A gross exageration and a bit of forgetfulness about medical science. Draining swamps and spraying mosquitoes WAS led by medical science.
I'm not sure traumatic injuries have been reduced at all, however, I am certain that treating them has improved to the point that almost no one dies from a compound fracture now.
Sanitation also came out of the medical sciences.
Not arguing with your contention but the draining of swamps was done before it was known why that reduced such as malaria.