護理師照護一位艱難梭菌（C. difficile）感染的病人。為預防傳播給其他病人，最重要的是哪項措施？

艱難梭菌（Clostridium difficile, C. diff）是一種革蘭氏陽性厭氧菌，其產生的芽孢（spores）對環境具有高度抵抗力，不易被酒精或一般清潔劑殺死。C. diff 感染常見於長期使用抗生素的病人，因抗生素破壞了腸道正常菌叢，使其過度生長，產生毒素引起腹瀉、腹痛等症狀。 預防 C. diff 傳播的核心在於有效清除芽孢。芽孢對酒精消毒劑不敏感，因此使用酒精搓手液（Alcohol-based hand sanitizer）無法有效殺滅芽孢。正確的預防措施是使用肥皂和水（Soap and water）進行徹底的洗手，透過機械性摩擦和沖洗來去除芽孢。 選項 A（使用肥皂和水洗手）是預防 C. diff 傳播最重要且最有效的措施。選項 B（使用酒精搓手液）無效。選項 D（佩戴 N95 口罩）和 C（維持負壓隔離室）是針對空氣傳播疾病（如肺結核 Tuberculosis, TB）的標準防護措施，對於透過接觸傳播的 C. diff 感染並非首要或必要的預防手段。

Clostridium difficile (C. diff) is a gram-positive anaerobic bacterium whose spores are highly resistant to environmental factors and are not easily killed by alcohol or routine cleansers. C. diff infection is commonly seen in clients on long-term antibiotic therapy, as antibiotics disrupt normal gut flora and allow C. diff to overgrow and produce toxins, causing diarrhea, abdominal pain, and other symptoms. The core of preventing C. diff transmission is the effective removal of spores. Spores are not susceptible to alcohol-based disinfectants, so alcohol-based hand sanitizer cannot effectively kill them. The correct preventive measure is to use soap and water for thorough hand washing, removing spores via mechanical friction and rinsing. Option A (washing with soap and water) is the most important and effective measure for preventing C. diff transmission. Option B (alcohol-based hand sanitizer) is ineffective. Options C (wearing an N95 respirator) and C (negative-pressure room) are standard precautions for airborne diseases such as tuberculosis (TB) and are neither the primary nor a necessary preventive measure for contact-transmitted C. diff.