He may have intestinal parasites: tapeworm or ascarid hookworms. Hookworms are far worse, if too many they can block the bowel. Antihelmintic medicines can get rid of these effectively; they could be traditional or modern medications.
3 stages. Must get it cured in the first or second stage. Third stage involves madness & death.
Second stage involves chancres (weeping sores) on genitals.
First stage involves spots on torso.
Must be detected in first stages.
If worried go get tested.
I wonder whether they have looked at the impact of introducing a voracious predator. It will eats lots. A beneficial income is not guaranteed. The case of the introduction of Nile perch to African lakes would have been instructive.
Simplistic solutions seldom work as planned.