目的: 抗甲氧青黴素金黃色葡萄球菌(Methicillin-resistant Staphyloccus aureus、MRSA)是我國最重要的院內感染菌種之一，眾多醫護人員暴露在遭受感染的風險中。本文報告兩例醫院工作人員懷疑因工作而感染MRSA所致皮膚膿瘍，尋求職業病診斷的過程、方法、與結果，並加以剖析。

方法: 利用兩位員工的工作日誌，比對是否曾在合理的潛伏期內照顧過MRSA陽性患者，利用主成分分析、複合相關指數、以及比對SCCmec基因特有的蛋白質表現型，進行菌種鑑別。

結果: 兩位員工其中一位未曾照顧MRSA陽性患者，另一位員工指認出一位患者，但主成分分析、複合相關指數、與SCCmec基因特有蛋白質比對均顯示與指標患者的MRSA菌種不同，可以排除職業性感染。兩位員工均未得到職業病診斷書，無法進行公傷與勞工保險職業病給付的申請。

結論: MRSA是醫療保健服務業一項重要、潛在的職業風險，值得加以重視，但是如何對疑似個案進行職業病診斷存在困難。表現型分析可以排除職業性起因，但不足以達到歸因的準確性，可能需要合併發展基因型分析的認定參考指引，以保障醫護人員的權益。

Objective: Methicillin-resistant Staphyloccus aureus (MRSA) is one of the most important nosocomial infectious agents in Taiwan, to which many health-care personnel are exposed at work. This article reports two hospital employees suffering from MRSA skin infection and seeking the diagnosis of occupational disease. The scheme, methods and results of diagnostic process are discussed 。

Materials and Methods: Cross-comparing the worklogs of employees and MRSA-positive patient list to search for index cases, followed by principle component analysis, correlaton index matrix and SCCmec protein phenotyping with an aim to identifying potential match.

Results: One of the employee did not attend to MRSA patients during his disease incubation period. The other one identified an index patient, but principle component analysis, correlation index matrix and SCCmec protein phenotyping indicated that their MRSA strains did not match, thus excluding an occupational origin. Neither of them could proceed to the filing of occupational disease-related benefits.

Conclusion: MRSA is an important work-related risk factor for health-care personnel, but how to diagnose and recognize it as occupational disease poses considerable difficulty. Phenotyping serves to exclude work-relatedness, but more precise genotyping is needed to aid the diagnostic process.