比較Targeted與Universal去移生介入政策對全國抗藥性金黃色葡萄球菌感染率及Mupirocin抗藥性的長期影響: 數理模式研究

Abstract

背景：抗藥性金黃色葡萄球菌 (Methicillin-resistant Staphylococcus aureus, MRSA) 是院內感染重要致病菌。即使以抗生素治療，一旦感染就會造成額外的死亡風險、不可逆呼吸器依賴及長期洗腎、以及額外住院花費等。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可能導致Mupirocin抗藥性比例上升。然而，不同去移生政策對醫院內及社區中MRSA感染率及MRSA Mupirocin抗藥性的長期影響尚未被釐清。 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MRSA可以在醫院內經由病人及醫護人員傳播。再建構一個社區的傳染動態模型，使MRSA可以在社區中進行傳播，並連結醫院及社區，模擬MRSA在不同醫院間及社區中傳播的動態。然後模擬去移生介入政策對MRSA感染率及Mupirocin抗藥性的影響，並利用台大醫院感染率變化趨勢的資料及台灣2010-2014年MRSA盛行率實證研究來校正模型參數，最後評估不同介入政策對降低MRSA感染率和提高Mupirocin抗藥性MRSA比例的影響。 結果：相較於未介入情境，Targeted decolonization與Universal decolonization皆能有效降低MRSA感染率 (10年後降低64.2% vs. 61.5%)，但Universal decolonization會伴隨較大的Mupirocin抗藥性比例上升 (10年後為4.91倍)，且隨著時間增加，兩者抗藥性比例的差異愈大 (50年後為46.48倍)。相較於僅持續推動洗手運動，洗手運動加上Targeted decolonization可進一步降低64.2%-71.4% MRSA感染率，在十年內預防46.5%-47.6% MRSA感染病例，並避免45.9%-47.2%的MRSA相關死亡。 結論：Targeted decolonization是一個能有效降低MRSA感染率的介入政策，並且伴隨著較小的Mupirocin抗藥性比例上升。在目前洗手運動基礎上，進一步實施Targeted decolonization可預防將近一半的MRSA 感染及死亡案例。

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading cause of nosocomial infections. Even with antibiotics treatment, nosocomial MRSA infections are still associated with excess mortality, morbidity, and extra cost of medical expenditure. Mupirocin-based decolonization regimens effectively reduce MRSA infection rate and related mortality. However, the major concern of MRSA decolonization is emergence of mupirocin-resistance in MRSA. We aim to evaluate the long-term effect of different decolonization strategies on both mupirocin resistance and MRSA infection rate, using a dynamic model fit to Taiwan national data. Methods: We constructed a deterministic model that simulates mupirocin-sensitive MRSA and mupirocin-resistant MRSA strains transmitted between patients and health-care workers within hospitals, as well as between discharged patients and community residents. We fit the model to the trend of 1997-2016 MRSA infection rate at National Taiwan University Hospital (NTUH) and 2010-2014 MRSA prevalence survey in Taiwan. We compared the impact of different national decolonization polices on the reduction of MRSA infection rate and increase of mupirocin-resistant MRSA in hospitals and community. Findings: Compared to baseline scenario (no intervention), both targeted and universal decolonization reduce nosocomial MRSA infection rates (64·2% and 61·5% after 10 years, respectively). However, universal decolonization causes significantly higher mupirocin resistance (4·91 times after 10 years), and the difference increases with time (46·48 times after 50 years). Sensitivity analyses show that the above-stated findings are robust across a wide range of parameter values. Compared to no intervention scenario (continuing hand hygiene campaign, without decolonization), implementation of targeted decolonization over the next 10 years would reduce nosocomial MRSA infection rate by 64·2%-71·4%, prevent 46·5%-47·6% cases of MRSA infections, and avert 45·9%-47·2% of MRSA-related deaths. Interpretation: Our results support targeted decolonization as an effective national intervention policy to reduce MRSA disease burden, with a minimal impact on mupirocin resistance. Funding: No