Malaria in the Thar Desert: Facts, Figures and Future - Book review

One usually does not associate malaria with a desert environment. Common sense dictates that mosquitoes, that breed only in stagnant water, would give arid, water-scarce spaces such as a desert a wide go-by. But that is not the case in the Thar desert. Rajasthan, India, is also the land of persistent desert malaria

 
Published: Wednesday 30 April 2003

-- Malaria in the Thar Desert: Facts, Figures and Future By B K Tyagi Published by Agrobios (India) Jodhpur 2002 Rs 495

One usually does not associate malaria with a desert environment. Common sense dictates that mosquitoes, that breed only in stagnant water, would give arid, water-scarce spaces such as a desert a wide go-by. But that is not the case in the Thar desert. Rajasthan, India, is also the land of persistent desert malaria.

The Thar Desert has a unique ecosystem. But over the last two decades, its physiography has undergone a major change. What precisely changed? And what is the relation between this change and the transformation of malaria from an occasional to a persistent, endemic disease? The book provides a simple, yet startling answer: extensive canalisation.

There are three major canals in the Thar Desert: The Ganga canal, the Bhakra-Sirhind canal and the Indira Gandhi Nahar Pariyojana , regarded as one of the world's most gigantic projects of its kind in a desert ecosystem. Though these projects were set up with good intentions -- they would provide a fillip to irrigation, allow more crops to be grown, and solve the water problem of the region -- they also brought with them swarms of mosquitoes. Drastic changes began to occur in the ecosystem: increase in the water table, water logging, and a change in the rainfall pattern along with relative humidity were observed.

The year 1990 was very crucial. The Thar was hit by a major epidemic, recording about 48 deaths. Another major epidemic happened in mid-1994, and the toll was more than double than that of the 1990 epidemic. Canalisation apart, lack of malaria-related immunity among villagers and the development of resistance against insecticides as well as drugs in the malarial mosquito species further aggravated the epidemic.

This book interprets Thar malaria as a model. It seeks to understand the correlation between the xeric environment -- and the changes brought about by extensive canalisation -- and prevalence of a disease. The Thar malaria model, the book suggests, is also helpful in understanding water management for the control of vectors and their composition.

The book also provides a comprehensive description of the malaria programme in India. The first national programme for malaria control was initiated in 1953 with comprehensive indoor residual spray of ddt. Initially the methodology focused on control. Then two problems occurred: the malarial parasites became drug-resistant and mosquitoes became immune to ddt. Even so, the programme was deemed successful and, in 1958, its focus was shifted from 'control' to 'eradication'. But the twin problems continued. By 1977, realisation struck that malaria could not be eradicated. So government launched 'the modified malaria programme'. The focus was 'containment'. Along with this, there were sub-programmes with specific targets: attacking the most prevalent parasite in an area, or programmes geared for urban areas, the 'Urban Malaria Scheme'. After a long struggle to create an appropriate programme, the 'Enhanced Malaria Control Programme' was launched in 1997. In 1998, the World Health Organization also launched the 'Roll back Malaria' for southeast Asia: its target is malaria control by 2010. This programme is primarily for the southeast Asia region.

Reading through this history, one gets the clear sense that semantics is often more important than dealing with the disease. Effectively it is more about the politics of naming. But the book unfortunately does not go into this. It prefers to be diplomatic. Nevertheless, it is useful to find so much detail within a single volume. Equally useful is the bibliographical information of various studies in the field of malaria.

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