健康照護者水痘篩檢調查與成本效益分析比較──北部某區域教學醫院之經驗

Seroprevalence and Cost Analysis of Varicella Zoster Virus Infection among Healthcare Workers in a Regional Teaching Hospital

調查資料顯示台灣10～20%成年人對水痘血清抗體檢測結果為陰性。健康照護者由於職業特性，容易暴露在水痘病毒環境中，增加了感染風險。此篇研究採兩階段進行篩檢測試，第一階段先利用問卷方式，對全院員工（746人）水痘病史展開初步調查，第二階段再針對自述病史為不確定及確定未得過水痘者（268人），進行血清抗體篩檢。篩檢為陰性者有25人，抗體陰性率為9.3%（25／268）。經檢驗發現，員工水痘病史的陰性預測值僅19.5%（8／41），而參與血清抗體篩檢的人員有高達90.7%（243／268）其實已有水痘抗體，自己卻不自知。透過水痘血清抗體篩檢，除了可讓員工對自己的水痘病史有確切了解外，抗體為陰性的員工，則由醫院進行資料庫建檔管理，並提供水痘疫苗優惠方案鼓勵員工施打，已降低臨床照護時因暴露而遭受感染的風險。自研究結束，後續追蹤近五年來調查，共有7位員工感染水痘，進一步精算，若健康照護人員施打水痘疫苗，期直接成本（醫療費用）平均每人可節省15,328元。同時，醫院可節省間接成本達平均每位員工約6,825元的額外薪資支出。因單位人力不足，導致縮床、關病房等無形成本則是無法估算的。本研究也發現，針對水痘血清抗體篩檢陰性者再施打疫苗之總費用及平均每人費用都比全部人直接施打疫苗之費用低（意即總費用差可達418,750元，平均每人費用差可達1,562.5元），較具成本效益。期望藉由此篇現況分析與成本效益比較，能讓醫院與衛生單位在未來制定水痘疫苗相關政策上，提供一個參考依據。

Recent epidemiological studies have shown that 10-20% of adults in Taiwan are susceptible to varicella zoster virus (VZV) infection. Health care workers (HCW) in particular are vulnerable to hospital-acquired VZV infection. We used a questionnaire to investigate the VZV status of HCWs in a regional teaching hospital. VZV immunoglobulin G (IgG) status was determined for HCWs who had no history or an uncertain history of VZV infection. Among the 268 HCWs evaluated, only 9.3% were seronegative. The negative predictive value for the history of varicella was 19.5%. The majority (90.7%) of HCWs with a negative or uncertain history were seropositive. “VZV serological status of HCWs should be determined. Vaccination for seronegative HCWs is recommended to prevent hospital-acquired VZV cross-infection.” According to a recent cost analysis of varicella vaccination, promoting a VZV vaccination program could save a hospital 30,840 Taiwan dollars. Based on our evaluation, it would be cost-effective to administer the VZV vaccination to seronegative HCWs after conducting a serum antibody-screening program.