Successful eradication in Florida and Italy was based on aggressive source control (stagnant water), control of re-importation, and use of insecticides (including DDT) for outbreak control.
Airborne spraying of more targeted larvicides continues to be used in Florida and other places.
Malaria rates in rural areas of Africa are much higher than urban areas so urbanisation also plays a role.
It was used in Africa, at least in 2016.
http://chm.pops.int/Implementation/DDT/DDTMeetings/DDTEG6201...
> Why don’t we use DDT today?
You mean for agriculture? Because using DDT for disease vector control was never internationally banned (only banned at the national level).
It's banned in agriculture because it kills stuff other than the mosquitoes. In particular, its use is restricted by the "Stockholm Convention on Persistent Organic Pollutants". Persistent Organic Pollutants are pretty much as bad as they sound, and DDT is one.
http://www.rachelcarson.org/SilentSpring.aspx
Despite the environmental damage of DDT the Africans wanted to wipe out malaria first but were not able to purchase it in the quantities needed.
As late as 2004 leading newspapers editorialized that eradicating malaria in Africa outweighed the environmental damage
https://www.nytimes.com/2004/04/11/magazine/what-the-world-n...
> Carson has been targeted by some organizations opposed to the environmental movement, including Roger Bate of the pro-DDT advocacy group Africa Fighting Malaria and the libertarian think tank Competitive Enterprise Institute; these sources oppose restrictions on DDT, attribute large numbers of deaths to such restrictions, and argue that Carson was responsible for them. These arguments have been dismissed as "outrageous" by former WHO scientist Socrates Litsios. May Berenbaum, University of Illinois entomologist, says, "to blame environmentalists who oppose DDT for more deaths than Hitler is worse than irresponsible." Investigative journalist Adam Sarvana and others characterize this notion as a "myth" promoted principally by Roger Bate of the pro-DDT advocacy group Africa Fighting Malaria (AFM).
This doesn't make sense. Eradicating malaria in Africa is beneficial to the human species. Environmental damage applies to all other species. I don't understand how one could "outweigh" the other. They are just two different objectives.
We’re not (yet) beings of pure thought who can exist independent of our environment, so the damage to the environment does have to be counted before we decide if something is net-positive.
https://m.youtube.com/watch?v=gtcXXbuR244
> DDT was less effective in tropical regions due to the continuous life cycle of mosquitoes and poor infrastructure. It was not applied at all in sub-Saharan Africa due to these perceived difficulties.
https://en.m.wikipedia.org/wiki/DDT#Use_in_the_1940s_and_195...
See "DDT":