[Show abstract][Hide abstract] ABSTRACT:
Dichlorodiphenyl trichloroethane (DDT) was at one time highly efficient in malaria control. How-ever, it has lost its effectiveness in vector control and collateral benefits of killing nuisance insects. Malaria control in rural India is based on the indoor residual spraying of insecticides. The princi-pal insecticide used in malaria control is DDT. It has been banned under the Stockholm Convention on Persistent Organic Pollutants under the United Nations Environment Programme (UNEP) auspices in May 2001. The position of the World Health Organization (WHO) for DDT is the mirror image of UNEP. The Stockholm Convention makes provision for the use of DDT in genuine cases. India has sought exemption for the use of DDT in vector control. This article examines the role of DDT in malaria vector control and argues that DDT-spraying produces diminishing returns and eventually becomes counterproductive. Instead, the National Anti-Malaria Programme will do well by abiding with the UNEP/WHO call, reducing reliance on DDT and changing over to the bioenvironmental methods, and investing resources in research and development in the foreseeable future. THE Stockholm Convention on Persistent Organic Pollut-ants (POPs) was signed in May 2001. It bans, inter alia, the use of nine intentionally produced POP chemicals, mostly organochlorine pesticides, including dichlorodi-phenyl trichloroethane (DDT) 1 . It does, however, also contain, in Annex B Part II, conditions under which gov-ernments can be exempted from the ban on use of DDT, for the exclusive purpose of vector control. The Convention establishes as its ultimate goal the complete elimination of DDT production and use, once effective and afford-able alternatives have become available that will allow countries relying on DDT to ensure at least the same level of transmission interruption. Annex 1 of the report of a WHO study group on vector control for malaria and other mosquito-borne diseases 2 provides guidelines on the use of DDT in vector control. Subsequent to these developments, the action plan of WHO for the reduction of reliance on DDT in disease vector control has been published 3 . DDT, at one time considered a panacea, has lost its effectiveness in malaria control. This is partly due to six decades of spraying resulting in physiological resistance to DDT and/or pronounced exophilic vector behaviour en-couraging extra-domiciliary transmission. DDT is still used in malaria control in India, although there is over-whelming evidence of its failure in malaria control. This article examines the value of DDT for future malaria con-trol in India. Data available since the launching of the National Malaria Control Programme (NMCP) in 1953 indicate that while DDT was once extremely effective in controlling malaria, it has lost much of its effectiveness, particularly in the rural areas where most of India's malaria occurs. Even though it may reduce transmission intensity to a sizeable degree in some places, this is not sufficient to prevent epidemics. Moreover, data clearly indicate that in numerous areas subjected to routine spraying of DDT, malaria continues to either stagnate or increase. Much of the ineffectiveness of DDT is the result of resistance in the main rural malaria vector Anopheles culicifacies. Poor operational planning may have contributed to the development of such resistance, and it is unlikely that changes in operational practices will increase the effec-tiveness of DDT. In contrast, there is compelling evi-dence that community-based bioenvironmental methods, particularly when compared to DDT-based house-spraying programmes, are extremely effective in reducing malaria transmission. Accordingly, rather than maintaining or increasing its investment in DDT-based spray programmes, the National Anti-Malaria Programme (NAMP) would do well by increasing its investment in bioenvironmental methods, building on previously demonstrated successes.
[Show abstract][Hide abstract] ABSTRACT:
Malaria is endemic in India and its control has become a formidable task. The Planning Commis-sion of the Government of India estimates that 26.1% of the population of India lives below the poverty line. We have examined during 1999–2000, the status of malaria since 1965 in states below the poverty line. Reduction in poverty to about half since 1970 resulted in improvement in the situation in well-performing states. In contrast, the situation either deteriorated or remained un-changed in states with populations exceeding the national average. Malaria control by chemicals is failing because of its transient nature and the convergence of many inherent technical and financial problems, thus making malaria control more refractory and its treatment enormously expensive. Sustainable control requires that the twin problems of poverty and environment be addressed in a holistic manner. IN the world today 1.3 billion people still live in poverty, 840 million suffer from hunger and 2 billion are mal-nourished 1 . Seventy per cent of the poor are Asians, and half of the developing world's poor live in South Asia 2 . More than half of the world's malnourished and under-weight children live in South Asia. South Asian countries carry the double burden of disease and poverty, establi-shing a seemingly endless vicious circle of disease–low productivity–poverty–disease. Malaria is one of the most important public health problems with which India is confronted perennially, and there are no signs of its abat-ing. Two important vulnerable groups are pregnant women and children under five. It has been shown that pregnant women attract twice the number of mosquitoes than women who are not pregnant 3 . Furthermore, there is a greater susceptibility to P. falciparum than P. vivax dur-ing pregnancy 4 . During pregnancy, malaria has a telling effect on the health of newborn children, for example, malaria is the leading cause of anaemia and low birth weight babies, and such babies are 2 to 4 times more likely to experience failure at school. Malaria affects cognitive development and learning abilities, and poses a risk factor for neurosensory and behavioural development of children 5 . One clinical febrile episode of malaria in terms of food value in adult uses approximately 5000 kcal or the equivalent of 2–3 days of food. The ef-fect of this loss of energy is particularly reflected in the aforementioned vulnerable groups by high mortality due to lowering of immunity, already compromised by ma-laria and the current infection 6 . The return of malaria is impacting all aspects of human and national develop-ment. In this article I have attempted an analysis of the existing malaria situation in India in populations living under extreme poverty.