DDT is still very available in other parts of the world. It is and was a very effective insecticide that was developed in the first place as an accident and later studied as a anti-human agent that failed to kill humans, but was accidentally discovered to have excellent insecticidal properties. It was probably responsible for saving more lives in WW2 than any other action due to it being used extensively for lice control ( a major vector of typhus and other diseases that ravaged troops).
Our government has overreacted on many insecticides the most recent of which was the removal of chlorpyrifos (Dursban) from the public relm. (while chlorpyrifos is relatively non-toxic to mammals, it is an organophosphate (OP) that has been determined to be as a group dangerous to people. Other OPs are quite deadly, however it was removed simply because the chemistry is similar.
DDT should be available for use in certain conditions, just not the wholesale use that it saw in the 1940-70's
SAM