DDT was widely used to control malaria and louse borne typhus fever in the 1940s through 1950s. At the time, it was rated as the most effective insecticide ever synthesized by man. It was largely effective in eliminating mosquitoes and lice; vectors responsible for the transmission of malaria and typhus fever respectively. However, its fortunes began to dwindle in the 1960s when environmental lobby groups began to advocate for its withdrawal from the market. Its use was eventually banned in the United States and other countries.
In the early 1960s, various reports indicated that DDT was not a safe insecticide. It was reported that the chemical harmed animals and birds as well. Of particular concern was the migration of birds occasioned by lack of food. It was reported that the population of some birds in certain parts of the United States had reduced.
Other negative effects like thinning of egg shells were also reported. Pollution of water resulted in fish poisoning. Insect resistance to the compound was also reported around the same time. Mosquitoes were increasingly becoming resistant to DDT. These reports were a clear indication that eradication of malaria was going to be almost impossible.
The publication of Rachel Carson’s book titled the Silent Spring only made matters worse for the malaria eradication program. After the publication of the book environmental lobby groups emerged. Their activities led to the establishment of the Environmental Protection Agency (EPA) in the United States. Establishment of this agency became a turning point in the fight against malaria.
Fred Soper believed that the global malaria eradication program failed due to administrative problems. According to him, eradication of mosquitoes needed hard work and discipline. He also pointed out that his principles were being applied incorrectly. The field officers did not spray long enough to eradicate the parasites.
In addition, health officials did not understand the malaria control program well. Field officers/inspectors took bribes and in some cases they compromised the concentration of the insecticide. Though his observation was accurate, there were other factors that contributed to the failure of the program. For instance, the program had ignored other supplementary control measures like environmental modification.
DDT should be revived as an approved insecticide. However, approval should be restricted to some areas and uses. To date, DDT remains the only effective chemical against mosquitoes. Soper’s plan was to eliminate mosquitoes that came in contact with the malaria causing parasite.
If spraying had been done long enough, the remaining population of mosquitoes would have become free of the parasites. Reintroduction of DDT in malaria endemic zones will facilitate the elimination of both the pathogen and the insect without harming humans. Current malaria control programs are both expensive and ineffective.
For example, mosquitoes have become resistant to mosquito repellants. Use of insecticide treated nets is very expensive and appears to be unsustainable in poor countries. Plasmodium parasites have also become resistant to most anti-malarial drugs.
Every year, more than one million deaths can be directly linked to malaria. Most of these deaths occur in the poorest nations. More than half occur in Sub-Saharan Africa. Children make up a greater portion of the fatalities. To reduce or eliminate these unnecessary deaths, poor countries have to be allowed to use DDT to control mosquitoes. However, use of DDT as an agricultural insecticide should remain illegal. It was the use of DDT as an agricultural pesticide that triggered the debate on its safety.