New type of bed net can paralyze mosquitoes

Bed nets have been instrumental in the tremendous progress the world has made in recent decades against malaria, with millions of lives saved. But progress has stalled over the past few years, partly because disease-carrying mosquitoes are increasingly resistant to insecticides used in existing net fabrics.

In 2020, 627,000 people died of malaria, mostly children, in sub-Saharan Africa.

Anopheles mosquito is trapped in a net placed in a rice field during a trial against malaria on the island of Zanzibar, Tanzania, October 30, 2019.

Now, researchers at the London School of Hygiene and Tropical Medicine, UK (LSHTM), the UK's National Institutes of Medical Research, the Kilimanjaro Christian College of Medicine in Tanzania, and the University of Ottawa in Canada have shown found that a new pesticide - for the first time in 40 years - was both safe and effective in a randomized real-world trial.

This raises hopes for a new weapon in the fight against malaria.

The curtains were treated with chlorfenapyr and pyrethroid, commonly used chemicals, which, when compared with existing curtains, reduced malaria incidence by 43% in the first year and 37% in the second year. two of the test.

The study involved more than 39,000 households and followed more than 4,500 children aged 6 months to 14 years. The nets, developed by BASF in Germany and LSHTM, are slightly more expensive than current nets, at around $3 each, but the researchers say savings in preventing fever cases cold has exceeded the initial increase in expenditure.

Chlorfenapyr works differently from pyrethroids, effectively helping mosquitoes to land by causing cramps in their wings and making them unable to fly, and therefore unable to bite people, infecting them with disease. The chemical was first proposed for use against malaria 20 years ago and has been used for pest control since the 1990s.

The World Health Organization (WHO) has approved the use of the new nets, but the trial, funded by the UK government and the Wellcome Trust, could lead to broader recommendations on their use. this screen.

"This is the first evidence in real-world conditions," Dr Jacklin Mosha, lead author of the study from the National Institute of Medical Research, Tanzania, told Reuters.

Along with the development of a malaria vaccine, approved by the World Health Organization last year, the team says the network could be another tool in the malaria toolbox.

However, they warn that it is important provided that mosquitoes do not rapidly develop resistance to chlorfenapyr, if widely used.