A family in Côte d’Ivoire living inside a mosquito net. Provided by Yonhap News
The World Health Organization (WHO) has recommended the use of next-generation mosquito nets to combat malaria-carrying mosquitoes. Since 2005, more than 2 billion insecticide-treated mosquito nets have been distributed worldwide to prevent malaria. However, this is because mosquitoes have become resistant to existing insecticides, so mosquito nets treated with other insecticide ingredients are needed.
The use of mosquito nets is known to have contributed to reducing the incidence of malaria by about 40% between 2000 and 2015. But in recent years, malaria has risen again as resistance to pyrethroids, the main insecticide used in mosquito nets, has spread. According to the London School of Hygiene and Tropical Medicine (LSHTM), 627,000 people died from malaria in Africa alone in 2020, mostly children.
The new mosquito nets recommended by the WHO are treated with an additional chemical called ‘chlorfenapyr’ to the existing insecticide pyrethroid. Chlorfenapyr is a new insecticide that targets the mitochondria of mosquitoes, inducing muscle spasms and preventing them from moving or flying.
Chlorfenapyr was first introduced in the United States in 2001 for use on non-food crops in greenhouses. Spraying in fields is not permitted as it can be toxic to birds and aquatic animals, but when used indoors it is considered relatively safe as it has little impact on the external environment.
In fact, LSHTM followed up the effectiveness of mosquito nets additionally treated with chlorfenapyr for 2 years on 39,000 households in Tanzania and 54,000 households in Benin. It has been shown to be safe and effective, reducing the incidence of malaria by almost half. The results of the two large-scale studies were published in the international journal ‘The Lancet’ in March last year and January this year, respectively. The WHO is said to have made recommendations based on the findings of the study.
“This WHO recommendation is an important milestone in the fight against malaria and has been reached after nearly 20 years of innovation and research,” said Professor Corinne Ngupo of LSHTM, who led the study in Benin. It is hoped that this large-scale distribution will be of great help in the fight against malaria.”