DDT a potent weapon against malaria

Kelvin Kemm | 20 May 2023
Engineering News
World Malaria Day is celebrated in April each year. As this important day slips past unnoticed by most, it is worth pondering the disease for a while.

I have had an interest in malaria for many years and, a few years ago, I was invited to write a chapter in a book published in London on Third World health. My chapter was on malaria and the wonder chemical DDT. I was amazed at what I found out when I really looked into the topic. DDT is not at all harmful, as so many activists have claimed.

South Africa is currently a world leader in malaria control and has achieved great success, particularly since reintroducing the use of DDT a number of years ago.

Malaria is both preventable and curable, and I am sure, had the world invested as much effort into wiping out malaria as has been put into HIV/Aids, we would prob- ably have no more malaria today.

Malaria used to be prevalent in Europe, England and the US, but not anymore. In those places, it has been wiped out. Interestingly, in Shakespeare's works, he mentions malaria eight times.

What is worrying is that, for the last decade, the number of recorded malaria cases in Limpopo province has averaged 413 over the Christmas period but, during this past Christmas, they rose to 488, which is a statistically significant rise. Some of this rise can possibly be attributed to the weather, and some proportion of it to what is known as 'taxi' malaria and 'suitcase' malaria. I have also found out about 'pot plant' malaria. Improved travel between countries plays a role. Luckily for South Africa, our only malarial area is in the far north-east of the country, but people cross over from neighbouring countries and bring malaria-carrying mosquitoes in their baggage and in taxis.

I know people have gone down with malaria in Pretoria, and they could prove that they never left the city environs for months. I found out about pot plant malaria. Pot plants are brought in to local nurseries from malarial areas with the mosquitoes in the pot plants. People then buy them and take them directly into their houses.

South Africa has had great success in recent years in controlling malaria and has also entered into agreements with neighbouring States. The most successful cross-border malaria control programme has been the Lubombo spatial development initiative. This is a trilateral arrangement between South Africa, Mozambique and Swaziland. Since its inception in 1998, the initiative has reduced the malaria incidence on the Swaziland border from more than 25% to less than 2%. In 1999, in Maputo, the malaria incidence was 60%, but is now below 5%.

In the US, a number of years ago, a woman, the late Rachel Carson, wrote a book called Silent Spring, which condemned DDT as being harmful to humans and to animals, particularly birds. This book was largely responsible for the large-scale banning of DDT all over the world. The book was wrong. In later life, Carson admitted that she had written it more as a novel than as a true scientific work, but the damage had been done. Millions of people had died as a result.

There is now no evidence that would stand scientific scrutiny that shows that DDT is harmful to humans. During talks that I have given in public on the topic, I have twice met ladies in their 80s and 90s who told me that their mothers had given them a teaspoonful of DDT each week for years to ward off polio. As it happens, it does not do anything to ward off polio but, 50-plus years ago, when mothers were really worried about polio and, desperate for some affective medi- cine which did not exist at the time, they tried DDT because it had been so successful in the fight against malaria.

When malaria was wiped out in Europe and the US in the mid 1970s, DDT was banned because of the claims of Carson et al. They made African countries ban it too and the death rate in Africa soared. Meanwhile, the International Agency for Research on Cancer classifies DDT as a 'possible carcinogen', which places it in the same category as beer, coffee and peanut butter. I am not aware of a single case in the world of any person getting cancer from DDT, and am certainly not aware of any deaths.

After the Second World War, all the inmates of all the Nazi concentration camps were infected with body lice. They were all repeatedly sprayed with DDT when Allied troops liberated them. Both Tokyo and Naples also had 100% body lice infection of the population when Allied troops arrived. They too were sprayed. Over the years, no adverse health effects from DDT were ever detected in any of these populations, even though they were monitored for many years.

South Africa needs to keep up the antimalaria drive and to work with neighbouring States. A friend of mine died of malaria, which was totally unnecessary. Continued resolve is needed to get rid of the menace totally.