The three steps taken by the French to solve the problem of plague in Vietnam are given below
(i) A rat hunt was started in 1902. The French authority hired Vietnamese workers and paid them for each rat they caught.
(ii) Bounty programme was started by the colonisers. Those who did the dirty work of entering sewers could negotiate a higher bounty if they come together. The bounty was paid when a tail was given as a proof that a rat had been killed.
(iii) The French ordered the clearing of the large sewers on a regular basis as these had become an ideal and protected breeding ground for rats.