Environmental Management for Vector Control
WHO defines Environmental Management for Vector Control as the planning, organization, carrying out and monitoring of activities for the modification and/or manipulation of environmental factors or their interaction with man with a view to preventing or minimising vector propagation and reducing man-vector-pathogen contact. It may entail one of two options (or both): environmental modification (permanent infrastructural changes of a capital-intensive nature) and environmental manipulation (recurrent actions aimed at achieving temporary unfavourable conditions for vector breeding).
WHO has, for many years, worked with FAO and UNEP on the promotion of EMVC and continues to promote it as part of Integrated Vector Management. Current activities of the WHO Water, Sanitation and Health Programme include the development of a methodology to estimate the fraction of the burden of vector-borne diseases that can be attributed to components of water resources development and the promotion of good practice in water management and other environmental management approaches. WSH also provides inputs into WHO’s Malaria programme and links with the CGIAR System-wide Initiative on Malaria and Agriculture (SIMA).
Since Environmental Management was the mainstay of vector-borne disease control in the pre-DDT era, several historic reviews have highlighted the potential of this approach in the reduction of reliance on pesticides. WHO/WSH will initiate the production of a CD-ROM containing such grey literature on the history of Environmental Management.
Burden of Disease work
Assessing the burden, analysing the cost-effectiveness of intervention options
Including environmental management measures as health safeguards in water resources development projects requires action and investment from outside the health sector. Ministries of agriculture, energy or water resources, local authorities or private corporations need to be convinced, with solid evidence, that it is worth investing in health. And that such investments translate in greater chances of success, sustainability and, ultimately, economic return of their projects.
It is therefore crucial that the health benefits of such measures (and the costs of not including them) are translated into economic terms that can be part of a larger balance sheet of investments and returns. With a view to providing a methodology to analyse the cost-effectiveness of environmental management as compared to other vector control and disease control measures in specific settings, guidelines (PEEM 3) were developed.
WSH has now embarked on a study, commissioned from the Swiss Tropical Institute in Basel, to develop a methodology of estimating the relative burden of vector-borne diseases as it is associated with components of water resources development. The four diseases covered are malaria, schistosomiasis, lymphatic filariasis and Japanese encephalitis.
Water management for vector control
Many insect vectors of the most important parasitic diseases are linked to aquatic ecosystems. Three important categories can be distinguished: natural water bodies, man-made water bodies and water bodies in the human settlement and household environment.
The creation of man-made water bodies often results in hydrological changes that favour intensified vector breeding, or shifts in local vector species composition. Many are linked to project of an infrastructure development nature. The World Bank and WHO recently reviewed the situation in this respect for the East Asia and Pacific Region, and published the outcome of the review in a World Bank HNP Discussion Paper
Rolling back malaria
WSH and the Roll Back Malaria Initiative have worked closely together during the negotiations over the Convention on Persistent Organic Pollutants (POPs). Now known as the Stockholm Convention, it provides an international, legally binding instrument for the reduction and elimination of compounds labelled as POPs. The initial list of 12 POPs covered by the Convention includes DDT, still in use by a number of countries for indoor residual spraying to reduce malaria transmission. The Stockholm Convention is currently awaiting ratification by sufficient governments for it to take effect.
In support of the process of negotiation and ratification, WSH and RBM prepared a number of documents, two of which have been published: the WHO DDT Action Plan and a guidance document on alternatives to POPs pesticides. Guidelines for Vector Control Needs Assessment still are in preparation.
System-wide Initiative on Malaria and Agriculture (SIMA)
Collaboration with individual institutions belonging to the Consultative Group on International Agricultural Research (CGIAR), such as IRRI, IWMI, WARDA and ISNAR resulted in 2000 in the establishment of the System-wide Initiative on Malaria and Agriculture (SIMA). WSH works with SIMA on the promotion of research relevant to improved environmental management in agro-ecosystems.
SIMA’s goal is to achieve malaria reduction resulting in improved health and well-being, agricultural productivity, and poverty alleviation. It aims to achieve this goal by developing and promoting methods and tools for malaria control through improved agricultural practices and proper management and utilisation of natural resources, that will be based on scientifically documented interactions between agricultural production systems and malaria, and that will complement existing anti-malaria approaches.
The International Water Management Institute provides the Secretariat for SIMA, which is based at IWMI Regional Office for southern Africa in Pretoria, South Africa.