Eradication of Anopheles gambiae from Brazil: lessons for malaria control in Africa?

Current malaria-control strategies emphasise domestic protection against adult mosquitoes with insecticides, and improved access to medical services. Malaria prevention by killing adult mosquitoes is generally favoured because moderately reducing their longevity can radically suppress community-level transmission. By comparison, controlling larvae has a less dramatic effect at any given level of coverage and is often more difficult to implement. Nevertheless, the historically most effective campaign against African vectors is the eradication of accidentally introduced Anopheles gambiae from 54000 km(2) of largely ideal habitat in northeast Brazil in the 1930s and early 1940s. This outstanding success was achieved through an integrated programme but relied overwhelmingly upon larval control. This experience was soon repeated in Egypt and another larval control programme successfully suppressed malaria for over 20 years around a Zambian copper mine. These affordable approaches were neglected after the advent of dichlorodiphenyl trichloroethane (DDT) and global malaria-control policy shifted toward domestic adulticide methods. Larval-control methods should now be re-prioritised for research, development, and implementation as an additional way to roll back malaria.