Australian scientists work to put bite on mosquito-bourne Zika virus

From genetically engineered mosquitoes to adapting bush medicine, Australian researchers are working on multiple fronts to prevent the arrival and spread of Zika virus in this country.

Zika is a mosquito-bourne virus similar to dengue fever, and is of particular concern because it causes extreme birth defects in babies whose mothers contract the virus. There have been more than 4000 cases of serious birth defects in countries with Zika since 2015.

Since concerns were first raised about the virus in 2015 in Australia, there has been dozens of cases of Zika here, but all of those were contracted overseas by people who then returned here.

Maria Lys was born with microcephaly due to her mother contracting Zika virus in Brazil. Photo: AP

Maria Lys was born with microcephaly due to her mother contracting Zika virus in Brazil. Photo: AP

Health authorities are still on alert for any cases contracted in Australia, with the main mosquito species which carries the disease - Aedes aegypti - common in north Queensland.

The frontline of the battle against the disease is prevention, with CSIRO researchers working on ways to ensure the mosquitoes themselves could be made to reject the disease.

Dr Prasad Paradkar, a senior research scientist with the CSIRO, has been leading a team working with University of California San Diego to genetically engineer Zika-resistant mosquitoes.

Dr Paradkar said currently Zika was being fought with insecticide against the mosquitoes, but there needed to be a more complete solution.

CSIRO senior research scientist Dr Prasad Paradkar working on Zika resistant mosquitoes. Photo: CSIRO

CSIRO senior research scientist Dr Prasad Paradkar working on Zika resistant mosquitoes. Photo: CSIRO

“We used gene-editing techniques to create a Zika-resistant mosquito, which were created in San Diego and then sent over here for use to test in our high-containment lab,” he said.

“We found it’s actually very effective at blocking the transmission of the virus.”

Ultimately the idea would be to release these mosquitoes into the wild, where they would pass on their genetic code to the general population of mosquitoes, forming a natural barrier in the main way the disease is spread.

But Dr Paradkar said there was still some way to go before that could happen.

A female Aedes aegypti mosquito in the process of acquiring a blood meal from a human host.  Photo: AP

A female Aedes aegypti mosquito in the process of acquiring a blood meal from a human host. Photo: AP

“The idea would be that these mosquitoes would replace the wild population of mosquitoes,” he said.

“There are ethical issues that come with that, and a key step would be public discussion, and obviously regulatory bodies would be involved, to answer the question of whether we should use this technology in the wild or not.”

As Dr Paradkar and his team work on getting their technique vetted, a group of Queensland researchers are using bush medicine to develop a drug which could potentially cure people who contract the disease.

QUT's Dr Trudi Collet and the QUT Indigenous Medicine Group have found a plant extract that has a 100 per cent clearance rate for Zika virus, as well as all four strains of dengue fever.

Dr Collet said the finding was “huge”.

“We have a natural extract which does have any of the side-effects of existing medicines but which kills 100 per cent of the virus,” she said.

“We’ve identified the compound responsible, and are in the process of synthesising it in the lab.”

Dr Collet said they hope to have clinical trials under way by the end of the year, with an approved drug on the market within two to three years.

QUT's Dr Trudi Collet and the Indigenous Medicine Group have found a plant extract that has a 100 per cent clearance rate for Zika virus, as well as all four strains of dengue fever. Photo: Supplied

QUT's Dr Trudi Collet and the Indigenous Medicine Group have found a plant extract that has a 100 per cent clearance rate for Zika virus, as well as all four strains of dengue fever. Photo: Supplied

In addition to Zika and dengue, the drug also reportedly has a 100 per cent clearance rate for West Nile virus as well.

“Our goal is to get this into human trials with the aim of having a therapy which can not only treat people who have been infected with one of these viruses, but also could be used as a preventative medicine,” Dr Collet said.

“We’re extremely hopeful, given the data we have, that this will become mainstream medicine, where if you contract one or more of these diseases you just take this and you’re right.”

Dr Collet outlined her work with the plant extract in a presentation at the TEDx conference in Brisbane late last year.

Dr Paradkar and the CSIRO’s work with mosquitoes has been published this week in the journal PNAS.

This story Australian scientists work to put bite on mosquito-bourne Zika virus first appeared on Brisbane Times.