After initial success with malaria control in the 1960s, Vietnam experienced a resurgence of malaria from the late 1970s until 1991, when malaria peaked at over a million cases and 5,000 deaths. Responding to this deadly outbreak, the government of Vietnam shifted away from their DDT-based malaria eradication strategy to a malaria control approach that allocated significantly more funds to the program, distributed drugs and free or subsidized mosquito nets in the neediest areas, carried out twiceyearly home insecticide spraying with pyrethroid insecticides, and provided intensive health education. Health education efforts involved village leaders, the Women's Union cadres and commune health staff, as well as mobilization by local trainers of communities in high risk malaria areas. By 1997, this integrated, community-based approach reduced malaria deaths by 97% (from 5,000 to 190) and malaria cases by 59% (from over 1 million to 348,500; 1,350 of these severe).
Mexico's successful national malaria control program includes a combination of nonchemical and chemical control measures. Currently, Mexico uses an integrated vector and malaria management approach that includes: a) epidemiological surveillance that allows early detection of the malaria cases and prompt medical treatment, b) community participation in the notification of the cases and in the cleaning of the streams where the mosquito eggs are; and c) chemical control with pyrethroids. Specific chemical controls include the pesticide deltamethrin indoors, outdoor spraying of permethrin, and use of a low volume yet effective spray technology for application of these pesticides. DDT has not been used in Mexico since 2000.
India, which spends one-third of its national health budget on malaria control, is an important case study on alternative approaches to malaria control. In 1997, the World Bank approved $164 million for the Malaria Control Project in India to promote alternatives to indoor spraying of DDT. Alternatives include selective vector control using targeted spraying, non-insecticide methods such as larvae-eating fish and biological larvicides, more environmentally friendly pesticides, medicated mosquito nets and institutional strengthening. Biological larvicides and polystyrene beads (used to kill mosquito larva and pupa) have proven highly effective. In the Hassan district in Karnataka and in Maharashtra bioenvironmental methods have reported up to a 70% reduction in malaria cases. The success of these alternative approaches is critical in a country where the rural mosquito vector that transmits 65% of malaria is resistant to DDT and at least two other pesticides.
For more case studies and additional information on malaria control, see PAN North America's DDT and Malaria Resource Center.
1.World Health Organization. A Story to be Shared: The Successful Fight Against Malaria in Vietnam, 2000, http://www.afronets.org/files/malaria.pdf, p14.
3. González FB, The Phasing Out of DDT in Mexico, Pesticide Safety News, 2001 Milan, Italy, International Center for Pesticide Safety 5(2):5, 2001; and Situacion actual de la malaria y uso del DDT in Mexico. Centro Nacional de Salud Ambiental. Centro de Vigilancia Epidemiologica. Secreteria de Salud. Diciembre 2000; and Participación ciudadana y alternativas al DDT para el control del la malaria. Memorias. RAPAM.World Wildlife Fund. Julio 1998. Texcoco, México.
4. Project Appraisal Document on a Proposed Credit in the Amount of SDR 119.2 Million to India for a Malaria Control Project. May 15, 1997. The World Bank, Population and Human Resources Operations Division, Country Department II, South Asia Region Report No 16571 - IN.
5. Sharma VP and Sharma RC, Cost Effectiveness of Bioenvironmental Control of Malaria in Kheda District of Gujarat, Indian Journal of Malariology, 23(2):141-145, 1986; and Sharma VP Laboratory experiments on the effectiveness of Expanded polystyrene beads in mosquito control, Indian Journal of Malariology, 21:115-118, 1984.
6. Agarwal R, No Future in DDT: A Case Study of India, Pesticide Safety News, 2001 (Italy).