Mexico has stopped using DDT for malaria control. Speaking at the Health and Environment Ministers of the Americas (HEMA) meeting in Ottawa Mar. 4, Herñando Guerrero said elimination of the tonnes of DDT used annually is a “radical change” that involved thousands of Mexicans at a scientific, health and grassroots level. Guerrero, a director at the Commission for Environmental Cooperation of North America (CEC), said Mexico now combats malaria with a mix of biological, chemical and public-health measures.
“For 40 years we've used DDT, but now we have a sustainable alternative,” he said. Under the new program, 1 Mexican state cut the incidence of malaria from 17 855 cases annually to 284 cases in just 3 years. Pilot projects using the Mexican techniques are now under way in 8 other Latin and South American countries, including Costa Rica and El Salvador, and the project may soon expand to the Caribbean.
The Mexican approach includes early detection and prompt treatment for those exposed, and public education. Volunteers in Mexican communities help eliminate mosquito breeding grounds and deltamethrin, a relatively benign insecticide compared with DDT, is sprayed in some homes. The CEC is also studying the use of nematodes, which attack mosquito larvae.
DDT, outlawed in Canada and the US since the mid-1980s, accumulates in the fatty tissues of animals, and has adverse effects on wildlife reproduction.
Canada's Inuit, who eat traditional diets of mammals and fish, have alarmingly high levels of DDT in their bodies. Dr. David Stone of Indian and Northern Affairs Canada says “Canada is very interested in seeing [the Mexican] experience exported to other parts of the world.” — Barbara Sibbald, CMAJ
Figure. Life-threatening malaria can be prevented without using DDT. Photo by: WHO/Pierre Virot