Malaria is one of last three major epidemics, killing well over a million people a year globally. Only AIDS and tuberculosis claim more victims. Malaria is caused by tiny single-celled organisms called plasmodia transmitted by mosquitoes of the Anopheles genus. Around the world, every two minutes a child dies from malaria and it is also a major cause of global poverty and its burden is greatest among the most vulnerable.
For decades now, BASF has committed itself to the fight malaria and other tropical diseases. The company’s latest contribution- Interceptor, a mosquito net coated with a novel insecticide has received a recommendation from the World Health Organization (WHO) according to a report on its website.
Till date, pyrethroids nets have been the only ones deemed safe enough to use in nets. Since the resistance to the pyrethoids in malarial mosquitoes has now become common across Africa, development of new types of insecticides safe to use is being attempted.
The research was conducted by the London School of Hygiene & Tropical Medicine, working in partnership with BASF SE to develop and evaluate the new type of net, Interceptor G2.
The net combines two insecticides: chlorfenapyr and the pyrethroid alpha-cypermethrin in a long-lasting wash resistant formulation.
Long-lasting insecticide treated nets (LLIN) that kill the Anopheline mosquitoes which transmit malaria are the most widely used method to prevent the disease. Over half the population of sub-Saharan Africa now sleep under LLIN and this has helped to reduce malaria cases by a third over the last 15 years.
BASF’s new net based on chlorfenapyr, which has been used in agriculture and urban pest control for over two decades, has been reworked to make it effective on mosquito nets and meet targets for the public health market.
The researchers found that in most cases even brief contact with the net is sufficient to seal a mosquito’s fate- within as little as five minutes after contact, the insect drops paralyzed to the floor, an effect known as knockdown.
Interceptor easily satisfies all the WHO requirements for an officially time limited interim recommendation as an LLIN. And the WHO sets very high standards. Even after 20 washes, the knockdown must still be at least 95 percent and the mortality rate 80 percent. Senior investigator Dr. Vincent Corbel of the Institut de recherche pour le développement in Montpellier – officially commissioned by the WHO to test the net – reached the conclusion: “Interceptor exceeds 95 percent knockdown even after 25 washes. And the net is fully ready for use again the very next day after washing.”
Professor Mark Rowland, Research Coordinator and study author, said: “Our results are extremely encouraging and represent an important breakthrough in long lasting net development. We found that in field trials under household conditions the new net killed over 70% of pyrethoid-resistant Anopheles gambiae mosquitoes that entered the houses to feed, whereas the standard pyrethroid net killed only 20%. The mosquito mortality rates achieved by the new net are similar to those seen with the standard pyrethroid net 10 years ago, when mosquitoes were fully susceptible to pyrethroids before resistance began to take hold.
“Very importantly, the long lasting formulation retained insecticidal activity on the net after 20 washes in soap solution, which meets the WHO benchmark for long lasting insecticide treated nets.”
Following the WHO recommendation, BASF will start preparations to launch Interceptor G2 and depending on local registration processes, the new mosquito net is expected to be available to health ministries and aid organizations starting towards the end of this year.
“New resistance management products are desperately needed to prevent mosquito-borne diseases and save lives,” said Egon Weinmueller, Head of BASF’s public health business. “This development breakthrough strengthens my personal belief that we really can be the generation to end malaria for good.”