The debate about the use of DDT to deter and kill malaria-bearing mosquitoes continues to rage. PAN recognises the current role of DDT in combating malaria, and supports the internationally-agreed phase-out programme by disseminating information about safer alternatives. At the recent Conference of Parties to the Stockholm Convention two speakers Jorge F. Mendez-Galvan, previously Director of the Mexican Diseases by Vector Control Programme and currently Research Leader in the Children’s Hospital of Mexico, and Enrique G. Loyola-Elizondo representing the Pan American Health Organisation (a regional office of the World Health Organisation), explained how Mexico controls malaria without DDT.

Since 2000, Mexico has eliminated the use of DDT and significantly reduced the incidence of malaria, through a multi-faceted programme involving participation by members of the public, NGOs, the academic community and technical and policy experts. At the time the programme was devised in 1998, DDT had been banned in Mexico for agricultural use, but was still approved for mosquito vector control and was manufactured in one facility, supplying only authorized malaria vector control programmes.

In 1998, a pilot study was undertaken in the state of Oaxaca, an area which had seen a number of malaria outbreaks. The Program of Simultaneous Intensive Actions (PAIS in Spanish) has a focused approach concentrating on those houses within a community that are susceptible to malaria. Mapping of malaria cases showed that 21% of the households presented 78% of malaria cases. The programme includes early identification and treatment of malaria cases, improvements in personal and household hygiene, use of bednets, cutting down vegetation around the home which provides mosquitoes with resting places, painting house walls with calcium hydroxide which acts as a repellent, planting insect-repellent trees, elimination of vector breeding sites and control of larvae using fish.
The key aspect of this programme is personal and community involvement. Some steps taken support individual households to improve personal and household hygiene, giving them some power over their own health. Other steps, such as the control of the breeding sites provide support to involve the whole community.

In particular, focusing on the elimination of breeding sites reduced mosquito density and negated the need for indoor spraying. Volunteers from the community were trained in identification and assessment of breeding sites. Members of the community were deployed to clean up stream beds and eliminate algae. Volunteers also monitored their clean up efforts. Over a three year period, the measures resulted in a 70% decrease in larval densities and an 80% reduction in adult mosquitoes.

This programme has achieved a 30% reduction in malaria cases at the village level, and a 50% reduction at the national level.

The Pan American Health Organisation, funded by the Global Environment Facility (GEF) and the UN Environment Programme (UNEP) has been rolling out the Mexican model to eight countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua and Panama.

In the plenary sessions of the Conference of Parties, several governments called for increased research into alternatives to DDT, for increased promotion of success stories, and for improved sharing of experiences between countries in the Global South. The Secretariat proposed a business plan be developed to facilitate the identification and establishment of partnerships for developing and deploying cost effective solutions in malaria control. Several delegates pointed out the urgency of this situation. It is likely that with climate change, the conditions under which malaria carrying vectors (and therefore malaria) flourish will spread to other parts of the world currently malaria free. DDT, as several delegates said, is not a silver bullet. Disseminating information about alternatives and finding further alternatives remains vital to the present and future health of the population of the planet. (LC)