比較不同去移生介入政策對醫院內金黃色葡萄球菌感染率及Mupirocin抗藥性的影響: 數理模式研究

Effect of Different Decolonization Policies on Nosocomial Staphylococcus aureus Infection Rate and Mupirocin Resistance: A Modeling Study

林政由(Cheng-Yu Lin)

指導教授 ： 方啟泰

國立臺灣大學/公共衛生學院/流行病學與預防醫學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.10816

摘要

背景：金黃色葡萄球菌 (Staphylococcus aureus) 是院內感染中常見的致病菌。即使使用抗生素治療，一旦感染就會造成額外的死亡風險、住院日數、及醫療花費。使用含Mupirocin成分的鼻內軟膏對帶菌者做去移生治療已被證實可降低病人後續的感染風險，但去移生介入政策最大的顧慮在於：Mupirocin抗藥性S. aureus比例上升的問題。然而，不同去移生政策對醫院內S. aureus感染率及S. aureus Mupirocin抗藥性的影響尚未被釐清。

方法：這是一個數理模式研究，我們先建構一個考慮Mupirocin抗藥性的院內傳染動態模型，使不同mupirocin抗藥性的S. aureus可以在醫院內經由病人及醫護人員傳播。然後模擬去移生介入政策對S. aureus感染率及Mupirocin抗藥性的影響，並利用實證研究的資料來校正模型，最後評估不同介入政策對降低S. aureus感染率和提高Mupirocin抗藥性S. aureus比例的影響。

結果：相較於未介入期，Targeted decolonization與Universal decolonization皆能降低28.1%及29.4%的S. aureus感染率，但Universal decolonization會伴隨較大的Mupirocin抗藥性比例上升 (3.0% vs. 1.4%)。相較於Targeted decolonization，只做篩檢隔離對降低S. aureus感染率的效果大幅地降低 (10.4% vs. 28.1%)。同時推動Targeted decolonization搭配最佳的洗手運動及隔離照護能帶來更顯著的降低S. aureus感染率效果 (67.6% vs. 19.3%)。

結論：Targeted decolonization是一個能有效降低S. aureus感染率的介入政策，並且伴隨著較小的Mupirocin抗藥性比例上升。若能同時推動Targeted decolonization和最佳的洗手運動及隔離照護，將有最好的介入效果。

關鍵字

金黃色葡萄球菌 ； 院內感染 ； Mupirocin抗藥性 ； 感染控制 ； 去移生 ； 篩檢 ； 隔離 ； 數理模式

並列摘要

Background: Staphylococcus aureus is a leading cause of life-threatening nosocomial infection. Even with antibiotics treatment, nosocomial S. aureus infections are associated with an excess mortality, medical cost and hospital stay. Decolonization with mupirocin can effectively reduce infection rate and negative consequences. The major concern for nationwide decolonization policy is the increase of mupirocin-resistant S. aureus. However, the impact of different nationwide policies on S. aureus infection rate and mupirocin resistance within hospitals has not yet been evaluated.

Methods: This is a mathematical modeling study. We first construct a dynamic model of nosocomial S. aureus infection in which mupirocin-susceptible and mupirocin-resistant S. aureus can be transmitted between patients and healthcare workers, then simulate the effect of nationwide decolonization policies on S. aureus infections and mupirocin resistance. Model was calibrated to simulate real world scenario. We compared the impact of different decolonization polices on the reduction of S. aureus infections and increase of mupirocin-resistant S. aureus in hospitals.

Results: Compared with baseline situation, 90% coverage rate of both targeted and universal decolonization decreased S. aureus infection rate (28.1% 29.4%), but universal decolonization is associated with larger increase in mupirocin resistance rate (3.0% vs 1.4%). The efficacy of screening and isolation alone on S. aureus infection rate is much less than targeted decolonization (10.4% vs. 28.1%). A 70% coverage rate of targeted decolonization with optimal handwashing and cohorting will lead to a markedly decrease in S. aureus infection rate when compared with targeted decolonization alone (67.6% vs 19.3%).

Conclusions: Our results support the targeted decolonization as an effective policy to reduce nosocomial S. aureus infection rate with a minimal increase in mupirocin resistance rate, especially when combined with handwashing campaign and stricter cohorting.

並列關鍵字

Staphylococcus aureus ； hospital-acquired infection ； mupirocin resistance ； infection control ； decolonization ； screening ； isolation ； mathematical modelling

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