Sesame oil was used in a ground-breaking trial in Burkina Faso which genetically modified a fungus in order to kill malaria-carrying mosquitoes, BBC News reported on 31 May.

Trials that were carried out showed mosquito populations collapsed by 99% within 45 days.

Researchers in the study by the University of Maryland and the Research Institute of Health and Sciences (IRSS) in Burkina Faso selected the metarhizium pingshaense fungus, which naturally infects the Anopheles malaria-spreading mosquito.

They then genetically modified the fungus to produce a toxin found in the venom of a species of funnel-web spider found in Australia.

The genetic instructions for making the toxin were added to the fungus’ own genetic code so it would start making the toxin once it was inside a mosquito.

The fungus was then tested in a 6,500 square foot fake village complete with plants, huts, water sources and food for mosquitoes, with a double layer of mosquito netting to prevent anything from escaping, BBC said.

The fungal spores were mixed with sesame oil and wiped onto black cotton sheets. The mosquitoes had to land on the sheets to be exposed to the fungus.

Researchers started the experiments with 1,500 mosquitoes and their numbers soared when left alone. But when the spider toxin fungus was used, there were just 13 mosquitoes left after 45 days.

The fungus was specific to the mosquitoes and did not affect other insects such as bees.

Diabate Abdoulaye, head of the IRSS’ medical entomology laboratory, said the findings, published in Science journal, offered hope of a new way to fight malaria.

The World Health Organization (WHO) said last year that there had been no significant progress in reducing global malaria between 2015 and 2017 due to insecticide resistance problems.

WHO said more than 400,000 people died of malaria each year, and there were around 219M cases in 87 countries in 2017.