The website Al-Islam.org has the following hadith (This link will direct you to the narration on the website):
Muhammad b. Ja’far al-Bursi narrated from Muhammad b. Yahya al-Armani from Muhammad b. Sinan from al-Mufaddal b. ‘Umar al-Ju’fi from Abu ‘Abd Allah al-Sadiq, peace be upon him, from his forefathers from Amir al-Mu’minin, peace be upon him, that he said: ‘The Messenger of Allah, blessings on him and his family, said: “Beware of eating ganglia (al-ghadad), for it stirs up leprosy.”’ He said: “The Jews were restored to health because of their avoiding the eating of ganglia.” He said: “When you see those afflicted with leprosy, ask your Lord for good health and do not be unmindful of Him.”
I haven't found any sources apart from the one above which state any connection between ganglia and leprosy.
Are there any additional accounts or sources (scientific and otherwise) which confirm that ganglia can cause leprosy or at least state that they are inter-connected?
EDIT:
Thanks to Jan Doggen, I know that al-ghadad refers to endocrine glands. Is there any evidence to suggest that eating the endocrine glands of animals can cause leprosy? Additionally, is there evidence to back hdhondt's claim that leprosy can only be caused by the presence of a certain bacterium in the animal?