Genetically modified mozzies fight dengue

CSIRO and the University of California San Diego have engineered what is claimed to be the first breed of genetically modified mosquitoes resistant to spreading all four types of the dengue virus. The research is published in PLOS Pathogens.

CSIRO Senior Research Scientist Dr Prasad Paradkar said the dengue virus was causing an epidemic in tropical and subtropical regions worldwide, with large outbreaks currently occurring in Bangladesh, Pakistan, Sri Lanka and the Philippines.

“There is a pressing global demand for effective strategies to control the mosquitoes that spread the dengue virus, as there are currently no known treatments and the vaccine that is available is only partially effective,” Dr Paradkar said.

“In this study we used recent advances in genetic engineering technologies to successfully genetically modify a mosquito, the Aedes aegypti, with reduced ability to acquire and transmit the dengue virus.

“This is the first engineered approach that targets all four dengue types, which is crucial for effective disease suppression.

“Mosquito-transmitted viruses are expected to climb over the coming years, which is why CSIRO is focused on developing new ways to help solve this global challenge.”

University of California San Diego Associate Professor and study co-author Omar Akbari said this development means that in the foreseeable future there may be viable genetic approaches to controlling dengue virus in the field, which could limit human suffering and mortality.

“This breakthrough work also has the potential to have broader impacts on controlling other mosquito-transmitted viruses,” Assoc Prof Akbari said.

“We are already in the early stages of testing methods to simultaneously neutralise mosquitoes against dengue and a suite of other viruses such as Zika, yellow fever and chikungunya.”

Previous attempts to engineer mosquito populations to make them resistant to the dengue virus have had limited success due to their ability to target only one or two of the four major dengue types.

Infecting more than 390 million people each year, symptoms of dengue fever include severe fever, headaches and muscle aches, with severe forms of the disease leading to haemorrhage, shock and even death.

Global economic losses as a result of dengue are currently estimated to be $40 billion a year.

Image courtesy of CSIRO.