work in partnership with national and local governments, corporate citizenship programs, charitable organizations and non-governmental organizations to expand Wolbachia protection worldwide. To date, the World Mosquito Program has supported releases in 11 countries in Asia, Australia, Latin America and the Pacific with an estimated 6.8 million people now benefiting from Wolbachia coverage.

 

In conjunction with the publication of the trial results in the New England Journal of Medicine, the World Mosquito Program released a video and animated short video, describing the trial, its results and the implications for combatting dengue in the future.