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How DDT can stop millions of malaria deaths

Every year, more than a half-a-billion people suffer agonising pains and fevers because of malaria, a disease that is entirely preventable and curable. In Africa, someone -- normally a child -- dies every 30 seconds from this disease, causing unimaginable grief, human suffering and economic stagnation.

Every year, more than a half-a-billion people suffer agonising pains and fevers because of malaria, a disease that is entirely preventable and curable. In Africa, someone—normally a child—dies every 30 seconds from this disease, causing unimaginable grief, human suffering and economic stagnation.

It needn’t be this way, however; about 50 years ago, malaria was eradicated from Europe and the United States, and right now some countries have successful anti-malaria programmes. Yet, far from helping countries with malaria, many donor agencies and United Nations organisations actually hamper the fight against the disease and the deadly mosquitoes that transmit it. 

One of the best ways of controlling malaria is to use the insecticide that most environmentalists love to hate—DDT. If mosquitoes and parasites were not enough to contend with, the politics surrounding the use of DDT and vested interests that oppose it make it nearly impossible for countries to use DDT for malaria control in spite of its incredible success.

DDT was first used during World War II to halt the spread of lice-borne typhus. Typhus epidemics raged in many war-torn areas. DDT powder was dusted over civilians, soldiers and concentration-camp survivors and put in their clothes and bedding, and before long the spread of the disease was halted.

Malaria-control experts soon noted the success of DDT in typhus control and began to apply the insecticide against mosquitoes. When used in malaria control, DDT is sprayed in tiny quantities on the inside walls of houses. This application repels mosquitoes so that they don’t enter houses to feed on humans, and kills them if they do enter.

Indoor residual spraying (IRS) with DDT eradicated malaria in the US and Europe and led to spectacular declines in the disease in Africa, Asia and Latin America. Wherever DDT was used in public health, death and disease fell and the conditions for development and wealth creation improved.

But while DDT was saving lives in malaria control, it was also being used in agriculture. Sprayed in enormous quantities aerially, DDT protected crops from pests like boll worm. This use of DDT raised concerns in the early 1960s from the nascent modern environmentalist movement. In her book Silent Spring, Rachel Carson described potentially catastrophic consequences for wildlife and humans of the widespread use of DDT.

US hearings

Growing campaigns by environmentalist groups during the 1960s culminated in the hearings into DDT by the newly formed US Environmental Protection Agency (EPA). After eight months and extensive, in-depth hearings presented with evidence from experts both for and against DDT, the presiding Judge, Edmund Sweeney, ruled that DDT should not be banned. Despite the popular view that DDT was highly damaging to the environment and human health, there was, in fact, little scientific evidence to support these beliefs.

Yet DDT was banned anyway by the head of the EPA, William Ruckelshaus, in a neat example of politics trumping good science. The EPA had just been formed and its head was keen to demonstrate that the agency could and would take decisive actions to protect the environment. The fact that banning DDT wouldn’t actually help the environment was neither here nor there.

Since the EPA banned DDT in agriculture, countless studies have been conducted into the potential impacts of DDT on human health, yet none of them have been able to find any concrete evidence of actual human harm. DDT is remarkably non-toxic to humans; people have tried to commit suicide by eating it and failed miserably. DDT is classified as a possible human carcinogen by the International Agency for Research on Cancer, which may sound alarming, but is the same classification given to coffee and many other foodstuffs in our daily diet.

Even though the evidence of environmental harm from DDT has been exaggerated, the use of DDT in malaria control cannot result in environmental degradation. First, it is used in small quantities indoors. Second, most environmental degradation in malarial areas arises from poverty, an over-reliance on natural resources for food and fuel, and a lack of clearly defined property rights. If DDT spraying can reduce disease and catalyse development, drawing in tourists and investors, the state of the environment is likely to improve.

Dwindling support

The agricultural banning of DDT, in theory, did not affect the public-health use of the insecticide. DDT remained available for use in malaria control; however, the support given to the insecticide and the spraying programmes that used it began to dwindle. Many malaria-control programmes rely on financial, logistical and scientific assistance from donor agencies and the various UN agencies that are involved in malaria control, such as the World Health Organisation (WHO) and the UN Children’s Fund.

Without support from these organisations, maintaining malaria-control programmes became increasingly difficult, and from the 1970s onwards, malaria gradually increased worldwide, claming more and more lives and condemning hundreds of millions to repeated bouts of illness.

