Work by Australian researchers has prompted the World Health Organisation to update its recommendations for malaria-preventing mosquito nets.

Dr Timothy Barker from the University of Adelaide led a team which proved the effectiveness of a new combination of insecticides used in such nets.

Sleeping under a mosquito net is one of the best ways to protect against mosquito bites that spread malaria.

Those treated with pyrethroid insecticides have been distributed in malaria-prone regions globally since 2005 but some mosquitoes have developed a resistance.

"The number of malaria cases actually increased in 2020, whereas there was a continued and steady decrease in the number of malaria cases observed from 2000 to 2019," Dr Barker said.

"Given this, the WHO was interested in a new type of bed net that had been recently investigated in some clinical trials that might combat this issue."

Dr Barker said before any new recommendations on nets could be made, results from individual trials needed to be systematically reviewed and WHO had commissioned his experienced University of Adelaide team to carry out that work.

The researchers analysed the results of controlled trials conducted in the Republic of Benin, Burkina Faso and Tanzania, where mosquitoes were resistant to the standard insecticide.

They found combining pyrethroid insecticide with the chemical chlorfenapyr boosted its lethal effectiveness against mosquitoes, while combining pyrethroid with the chemical pyriproxyfen also helped, though was less effective.

Pyrethroid insecticides aim to kill mosquitoes, chlorfenapyr works in conjunction to weaken mosquitoes, while pyriproxifen is a growth inhibitor.

The chemicals are used in combination to boost the "killing ability" of the nets, Dr Barker told AAP, with no additional harm to people sleeping under them.

Following his team's work the WHO has since updated its malaria guidelines to include nets treated with pyrethroid-chlorfenapyr, as well as with the less-effective pyrethroid-pyriproxyfen combination.

In 2021, nearly half the globe's population was at risk of malaria. There were an estimated 247 million cases and 619,000 deaths worldwide.

"To directly contribute to a recommendation that will prevent people developing malaria, and subsequently reducing the number of people that may unfortunately die due to this terrible disease, is something that I am extremely proud of," Dr Barker said.