International advocacy against DDT and other public health insecticides for malaria control

Abstract

A new international effort to control/eradicate malaria is accompanied by suggestions that malaria can be controlled without the use of dichloro-diphenyl-trichloroethane (DDT) and other insecticides. We review the underlying science of claims publicized by the Global Environment Facility (GEF), the United Nations Environment Programme, and the Stockholm Convention Secretariat (the Secretariat). Their claims stem from a $14 million GEF project that was conducted from 2003 to 2008 in Mexico and seven countries of Central America. Objectives, experimental design, analyses, and project accomplishments are described. So-called environmentally sound interventions (GEF interventions) that excluded insecticides were implemented in demonstration areas in eight countries. Efficacy of interventions was evaluated by comparing malaria rates in demonstration areas (n = 202) with those in control areas (n = 51), all in high malaria risk areas. There were no statistically significant reductions in malaria rates in demonstration areas compared with controls. This was true across all eight countries. Broad use of antimalarial drugs was the primary method of malaria suppression in the eight countries, but this method was not a GEF intervention. Ultimately statistics favoring efficacy of "environmentally sound" methods of malaria control were obtained by comparing malaria cases in demonstration areas for 2004 with cases in 2007, and we explain why these comparisons are not valid. In conclusion, claims that GEF interventions effectively reduced malaria in Mexico and seven countries of Central America are not supported by existing data or the results of epidemiological analyses. The claims are being used to justify the Secretariat's plan to eliminate DDT production by 2017. DDT is still needed for effective control of malaria, and its elimination could have significant consequences for people in malaria endemic countries.