In 2009 some 225 million people – nearly 80 percent of them from Africa – contracted malaria. Around 781,000 of these people, including a large number of children under 5, subsequently died of the disease (Source “World Malaria Report”, WHO 2010). In several African countries, such as Ethiopia, Uganda, Zambia and Malawi, Bayer for many years has participated actively in the fight against malaria, which is transmitted by the Anopheles mosquito. Two projects give special grounds for hope. A bed net sets new standards in prophylaxis and in active substance research the foundations have been laid for a breakthrough in the fight against the insects which transmit malaria.
Zoom imageBed nets which are impregnated with an insecticide can help reduce infections by mosquitoes, which carry malaria, by up to 50 percent. The nets have to remain fully effective after 20 washes which corresponds to roughly three years use.
Declaring war on malaria
It happens thousands of times, night after night, in Africa: Anopheles mosquitoes settle on sleeping people, bite them and suck up their blood fiand in doing so transmit the malaria parasite. One bite is enough and the disease spreads through the body. Bayer CropScience declared war on malaria long ago.
The Environmental Science Business Group therefore offers a large number of products and strategies to control the vectors, including tabs containing the insecticidal active ingredient deltamethrin with which to impregnate bed nets, and formulations for fumigating houses.
Now Environmental Science has opened up a new chapter in the fight against malaria, focusing on mosquito nets. To protect people against the mosquitoes which transmit the disease, the World Health Organization (WHO) is promoting Long-Lasting Insecticidal Nets (LLINs), which have an insecticide incorporated into the fibers of the nets.
Environmental Science has opened up a new chapter in the fight against malaria, focusing on mosquito nets.
With these, the chance of infection can be reduced by up to 50 percent. The WHO makes stringent demands on the nets. They have to remain fully effective after 20 washes - which corresponds to three years’ use. “We far exceed this requirement with our LifeNet™,” says Dr. Rainer Sonneck, Head of Product Development for Pest and Vector Control, not without some pride. The bed net which has been developed will withstand 35 washes and can be used for five years. It is also more tear-proof, softer and more user-friendly than other comparable products.
The reason for these improvements is that instead of polyester or polyethylene, the scientists have used polypropylene for the first time as the basis of the fabric. A use with which they had no previous experience whatsoever, emphasizes Rainer Sonneck.
The first challenge was to produce thin polypropylene threads and then to scale this up for mass
production. The weaving process then had to be adapted. Finally, a method of incorporating the
insecticidal active substance directly into the polypropylene fibers had to be found.
Environmental Science looked to collaboration with Bayer Technology Services for this and, together, they developed a completely new technology. For Ildem Bozkurt, Project Manager in the field of vector control at Environmental Science, the LifeNet™ represents a logical development: “Bayer CropScience
has played a key role in the developm nt of insecticide-treated nets. Today, our insecticides are used
in a broad range of nets. The LifeNet is the logical progression.” The net is currently being tested by the WHO in Africa and India and preparations for market launch are also under way. Bayer CropScience is also working closely on another ambitious project with the Innovative Vector Control Consortium (IVCC), an affiliation of leading institutions in the field of product development and information systems for improved vector control.
The aim of this collaboration is to find active substances with novel mechanisms of action
against malaria mosquitoes, which are resistant to conventional insecticides. The active substances will be used as “Public Health Products” to protect the health of the public at large. Since the middle of 2009, eleven members of staff have been working on the project which is scheduled to last three years. In the first year, the substances stored in the Bayer CropScience substance library underwent repeat-screening. Any substances which were identified as being active against mosquitoes were optimized and tested for efficacy. “Four new chemical classes and their modes of action were identified. Now the chemists are starting to synthesize derivatives,” explains Rainer Sonneck. The importance of the project is huge: no new mode of action against mosquitoes has been introduced for 60 years – and no new active ingredients for two decades. Although as Dr. Sonneck emphasizes, the researchers still have a long way to go. “We are just at the beginning,” he says.