A new approach to combating the spread of dengue fever has proven very effective in Indonesia. By infecting the insects with a certain bacterium, the researchers were indeed able to bring down the number of infections and hospital admissions.
Dengue fever is a viral syndrome transmitted by mosquitoes Aedes aegypti and Aedes albopictus (also called tiger mosquito), and caused by one of the four dengue virus serotypes (DEN1 to DEN4). Considered one of the top ten threats to global health in 2019 by the World Health Organization, this disease affects 50 to 100 million people worldwide each year. The most common symptoms are fever and joint pain, but its complications can be severe.
To tackle dengue fever, many countries have focused their efforts on insecticides or environmental management methods, with the aim of controlling vector mosquito populations. However, as pointed out by a team of researchers in the New England Journal of Medicine , these approaches were not effective.
In recent work, Indonesian public health researcher and dengue specialist Adi Utarini has recently focused on Wolbachia pipientis. It is an intracellular bacterium that infects many species of insects, but not the A. aegypti mosquito. However, this bacterium is known to inhibit viral replication, which makes it more difficult for infected insects to spread the disease.
With her team, the researcher has therefore developed a program aimed at voluntarily infecting several million mosquitoes before releasing them in more than half of the city of Yogyakarta, in Indonesia, where dengue is endemic. The goal:that the bacterium Wolbachia pipientis, able to manipulate its host to ensure that it is inherited by the next generation, can quickly spread through mosquito populations.
And the results are spectacular! This work, carried out over a period of nine months in 2017, has in fact made it possible to reduce registered dengue fever cases by 77%, while hospitalization cases have been reduced by 86%.
Following the success of the trial, mosquitoes have since been released throughout the city, with more soon to be released in surrounding areas.
“This is a big success for the people of Yogyakarta. Indonesia has more than 7 million cases of dengue each year. The success of the trial allows us to expand our work to the whole city of Yogyakarta and surrounding urban areas. We believe there is a possible future where people in Indonesian cities can live dengue-free” , Adi Utarini said in a statement.
Cameron Simmons, co-author of the study, points out that the use of mosquitoes infected with Wolbachia could also be applied to treat other diseases, such as Zika, yellow fever and chikungunya.
