WHO EXPERT COMMITTEE ON MALARIA
Use of DDT in vector control1
The WHO Study Group on Vector Control for Malaria and Other
Mosquito-Borne Diseases considered the current situation regarding
the use of DDT for controlling vector-borne diseases, in particular
malaria, in the light of two recent publications suggesting an association
between DDT and human cancers (1, 2), a report on the presence
of DDT in breast milk (3), and two general reviews of the subject.2
Two expert toxicologists3
were invited to review these papers, including
the citations, and to participate in the discussions on DDT.
After careful review of the documents and intensive discussion, the
Study Group concluded that:
- The information presented does not provide convincing evidence
of adverse effects of DDT exposure as a result of indoor residual
spraying as carried out in malaria control activities.
- There is therefore, at this stage, no justification on toxicological or
epidemiological grounds for changing current policy (4) towards
indoor spraying of DDT for vector-borne disease control.
- DDT may therefore be used for vector control, provided that all
the following conditions are met:
- it is used only for indoor spraying;
- it is effective;
- the material is manufactured to the specifications issued by
- the necessary safety precautions are taken in its use and
- In considering whether to use DDT, governments should take into
account the following additional factors:
- the costs involved in the use of insecticides (DDT or
- the role of insecticides in focal or selective vector control, as
specified in the Global Malaria Control Strategy (6, 7);
- the availability of alternative vector control methods, including
alternative insecticides (in view of the availability of alternative insecticides for indoor residual spraying, some of
which may compete with DDT in terms of epidemiological
impact, public acceptability, logistic suitability and compliance
with specifications issued by WHO, DDT no longer merits
being considered the only insecticide of choice);
- the implications for insecticide resistance, including possible
cross-resistance to some alternative insecticides;
- the changing public attitude to pesticide use, including public
- Given the paucity of data suggesting adverse effects of indoor
house-spraying, further epidemiological investigation using rigor-ous
scientific protocols is to be encouraged.
- Further studies should also be carried out to:
- examine the health effects of DDT in breast milk on breastfed
infants, including any resulting behavioural change;
- investigate thoroughly any suspected association between the
use of DDT in routine malaria control activities and an
increased incidence of cancer(s);
- clarify the significance of the reduction in muscarinic receptor
density caused by DDT.
1. Garabrant DH et al. DTT and related compounds and risk of pancreatic
cancer. Journal of the National Cancer Institute, 1992, 84:764–771.
2. Wolff MS et al. Blood levels of organochlorine residues and risk of breast
cancer. Journal of the National Cancer Institute, 1993, 85:648–652.
3. Bouwman H et al. Levels of DDT and metabolites in breast milk from
Kwa-Zulu mothers after DDT application for malaria control. Bulletin of the
World Health Organization, 1990, 68:761–768.
4. The place of DDT in operations against malaria and other vector-borne
diseases. In: Executive Board Forty-seventh Session, Geneva, 19–29 January
1971, Part II. Report on the proposed programme and budget estimates for
1972. Geneva, World Health Organization, 1971 (Official Records of the
World Health Organization, No. 190):176–182.
5. Specifications for pesticides used in public health, 7th ed . Geneva, World
Health Organization, 1997 (unpublished document WHO/CTD/WHOPES/97.1;
available on request from the Documentation Centre, Communicable
Diseases, World Health Organization, 1211 Geneva 27, Switzerland).
6. A global strategy for malaria control. Geneva, World Health Organization,
7. Implementation of the Global Malaria Control Strategy. Report of a WHO
Study Group on the Implementation of the Global Plan of Action for Malaria
Control 1993–2000. Geneva, World Health Organization, 1993 (WHO
Technical Report Series, No. 839).
1 Reproduced, with minor editorial changes, from Vector control for malaria and other
mosquito-borne diseases. Report of a WHO Study Group. Geneva, World Health
Organization, 1995 (WHO Technical Report Series, No. 857).
2 Prepared by: Dr C.F. Curtis, Department of Medical Parasitology, London School of
Hygiene and Tropical Medicine, London, England; and Professor J. Mouchet, French
Institute for Cooperative Scientific Research for Development (ORSTOM), Paris, France.
Dr W.N. Aldridge, The Robens Institute, University of Surrey, Guildford, England; and
Professor M. Lotti, Institute of Occupational Medicine, University of Padua, Padua, Italy.
Reproduced with courtesy of Roll Back Malaria
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