Fresh round of lobbying for return of DDT in fight against malaria
Originally Published: February 12, 2011
For almost five centuries, man has been at war with a small parasite that has morphed into a Grim Reaper. But the distribution of victims is skewed as more than 80 per cent of deaths caused by the malaria parasite are recorded in Africa.
In Kenya, the World Health Organisation (WHO) estimates that about 10 million cases of malaria are reported annually, most of them in children under five.
But as busy researchers tune their microscopes, philanthropists keep donating, and doctors keep administering doses, there is growing concern that world health experts may have abandoned the most successful tool there was to eradicate the disease three decades ago.
One African nation has taken a bold step to, in a sense, defy the common wisdom and make a significant leap forward in reducing malaria deaths.
Through a public-private partnership, Ghana has re-introduced the use of indoor residual spraying of DDT to what experts say are promising results.
However, only time will tell whether other African nations should follow suit.
In 1944, governments the world over thought they had found the magic bullet in a chemical known as dichloro diphenyl trichloroethane – better known as DDT.
The United States lost thousands of troops to malaria during the Second World War, and the government, led by President Franklin Roosevelt, was actively seeking a permanent solution to this: the “magic powder,” as DDT came to be known.
The Rockefeller Foundation agreed to fund a five-year malaria eradication programme through the use of DDT. More than one million American homes were sprayed with DDT as were hundreds of thousands of acres of farmland in the initial eradication phases. By 1951, the US was a malaria-free country.
WHO records show that the malaria prevalence rates of Sri Lanka, Greece and Italy fell markedly during the years DDT spray was used to eradicate the mosquitoes that host the parasite that causes malaria.
For instance, the South Asian nations managed to cut malaria cases from three million in 1946 to fewer than 8,000 in 1951. In light of these numbers, it seemed like a good idea to take the war on malaria global.
“At that time, WHO had just been formed, and it needed a cause to justify its existence and funding. It approached various bodies to fund its global war,” Dr Evelyne Nelima, a pharmacist and malaria researcher, said.
The funding was approved, and WHO concentrated its efforts mostly in Asia and the Pacific island nations. But by 1965, the goodwill necessary for a global approach towards malaria eradication was running low. A host of issues were coming to light. Apparently, DDT came with its own problems.
One of the issues invoked by groups like the UN Food and Agriculture Organisation (FAO) as the most urgent crisis facing humanity was overpopulation. In its first food security survey, FAO argued that the rapid increase in population came about, at least in part, due to the decreased mortality rate from diseases like malaria.
“It was an opinion that did little to mention that by this time malaria had only been eradicated in a handful of nations through the sustained and primary use of DDT and other methods. Given time, the same could be replicated in other areas of the world, particularly in Africa,” Dr Nelima said.
For many Western donor governments, overpopulation was proving to be a much bigger burden than malaria. At the 1969 World Health Assembly, WHO urged governments to stop trying to eradicate malaria and instead try to live with it.
“Soon after, it (DDT) was banned for use in agriculture,” said Richard Trent, a malaria researcher, author and director of Africa Against Malaria.
The ban had a knock-on effect. By the early 1970s, the price of DDT was rising and World Health Assembly records show that malarial countries were requesting assistance from WHO to procure the insecticide.
“Supplies were down, and prices were up. By the mid 1980s, attention and funding for malaria control had shifted. It was left to individual governments to develop their own strategies, not forgetting some of these countries were barely two decades old,” Mr Trent said.
It is estimated that during the DDT years, malaria eradication cost an average of US$1 billion. In 2009, global control programmes are estimated to have cost US$9 billion. Translation: malaria is big money business.
“I believe we need more, not less money, invested in controlling infectious diseases of all kinds, including malaria. Given the devastating cost of malaria in human and economic terms, I think it warrants all the attention we give it,” said Christian Loucq, Director of the PATH Malaria Vaccine Initiative.
PATH says the vaccine has been in development for the past quarter century. Conservative estimates indicate a workable vaccine could be ready in the next three to five years.
But there are those who believe that global responses to the disease have always been selective and that, had the focus been maintained on a wider segment of the world, the toll the disease has taken would not be as high as it is. It is on this issue that pro-DDT advocates find their voice.
“If there hadn’t been the stigma against DDT use, and if the Western world and United Nations agencies had built and sustained malaria control programmes in the 1950s and 1960s, we probably would have a much lower incidence of the disease,” Mr Trent said.
An attempt to even out the discrepancies was made in 2006 when WHO lifted the ban on DDT usage. After the lifting of the ban, Uganda, a country in which 11 million people suffer from the disease each year, reintroduced light indoor use of DDT through the support of the US President’s Malaria Initiative (PMI).
Just a few months after the spraying programme kicked off, various European Union representatives sent out a warning that any trace, no matter how minute, of DDT on any produce grown for export to the Euro zone, would lead to a ban on Uganda produce.
Subsequently, tests were conducted on coffee exports. Traces of DDT were found in them, and the Ugandan government was forced to abandon its indoor spraying programme.
After years of research and drug development worth billions of dollars, the statistics are still worrying.
Data from Kenya’s Division of Malaria Control puts malaria as the leading cause of morbidity and mortality, with over 26 million people being vulnerable.
In spite of the problems that the ban on DDT caused as well as drug and staff shortages in Kenya, the government believes it is doing its best. And its best defence is in a policy paper: The Kenya National Malaria Strategy (KNMS).
“Its goal is to reduce by 30 per cent all morbidity and mortality caused by malaria. We hope to maintain this reduction through to 2017,” said Dr Elizabeth Juma, head of the Malaria Control Division in the ministry of Public Health and Sanitation.
Referring to the paper, researcher Dr Nelima said: “The policies are ever so brilliant, but what happens on the ground is from another script.”
Funding shortfalls to cover the country’s essential stocks still occur.
“For a buffer, you need nine months of stock at a cost of about half a billion shillings. It’s critical that Kenya gets buffer stocks but they aren’t the solution,” Dr Juma said.
The Sh40 billion allocated in the 2010/2011 budget is not enough to independently purchase the drugs.
According to KEMRI Wellcome Trust, for years substantial amount of funding for malaria research has been spent on monotherapies (chloroquine, sulfadoxine-pyrimethamine).
These drugs are often ineffective in Africa because of parasite resistance; artemisinin-based combination therapy known as ACT is often more successful.
Although malaria continues to exact a toll on populations, hope persists that the solution will eventually be found.