SARS院內感染中人員之感染狀況及其對醫院感染管控之啟示

Abstract

背景:由台灣一家遭受SARS嚴重院內感染的醫院人員受感染的情形，由醫院管理的角度，整理歸納出其與醫院環境、個人特性等之相關性，從而提供醫院內感染控制及管理之方針。 材料及方法：收集該院感染事件所有相關人員之身份、通報染SARS之罹病狀況及存歿等資料，分析所有相關人員之身份與通報染SARS之罹病狀況及存歿之相關性。以及收集醫院工作同仁之年齡、性別、工作樓層、職業別、工作單位等資料；分析醫院工作同仁被通報染SARS與健康同仁各變項之分佈狀況及相關性。另收集被通報染SARS同仁之通報日期、病毒抗原及抗體檢查結果及臨床判定等資料；分析被通報染SARS同仁各變項之間分佈狀況及相關性。另外對777位健康員工作SARS抗體之篩檢，以研究此族群之抗體陽性率，並對抗體陽性之同仁作半年及一年後之抗體追蹤。 結果：在該院感染事件所有相關人員1539人中，醫院員工976人（63.4％），外包人員38人（2.5％），病患和家屬366人（23.8％），以及外部支援人員159人（10.3％）。所有相關人員中，共有108人被通報，其中75人被判定為SARS可能病例，33人被判定為疑似病例，可能病例佔在院隔離人數之4.9﹪；共計25人死亡，包括被判定為SARS可能病例者24人死亡（可能病例個案死亡率32％），而被判為疑似病患者1人死亡。 在醫院工作同仁共1014人中，有62位被通報染SARS，平均年齡為36±9.9歲。以急診及B8病房發病人數最多，職業別以護理人員為最多；被通報染病與工作樓層、職業別、工作單位有顯著相關，與年齡及性別無關。 62位被通報染SARS同仁中，扣除抗體資料不全者後共59例，其中男性9位，女性50位；8人死亡；42人判定為可能病例（4.1%），17人（2.0%）判定為疑似病例。42位可能病例中，抗原陽性者有21位（50％），抗體陽性者有32位（76.2％）；疑似病例17位中，抗原陽性者0位，抗體陽性者12位（70.6％）。抗原與職業別及通報日期具顯著相關性；抗體與性別具顯著相關性；臨床判定與職業別及通報日期具顯著相關性；存歿與工作單位及通報日期具顯著相關。抗原與存歿及臨床判定有相關性，但與抗體反應無相關性。抗體與存活有相關性，而與臨床判定無相關性。存歿與臨床判定之間不具相關性。 32位抗體陽性，而接受完整追蹤之同仁，半年後之抗體陽性率為100％，一年後之陽性率為69.4％。健康的員工中有4位抗體反應為陽性。 結論：SARS造成該院內健康照護者及病患高比率的罹病及死亡率。以抗原、抗體、存歿、臨床判定之間的不一致相關性而言，SARS之診斷仍需依靠臨床及實驗室數據的綜合判斷。各種個人特性及工作環境因素中，工作地點及通報日期，較明顯影響罹病。故應改善醫院的空間規劃及加強人員的教育訓練與管制，並在感染發生時，快速的展開疫調、隔離、個人防護等措施。病毒抗原PCR檢查之陽性率偏低，需作至少兩套以減少偽陰性。抗體檢查具高度靈敏性及特異性，適合作流行病學之調查。抗體會衰減消失。無症狀之醫院工作同仁可有陽性抗體反應。

Background. SARS was a severe infectious disease that caused marked damage worldwide. SARS also challenged the infection control system and hospital management. From the infectious condition of the persons in a hospital that was attacked by SARS, we analyzed the role of personal characteristics and environment on the infection control managements. Material and methods. The data about all the personns that were involved in the SARS infection of the hospital was collected, including the age, sex, working unit, working floor, and occupation. The result of antigen(PCR) and antibody studies, the mortality, the clinical classification of probable or suspect cases, and the time of being reported as infected, were collected from health care workers (HCWs) who were infected by SARS. The distribution and correlation among variables of the infected HCWs were analyzed. Seven hundred and seventy-seven asymptomatic HCWs received antibody survey about one month after the onset of the event to study the epidemiological of the nosocomial infection. Thirty-two HCWs received 3 times of antibody surveys follow up within one year. Result. There were 1539 persons involved in the SARS nosocomial infection, including 976 hospital employees (63.4%), 38 outsourcing employees (2.5%), 366 patients and their family members (23.8%), 159 members of rescue team from other institutes (10.3%). Totally 108 persons were reported as been infected, 75 (4.9% of all involved persons) were classified as probable and 33 were classified as suspect SARS patients. Twenty-four probable cases expired (case fatality rate 32%). Sixty-two colleagues were reported as infected among 1014 HCWs. Persons in ward B8 and emergency room as well as being nurses had the largest number of HCW being reported as the SARS victim. Reported cases were significantly correlated to working floor, occupation and working unit, and not correlated to age and sex. Fifty-nine colleagues that were reported and had complete data were further analyzed. There were 42 probable and 17 suspect cases. Among the 42 probable cases, 21 had positive PCR, 32 had positive antibody. Among the 17 suspect cases, none had positive PCR, 12 had positive antibody. Thirty-two colleagues who had initially positive antibody received followed up at 6 months interval. The result revealed a 100% of positive rate at 6 months, and a 69.4% positive rate at 12 months. There were 4 positive antibody results in the asymptomatic HCWs. Conclusion: SARS caused a high infection rate and mortality at the study hospital. Working unit and occupation significantly affected the infection rate. The environment control and the education about personal protection, as well as the improvement of ventilation system, are important measures to reduce the severity and the extend of nosocomial viral infection.