Whenever I teach on the history of malaria, I talk about the different time periods when certain ideas were fashionable and implemented, and then disappeared, and sometimes came back much later.
Take the 'chloroquine era'. Discovered by Bayer scientists in the early 1930s and saved millions of lives around the globe, followed by resistance popping up in SE Asia and Colombia in the late 1950s. Resistance spreading to Africa in the late 1970s, and its use now largely reduced. End of the 'chloroquine era'.