above right: Installing antimalaria netting at roof vents | below right: Netting enveloped around a bed. All photographs Susan Meiselas

Standing water is a breeding ground for mosquitoes and is the main contributor to the spread of malaria. There are 300 million new infections of acute malaria worldwide every year; 90 percent occur in Africa—primarily among children under five.

Treated nets kill mosquitoes on contact, but the cost of re-treating conventional bed nets can be a heavy burden on many families. In 1978 the Sumitomo Chemical Corp. of Japan developed a highly effective insecticide-treated antimalaria bed net that lasted three to five years instead of the usual six months.

In 2001 the World Health Organization initiated a project to manufacture beds using the chemical. But making this lifesaving yet expensive new technology available to as many people as possible posed a challenge. This is where the Acumen Fund, a philanthropic foundation based on a venture-capital model, stepped in.

First the Acumen Fund facilitated the transfer of the technology license and manufacturing contract to Africa’s largest bed-net producer, Tanzania’s A to Z Textile Mills. With investment from Acumen, A to Z purchased equipment to produce about 380,000 bed nets per year. Then, through a public-private partnership between A to Z, the World Health Organization, UNICEF, Exxon Mobil, and Sumitomo, the fund helped create a distribution channel for selling the bed nets at gas stations, clinics, and charitable organizations. The result: an improved product made accessible and affordable to those who need it most.