South Africa has maintained its IRS programme for decades and used DDT very successfully until 1996, when it was withdrawn in part to comply with WHO resolutions to reduce reliance on the insecticide. The result was one of the worst epidemics in the country’s history.

Tragically, the Anopheles mosquitoes were resistant to the insecticides that replaced DDT. After malaria cases had risen by about 1 000%, South Africa reintroduced DDT in 2000 and in just one year achieved an 80% reduction in cases in KwaZulu-Natal, the worst-hit province. Malaria cases remain at almost all-time lows in the country thanks to DDT.

In 2000, a private mine, Konkola Copper Mine on the Zambian Copperbelt, restarted its IRS programmes using DDT. Malaria control had declined along with the economic fortunes of Zambia in the early 1980s and, as a consequence, the disease had returned with a vengeance to many areas. Yet after just one season of DDT spraying, malaria incidence was halved, and was halved again the following year. So successful has the application of DDT been that the Zambian government restarted its IRS programmes in several other parts of the country.

Uganda has been trying to restart its IRS programme and use DDT. Yet, recently, the European Union threatened to ban Ugandan agricultural exports should the programme go ahead. The EU’s fear that some DDT could leak on to agricultural produce is largely unfounded and ignores the fact that most countries that use DDT have instituted tight controls and strict audits of their malaria-control programmes. The EU position is shameful and a double whammy to the health and development of Uganda.

Importance of IRS and DDT

Fortunately, the Global Fund to Fight Aids, Tuberculosis and Malaria (GFFATM) clearly recognises the importance of IRS and DDT to malaria control, and has therefore been funding several IRS programmes in Southern Africa.

Other donors, such as the US Agency for International Development (USAid), do not have the foresight or good sense of the GFFATM and fail to fund IRS programmes in any significant way. In fact, in 2004, of USAid’s $80-million malaria budget, only $4-million was spent buying commodities such as drugs and insecticide-treated bed nets that could actually save lives.

The vast majority of its budget is spent in the US and used by consultants that fly to Africa to tell malaria-control scientists what to do—but that doesn’t actually buy the tools to do the job. Additionally, USAid promotes bed nets as a malaria-prevention strategy to the near-exclusion of IRS with DDT.

So, when a country wants to improve its malaria-control programme and tries to use DDT, which has been shown time and again to be highly effective, it faces opposition from the well-paid consultants that prefer to promote policies that keep them employed and earning air miles. They also face opposition from the trade-protectionist EU that panders to alarmists and mischievously uses junk science, even though it hampers malaria control and costs lives.

Role of business

The obstacles to good malaria control unfortunately do not end there. Big business also plays a distasteful role in this saga. Recently, the Financial Times reported that Gerhard Hesse, business manager for vector control of Bayer Crop Sciences and a board member of the Roll Back Malaria Partnership, wrote an e-mail to various health academics claiming: “We fully support EU to ban [sic] imports of agricultural products from countries using DDT … DDT remains for us a commercial threat [but] mainly a public image threat.”

Bayer produces alternatives to DDT and clearly attempts to direct malaria-control programmes so that they benefit its bottom line. Recently, the Bill and Melinda Gates Foundation donated more than $50-million to the Innovative Vector Control Consortium to create new insecticides. Regretfully, the commercial-development arm of the project is none other than Bayer Crop Sciences.

New insecticides are enormously important for malaria control, but the existing ones—such as DDT—are working extremely well right now and saving thousands of lives. Many more could be saved if donors, the UN and the private sector start to listen to African malaria scientists and put science ahead of politics and their own vested interests.

A noble attempt is being made to ensure that this happens with the Kill Malarial Mosquitoes Now! declaration, which calls for widespread changes to malaria control and demands that the US government start to spend the majority of its malaria-control budget on insecticides and drugs that will actually save lives.

Recently, Archbishop Desmond Tutu joined a broad array of scientists, public-health experts, human rights advocates and religious leaders in demanding change in malaria control. If the declaration is successful, millions of Africans will be freed from the vice-like grip of this ancient and devastating disease.

Richard Tren is a director and Philip Coticelli is a researcher of the health advocacy group Africa Fighting Malaria. The Kill Malarial Mosquitoes Now! declaration can be downloaded from www.fightingmalaria.org

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