Health agencies must stop demonising DDT - it saves lives

Roger Bate | 06 Feb 2005
Daily Telegraph (UK)

Headache, high temperature, the shakes, an enlarged spleen and two billion parasites in my liver - that's the price of travelling to Sri Lanka to cover the aftermath of the tsunami.

It was all so different last time: England had just played a great cricket match against the Sri Lankans, the local economy was bustling, and the great threat - from the Tamil Tiger rebels - was waning. Today, the cricket pitch lacks a single blade of grass, the economy is in tatters, and there are more than 31,000 dead from the tidal wave. The only things that remain the same are the heat and humidity.

As I found out the hard way, malaria is back and poised to strike down still more of the children, many orphaned, of this wretched place. It can be stopped, but only if ill-informed prejudice against DDT, the insecticide, is dropped.

Thanks to their food drops and water provisions, a good proportion of Galle's inhabitants have survived the immediate results of the devastation. Nevertheless the malaria-control programme is being compromised.

In a paper entitled "Malaria Risk and Malaria Control in Asian Countries Affected by the Tsunami", the World Health Organisation (WHO) outlines its policy for the affected region. The mistakes in it are being copied by everyone else operating in Sri Lanka and the rest of Asia.

In Sri Lanka, malaria is transmitted by the female Anopheles culcifacies mosquito. The species breeds in rock pools and rice fields, and is a fairly efficient vector of the disease. Historically, the primary method of malaria control has been to spray indoor walls with DDT. It's an efficient way to kill the bugs, given their habit of resting on walls, and only tiny amounts are needed.

More importantly, studies show that mosquitoes are reluctant to enter a DDT-treated building, which means it offers a far cheaper alternative to prophylactic drugs or bed nets. Use of DDT in Sri Lanka cut malaria rates here from 3m cases a year in the 1940s to fewer than 50 in 1963.

Since then, environmental pressures against DDT have forced it to be abandoned, first in Western countries and then in most other parts of the world. Although it was obvious that it was the massive use of DDT in farming, not the small amounts used in public-health applications, that caused the environmental problems, the issue of scale was ignored by policymakers.

Aid agencies' failure to fund DDT was defended by studies that showed that Sri Lankan mosquitoes were developing resistance to DDT, an argument which ignores the chemical's main benefit. Treated houses repel mosquitoes better than any other insecticide yet tested but the WHO, adopting the anti-DDT environmentalist agenda, ignores it, instead advising the use of alternative insecticides.

The organisation spent the vast majority of its $980,000 Sri Lankan tsunami-related resources on bed nets (about $780,000), and about $100,000 on organophosphate insecticide spray, Malathion. Even this was not used in its most effective form of indoor spraying, which provides months of protection, but was instead used in clouds. Even the WHO admits that this is of limited use. It does, however, look good on television, and demonstrates something is being done.

The WHO is also supplying about $70,000 of old drugs, and pharmaceutical company Novartis has donated more than $40,000 worth of its new anti-malarial drug, Coartem. (The old drugs still just about work, although the oldest, chloroquine, is losing its efficacy here.)

WHO agents on the ground, along with other aid agency personnel, are doing the best they can, but they are hampered by an official policy that is harmful. Unfortunately, to speak out against it is to risk one's job. The cost can be measured in Sri Lankan lives lost.

Though Janaka Tillakeratne lost his café to the tsunami, he has kept his family safe and free from major disease. But he has no bed nets for them and would like his house to be sprayed to lower his children's risk of disease, but it's unlikely to happen.

As I left for the airport he smiled and told me to come back and watch some cricket here again. "Perhaps in a year when the pitch is repaired," he said. "And make sure you buy produce from my new shop," which he is already planning. I handed him my remaining supply of Coartem; it was the least I could do.

The tragedy of the tsunami is obvious and largely unavoidable. But malaria deaths could be significantly reduced if only health agencies would do the politically incorrect - but morally correct - thing and spray DDT and other long-term insecticides.

If this disaster doesn't persuade them to change, nothing will - except perhaps a major outbreak. It's no fun, I can tell you.

  • Roger Bate is a health economist with Africa Fighting Malaria and a fellow of the American Enterprise Institute and the Institute of Economic Affairs.