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May 29, 2006
Volume 84, Number 22
p. 19

Preventing Malaria

Insecticide-treated nets are playing an important role in fighting malaria in Africa, Southeast Asia

Jean-François Tremblay

Improving lives and creating jobs: That is what many chemical companies claim their products do. But by manufacturing its Olyset antimalaria nets, Sumitomo Chemical is clearly helping to save thousands of lives, while employing hundreds of people.

Net Sumitomo Chemical Photo

DOORKEEPER Long-lasting insecticide-treated nets can be put over beds or in doorways.

According to the World Health Organization, malaria kills nearly 1 million children annually in Africa alone. The mosquito-transmitted disease is also present in many Asian countries. The organization considers fighting malaria one of its top priorities.

Over the years, says Ikuzo Ogawa, head of planning in Sumitomo Chemical's agricultural chemicals division, WHO has fought malaria in various ways. It has tried spraying the walls of homes in areas where malaria is a problem. The agency has also treated mosquito nets with pesticides by means of spraying or dipping.

Tests conducted by WHO in the 1980s and 1990s show that insecticide-treated mosquito nets cut malaria-related mortality in children by 20%. But, Ogawa says, the insecticide in a net that has been dipped or sprayed loses its efficacy after a few months. And it has proven difficult to convince African villagers to re-treat their nets every few months, WHO reports.

Sumitomo initially aimed its special insecticide-impregnated nets at the Southeast Asian agricultural market, where they were meant to protect fruit from pests. Launched in 1992, the nets did not sell as well as expected.

Pierre Guillet, the vector control specialist at WHO's global malaria program in Geneva, recalls that Sumitomo reacted hesitantly when told that its nets could be used to fight malaria.

He notes that the market for malaria-combating products is traditionally one where risks are high and rewards low. Companies are averse to be seen as profiting from the scourges affecting developing countries, he says. Accidents or safety problems attract intense media attention, and products are typically bought in a public bidding process that often lowers margins.

In contrast with Sumitomo, the Vestergaard-Frandsen group, a Swiss supplier of disease-control textiles, intensely promoted its PermaNet antimalaria nets, Guillet says. He adds that the polyester nets made by Vertergaard are more agreeable to the touch than Sumitomo's, but they last only two to three years when used in field conditions. The Sumitomo ones are tougher and are effective for up to seven years.

Spurred by WHO, Sumitomo's net production has rapidly increased in recent years. Ogawa expects that Sumitomo and its joint-venture partners will produce 30 million nets in 2007, up from about 20 million this year. Each Olyset net costs roughly $6.00, a dollar more than the Vestegaard ones.

Sumitomo's nets are made in Shanghai and Dalian, China; Arusha, Tanzania; and Vietnam. The plant in Arusha is a joint venture with a local partner, A to Z Textile Mills. Elsewhere, the plants are toll manufacturers hired by Sumitomo. The company is looking for partners to begin production in Kenya, Rwanda, Cameroon, Senegal, or Zimbabwe.

The main material used to make the nets is high-density polyethylene fiber, which is instilled with the insecticide permethrin in a proprietary process. Ogawa says that stitching is labor intensive, employing up to 150 people for every million nets produced per year. The nets have large pores, he says, to ensure good ventilation, a property that is critical in hot climates.

The nets are primarily bought by national governments, Guillet says. He adds that WHO's endorsement of nets from both Sumitomo and Vestergaard has created waiting lists of six months for either of the products.

The malaria net business does not contribute to Sumitomo's bottom line, Ogawa says, and is operated as part of the firm's corporate social responsibility initiatives. The cash they generate is mostly invested in expanding production of them. Earlier this year, Sumitomo agreed to give away 330,000 nets worth $2 million to Millennium Promise, a nonprofit group fighting extreme poverty that is led by Columbia University Professor Jeffrey Sachs.

Guillet believes the market is better supplied if companies operate on the basis of profit maximization. The shortage of long-lasting antimalaria nets has spurred seven companies to submit competing products to WHO for evaluation, he says, and two of them are very similar to Sumitomo's Olyset nets. WHO will complete its evaluation of the nets in December 2007, Guillet expects.

But for the time being, Sumitomo can enjoy the recognition that comes with being a key supplier of an important malaria-fighting tool.

Chemical & Engineering News
ISSN 0009-2347
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