The project, run by the Malaysia-based WorldFish Center and targeted at families where some members have died from AIDS or are suffering from the epidemic, has doubled income for 1,200 families in Malawi and improved diets, WorldFish said.

"These small fish points offer tremendous benefits to struggling farming families in rural Africa whose many challenges have been greatly compounded by AIDS," Stephen Hall, director general of WorldFish, said in a statement.

Many families in the project were headed by widows or grandparents caring for orphans.

About one in five adults in Malawi, among the world's poorest nations, are infected with HIV/AIDS and tens of thousands of the 12.1 million population die every year from the disease. A cocktail of drugs can help control infection, but there is no vaccine and no cure.

WorldFish, a non-profit research group, said it was expanding the scheme to neighbouring Mozambique and Zambia with a goal of reaching 26,000 households.

"We hope to reach this goal within 2 to 3 years. We have also received requests for information from as far as Nigeria," Daniel Jamu, the regional director for WorldFish in eastern and southern Africa, told Reuters.

WorldFish is backed by the Consultative Group on International Agricultural Research and World Vision, an aid group.

Farmers are encouraged to use farm waste and crop by-products to feed their fish. In turn, the fish farms are twinned with a drive to get farmers to grow more vegetables, using pond sediment as fertiliser.