阿尔茨海默氏 is the surname Alzheimer plus
氏 (shì, family/lineage marker), the Chinese convention for naming diseases after a person — the same way
氏 attaches to
帕金森氏 (Parkinson's) or
唐氏 (Down). Almost never appears alone; it pairs with
症 zhèng or
病 bìng to form the disease name. Mainland medical writing increasingly drops the
氏:
阿尔茨海默病 is now standard.