Groundbreaking trial sees dengue fever cases fall by 77pc in Indonesia
Dengue fever cases have been slashed by 77 per cent in a groundbreaking trial study in Indonesia, that researchers hope can be expanded worldwide to dramatically reduce the impact of the potentially fatal virus.
The three-year experiment in Yogyakarta, on the island of Java, tested whether infecting Aedes aegypti mosquitoes – the normal carriers of dengue – with bacteria called Wolbachia would reduce incidences of dengue among three to 45-year-olds.
The results, published in the New England Journal of Medicine, show a 77 per cent fall in cases, and an 86 per cent reduction in hospitalisations in Wolbachia-treated areas.
The World Mosquito Programme team that conducted the trial said it could not only offer relief to Indonesia where, like much of Southeast Asia, it is highly endemic, but that it could help to curb the spread globally, reducing the burden on healthcare systems and economies.
Dengue is the most rapidly spreading mosquito-borne disease in the world, with more than 50 million cases occurring globally every year. An estimated 8 million of these are in Indonesia.
The disease causes fever, joint and muscle aches, nausea, and in some cases can be fatal.
Wolbachia is not harmful to mosquitoes. The method works by competing with the dengue virus in its body and making it harder for the virus to replicate and cause an infection when the insect bites.
Studies also show the Wolbachia method to be effective in also preventing the transmission of Zika, chikungunya, yellow fever and other vector-borne diseases.
“This is the result we’ve been waiting for,” said Prof Scott O’Neill, the World Mosquito Programme director.
“We have evidence our Wollbachia 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.”
The experiment began more than three years ago, when Wolbachia was released into the local mosquito population in certain parts of the city. Efficacy was equivalent for all four serotypes of dengue.
Following its success, the Wolbachia method was introduced across the entire city and releases have now been expanded into neighbouring districts, to cover a population of 2.5 million people.
“We think there is a possible future where residents of Indonesian cities can live free of dengue,” said Co-Principal Investigator of the trial, Prof. Adi Utarini from the University of Gadjah Mada.
Economic studies have estimated that there were on average 14,000 dengue cases including 2000 hospitalisations in Yogyakarta each year prior to the new method.
“The results are compelling,” said Prof Nicholas Jewell, the trial’s independent statistician and Professor of Biostatistics and Epidemiology at the London School of Hygiene & Tropical Medicine.
“Doubly exciting is that the trial design used here provides a template that other candidate health interventions can follow.“