The malaise of malaria

Malaria, prevalent in over 100 countries, poses a risk to some 2,700 million people across the world. The direct and indirect economic cost of the disease in Africa alone was over US $1,800 million in 1995.

Ronald Ross, a British officer in the Indian Medical Service, made the first breakthrough in research on malaria control. Despite opposition from his employers, he persevered in his work and was able to show in August 1897 that the parasite was transmitted by mosquitoes.

Ross advocated control of mosquito breeding to control spread of malaria. Opposition to his ideas in the 1930s and 1940s gave a setback to malaria control.

A drive to eradicate malaria was launched in 1955. After initial success, it failed. The disease carrier mosquito, Anopheles , and the malaria parasite, Plasmodium , developed a resistance to insecticides and chloroquine.

Malaria made a comeback in the late 1960s and early 1970s. Attempts to control the second wave of thedisease had limited success. In the late 1970s and the 1980s, chloroquine-resistant Plasmodium spreadfurther in Asia and Africa.

In the 1990s, industrial and agricultural projects in the developing countries have caused ecological changes, favouring transmission of malaria.

In the hundred years since Ross's discovery, one lesson has been learnt: technology alone cannot control the disease. Commitment by governments and peoples is needed.

New areas are being explored to control malaria. The search has followed three distinct lines: conventional methods, such as the use of herb-derived drugs; inno-vative methods, such as the use of insecticide-treated bednets and DNA vaccines; and alternative methods, like genetic engineering to make the mosquito sterile and bioenvironmental vector control.

Each method has advantages and disadvantages. The solution lies in choosing the right combination of methods at the right place and the right time.

The mood of scientists, field workers and adminis-trators at the Second Global Meet on Parasitology with a focus on malaria, held in Secunderabad on August 18-22, 1997, was mixed. New developments present a lot of hope in malaria control, but their implemen-tation requires time, money and commitment.