Threats from mosquitoes are ever-present. There is no vaccine yet and the malaria parasite is constantly developing resistance to the few available recommended drugs. South Africa however, appears to have found a way out of the dilemma and claims to be on the path of eliminating the disease by turning to the use of DDT alongside other commodities for malaria control.
The current use of dichlorodiphenylt-richloroethane (DDT) in South Africa and other countries is a clear case of picking one's poison when all available options
Some will criticize the use of the chemical. But decision-makers also contend they are overwhelmed by the dilemma posed by the fact that even the trusted bed nets are facing difficulties as mosquitoes develop resistance to the insecticides used to treat them.
Having pulled no punches in the battle against the biggest killer of women and children, South Africa has exclaimed with confidence that “The country is well on its way to being a malaria-free country."
Africa's wealthiest and most developed country has set its sights on eliminating the disease by the year 2018.
The country's Health Minister, Dr Aaron Motsoaledi, said at the just ended pan-African malaria conference in Durban that South Africa has turned the tide on malaria, cutting mortality rates by 85 per cent over the last 12 years, and hopes to eliminate the disease soon.
Viewed against the success stories in Botswana, Cape Verde, Eritrea, Madagascar, Namibia, Rwanda, and Zambia where a 50% reduction in malaria cases and deaths have been reported, the fight against malaria is a good fight that has gotten even better.
But whereas most countries rely on the recommended control tools like bed nets, indoor residual spraying and artemisinin-based combination therapies (ACTs), South Africa has gone off the beaten track by including D DT to kill malaria-transmitting mosquitoes.
“Last year, only 70 people died from the mosquito-borne disease, compared to 460 deaths recorded in the year 2000. The number of people who caught malaria has come down to about a 10th of the cases recorded that same year,” Dr Motsoaledi said, quoting from a national report.
Medical experts and stakeholders at the Multilateral Initiative on Malaria (MIM) conference, which took place from 6th-11th October 2013, received the news with ambivalence, knowing the controversy surrounding the dreaded insecticide.
The chemical, which is sprayed inside houses, is linked to genital birth defects, infertility and cancer and is banned in many parts of the world.
South Africa joined a host of other countries to stop the use of DDT in 1996 only to reintroduce it in 2000 as part of a plan to curb a major malaria outbreak.
Following the ban of DDT in South Africa, malaria infections reportedly trebled in 1996, rising to 64,500 in 2000. The local health authorities decided to act fast.
"The mosquito problem was overcome by combining DDT and pyrethroids for malaria vector control in the three malaria-endemic provinces," said Motsoaledi. According to the South African malaria report, the insecticide has been used cautiously in recent years, "with targeted spraying only in high risk areas.”
Its safety has always been questioned, with local authorities maintaining that it is less expensive but more effective amid a spike in insecticide resistant vectors in
South Africa appears clearly to have chosen the option for rapid results when confronted with a decision to save lives, in what Dr Motsoaledi describes as a "well-thought out strategy that is practical, systematic and robustly implemented.”
DDT was used mainly in impoverished households in the North-Eastern Limpopo region, which borders Mozambique and part of the South-Eastern province of KwaZulu Natal, where malaria is endemic.
Prevention has seen cases drop to less than one per 1,000 people in affected districts, according to the report.
The report stated that some households refused to have their houses sprayed, saying the chemical left stains on walls, implying that it is not an appropriate technology. This is also seen as ignorance of the health effects among the teams spraying people's homes with the chemical.
University of Pretoria's professor Tiaan de Jager, a researcher of sustainable malaria control and pesticides and industrial pollutants, acknowledged the adverse genetic and hormonal risks linked with DDT, adding however that its efficacy cannot be discounted.
Prof De Jager believes that a combination of improved housing, sanitation and education should form part of the control strategies against the disease, instead of the reliance on DDT.“We are not saying that people should rather die than using DDT. However, we can't rely on DDT; we should also look at safer methods that can lead to elimination.”
Opinion remains divided on the use of DDT to fight malaria. The fact that it is being used in impoverished areas could lead some people to think that the lives of poor people are less regarded.
The countries that banned (DDT), say it will only be used as a last resort against disease-bearing mosquitoes. However, DDT is still a routine option in some African countries, mainly because of the rapid results it gives.
The DDT ban, which began in the US and other western countries, is now widespread because international development aid and funding has been tied to the prohibition of its use.
Third World countries are told that if they want foreign aid money, they need to stop using the most effective weapon against malaria. They are compelled by necessity to comply with this condition.
As a result, insect-borne diseases have returned to the tropics with a vengeance. By some estimates, the death toll in Africa alone from unnecessary malaria resulting from the restrictions on DDT has exceeded 100 million people.
Some commentators defend the use of DDT in situations like the one in South Africa where a sudden escalation demanded a swift intervention.
The routine use of DDT against malaria is generally deemed to be an exercise in toxic futility, especially when it is pursued at the expense of a superior and far more benign technology like the bed net.
Resistance to chemicals
Resistance to DDT was reported way back in 1946. It became known that in mosquitoes, regular exposure to DDT tended to produce resistance within four to seven years.
Stakeholders also noticed with dismay that the use of DDT faced problems in large, heavily infested areas with high human populations, poor housing and roads, and poor infrastructure. The reality is that in such conditions it will not be possible to eliminate the disease before the problem of resistance sets in.
This was deemed to have taken the wind out of the sails of the eradication campaigners. And so in1969, the campaign was abandoned. DDT resistance is reported to be widespread in Anopheles mosquito.
Till today, some followers of the DDT debate have expressed outrage at the biologist and nature writer Rachel Carson, who claimed in her publication 'Silent Spring', that there was a town whose people and wild life had been extinguished through the use of DDT as a
She said when animals ingest the fat-soluble DDT, the chemical tends to concentrate in their fat, instead of being excreted. As a result, when other animals or humans eat the tainted animal, they absorb the prey's DDT, increasing the concentration of DDT in the food chain.
DDT was described by Carson as having toxicity from long-term exposure that causes physiological abnormalities in humans and animals. There were other claims like, “DDT causes cancer in humans and endangered birds with imminent extinction.”
The panic raised by Carson's book deterred many countries from DDT-based anti-malaria programmes, with consequences estimated at millions of deaths around the globe.
Proponents of DDT argue that within the two decades that it was rolled out, DDT revented 500 million malarial deaths. They add that never before in history had a single chemical saved so many lives in such a short amount of time.
Again, they contend that, contrary to Carson's claims, several studies of breast cancer, lung cancer, testicular cancer, liver cancer and prostate cancer, failed to show significant evidence that exposure to DDT causes cancer. The purported threat of DDT to bird and wildlife was reportedly shown to be unfounded.
The race against malaria is one against time. Decisions have to be taken realistically. While arguments and counter-arguments are being fired like missiles, lives continue to be lost to a ruthless killer of pregnant women and children.
As researchers are working hard at improved technologies against malaria, the least communities can do is to make rational choices to stay alive today and remember also to ensure a healthier society for tomorrow.