International Programme on Chemical Safety

Strengthening malaria control while reducing reliance on DDT

Updated March 2011

Dr B. Ameneshewa

WHO is currently facing a double challenge - a commitment to the goal of drastically and sustainably reducing the burden of vector-borne diseases, in particular malaria, and at the same time a commitment to the goal of reducing reliance on DDT in disease vector control, in line with the Stockholm Convention which entered into force in May 2004.

On 23 May 2007, the World Health Assembly, through Resolution 60.18, requested:

  • international organizations and financing bodies to provide [inter alia] support for the development of capacities in developing countries in order to expand use of: reliable diagnostics, artemisinin-based combination therapies that are appropriate for local drug-resistance conditions, integrated vector management including long-lasting insecticide-treated nets and larvicidal measures, indoor residual spraying with appropriate and safe insecticides as indicated by WHO and in accordance with the Stockholm Convention on Persistent Organic Pollutants, and monitoring and evaluation systems, including use of the country database developed by WHO; and
  • the Director-General [inter alia] to support the sound management of DDT use for vector control in accordance with the Stockholm Convention on Persistent Organic Pollutants, and to share data on such use with Member States.

WHO promotes integrated vector management (IVM) as the approach of choice to control transmission of malaria and other vector-borne diseases. A key element of IVM is a solid evidence base for the effectiveness of combinations of locally-adapted, cost-effective and sustainable vector-control methods. This approach will facilitate sustainable transition away from DDT.

In some countries, local conditions have made it possible to reduce or eliminate reliance on DDT. In other countries, at this time, the use of DDT for Indoor Residual Spraying (IRS) remains indicated. In such cases, DDT use should be managed in the context of the Stockholm Convention and following WHO recommendations.

Because of its persistence, DDT tends to accumulate in the environment and in humans. Scientific evidence on the toxicity of DDT and its primary metabolites, DDE and DDD, including the most recent scientific publication, is kept under review by WHO.

The most recent WHO evaluation, DDT in indoor residual spraying: Human Health Aspects, was conducted by an Expert Consultation and published in March 2011. It concluded that in general, levels of DDT exposure reported in studies were below levels of concern for health. In order to ensure that all exposures are below levels of concern, best application measures must be strictly followed to protect both residents and workers. WHO's recommendations on the use of DDT for IRS1 and WHO's position on the safety and use of DDT for IRS2 will be revised if new information on the potential hazards of DDT becomes available, justifying such a revision.

WHO is working with countries and partners to strengthen capacities to plan, implement and evaluate integrated vector management, to develop, test and introduce chemical and non-chemical alternatives to DDT, and to improve the use and management of insecticides for vector control. WHO is working with the Secretariat of the Stockholm Convention to support Member States in complying with the obligations of the Convention, including reporting on the use of DDT for vector control.

1 World Health Organization. Indoor Residual Spraying. Use of indoor residual spraying for scaling up global malaria control and elimination. WHO Position Statement Series 1112, Geneva, World Health Organization, 2006.

2 World Health Organization. The use of DDT in Malaria Vector Control. WHO position statement series, Geneva, World Health Organization, 2011.