Dengue transmission impeded by bacterium

Researchers have found that the Aedes aegypti mosquito carrying the dengue virus can be prevented from transmitting the disease by strains of a bacterium commonly found in fruit flies. Their discovery could pave the way to develop effective methods for worldwide dengue control.

Mathematical biologist Dr. Alun Lloyd of the North Carolina State University is a part of the Eliminate Dengue program, which is a research group involving scientists from Australia and the United States.

The program aims to deploy into the wild mosquito population a naturally occurring bacterium called Wolbachia, harmless to humans, to prevent the the Aedes aegypti mosquito from transmitting the dengue virus.

Lloyd explained, “When mosquitoes carrying Wolbachia are introduced into the environment, they mate with wild mosquitoes, and pass Wolbachia to their offspring until all Aedes aegypti mosquitoes have Wolbachia. If mosquitoes don’t become infected with dengue, they cannot transmit the virus to people.”

Female mosquitoes were infected with two different strains of Wolbachia bacteria known as wMel and wMelPop-CLA, and researchers examined the capability of the bacterial strains to spread throughout the mosquito populations under controlled conditions. Results of the experiments revealed that dengue virus transmission was prevented by both strains, and that the entire test population was infected with only a few generations of the wMel strain.

The researchers were able to infer results of their experiments through Lloyd’s mathematical models, which identified the wMel strain as having a greater capability to prevent the spread of the dengue virus.

Lloyd says, “This is a simple, non-chemical, non-harmful way to reduce the threat of dengue to humans. It could have a transformative effect on the health of literally millions of people worldwide.”