DDT will not eliminate malaria. True, it would likely reduce deaths by the disease by a good amount. However, it does do damage to the environment, esp if used poorly, as it was in the West for a couple of decades.
However, DDT is still used, but often without approval of the WHO, who monitors it’s use to prevent mosquito resistance:
wiki"Resistance has greatly reduced DDT’s effectiveness. WHO guidelines require that absence of resistance must be confirmed before using the chemical.[90] Resistance is largely due to agricultural use, in much greater quantities than required for disease prevention. According to one study that attempted to quantify the lives saved by banning agricultural use and thereby slowing the spread of resistance, “it can be estimated that at current rates each kilo of insecticide added to the environment will generate 105 new cases of malaria.”[21]
Resistance was noted early in spray campaigns. Paul Russell, a former head of the Allied Anti-Malaria campaign, observed in 1956 that “resistance has appeared [after] six or seven years.”[19] DDT has lost much of its effectiveness in Sri Lanka, Pakistan, Turkey and Central America, and it has largely been replaced by organophosphate or carbamate insecticides, e.g. malathion or bendiocarb.[91]
In many parts of India, DDT has also largely lost its effectiveness.[92] Agricultural uses were banned in 1989, and its anti-malarial use has been declining. Urban use has halted completely.[93] Nevertheless, DDT is still manufactured and used,[94] and one study had concluded that “DDT is still a viable insecticide in indoor residual spraying owing to its effectivity in well supervised spray operation and high excito-repellency factor.”[95]
Mind you, there’s no force stopping nations or NGOs from buying it and spraying it. Just that they often won;t get any finacnial support if they do so without WHO oversight. It’s about the $$.
wiki "It has also been alleged that donor governments and agencies have refused to fund DDT spraying, or made aid contingent upon not using DDT. According to a report in the British Medical Journal, use of DDT in Mozambique “was stopped several decades ago, because 80% of the country’s health budget came from donor funds, and donors refused to allow the use of DDT.”[116] Roger Bate asserts, “many countries have been coming under pressure from international health and environment agencies to give up DDT or face losing aid grants: Belize and Bolivia are on record admitting they gave in to pressure on this issue from [USAID].”[117]
The United States Agency for International Development (USAID) has been the focus of much criticism. While the agency is currently funding the use of DDT in some African countries,[118] in the past it did not. W… USAID’s Kent R. Hill states that the agency has been misrepresented: “USAID strongly supports spraying as a preventative measure for malaria and will support the use of DDT when it is scientifically sound and warranted.”[120] …The website further explains that in many cases alternative malaria control measures were judged to be more cost-effective that DDT spraying, and so were funded instead.[121]"
DDT,when used for human protection, concentrates in breast milk, generally considered a “bad thing”. Also, when it is approved for "limited use " in homes, it very often gets diverted to agri use, which is not good either.
It’s a complicated issue, with no easy answers.