多重抗藥性結核病（mdrtb）的防治

多重抗藥性結核病（ MDR-TB)的防治 周振興 l多重抗藥性結核病（ MDR-TB ）是指 結核病人的痰檢體經培養及藥物敏感性試 驗後發現至少同時對 Isoniazid （ INH ）及 Rifampin （ RMP ）二種第一線藥物具有 抗藥性的病人 (廣泛抗藥性結核菌Extensively drug resistant tuberculosis,XDR-TB ) l若更嚴重進一步對任何 fluoroquinolone 藥物有抗 藥性，且對於 3 種注射型的抗結核病二線藥物 （ capreomycin, kanamycin, amikacin ）中至少 1 種出現抗藥性者，就會成為所謂超級抗藥性結 核 (Extensively drug resistant tuberculosis, XDR-TB ；亦有翻譯為廣泛抗藥性結核菌 ) lXDR-TB 的出現無異使結核病防治上更加困難， 治療上比 MDR-TB 更為棘手，一旦被感染，其治 療成功率有可能會降至 50% 以下 廣泛抗藥性結核菌 l美國疾病管制中心和世界衛生組織 於2006年初發 出警告，一種全新、致命性高的廣泛抗藥性結核 菌正在全球擴散。 l 2006年8月在加拿大多倫多舉行的國際世界愛 滋病會議(International World AIDS Conference ) 中，與會人士報告了南非東南部省 分夸祖魯-納塔爾 (KwaZulu-Natal ) 發生53例XDR -TB病人中，有52人平均在二十五天內死亡，且 44病人合併感染愛滋病 Prevalence of drug resistance among new TB cases Anti-tuberculosis drug resistance in the world, report No.2 WHO 2000 The World Health Organization (WHO) surveyed 62,746 M. tuberculosis isolates from 81 countries between 2002 and 2006 lmultidrug-resistant tuberculosis (MDR-TB) represented 5.3 percent of all new and previously treated TB cases worldwide. lChina, India, and the Russian Federation, are estimated to carry the highest number of MDR- TB cases. lChina and India have approximately 50 percent of the global burden of MDR-TB cases lThe rates of MDR-TB are increasing in Peru, the Republic of Korea, and some parts of the Russian Federation (Orel and Tomsk) lOf the 4,012 MDR cases that were reported, 301 (7 percent) were XDR-TB. lThe proportion of XDR-TB among MDR- TB ranged from zero percent in 11 countries to 30 percent in Japan. l國內的抗藥性監測資料在 2006 年底以前是 來自於各醫院的研究資料收集得之，多重 抗藥性結核病的比率從 0.2% （ 1984-1990 ）一直逐年往上升至 2% （ 1997-2000 ） 。 lWhen organisms are resistant to both isoniazid and rifampin, the course of treatment increases from 6 months to 18- 24 months, and the cure rate decreases from nearly 100% to less than or equal to 60%. 結核初次治療的藥品費用 (複方) 藥品單價每日平均劑量每日費用 RFT11.5557.5 RFN30013.5227 RFN1507.5322.5 EMB1.923.8 50kg 初治 2 (RFT+E)/4 (RFN+E) 藥品費用： 7374 初治 9 (RFN+E) 藥品費用： 8316 抗藥性結核治療的藥品費用 藥品健保單價每日平均劑量每日費用 Levofloxacin (500) 1521.5223 PAS6.520130 TBN6.5319.5 CS46.9293.8 SM52152 KM15.0115.0 LEVO+PAS+TBN+CS+SM 每月藥品費用：15549 治療 21 個月 藥品費用：298449 MDR-TB產生原因 結核菌發生抗藥性突變的機率 Shimao T. Tubercle 1988;68(supp):5-15. 分 裂 突 變 抗藥性結核菌如何發生 (續) INH 抗藥 INH+RMP 抗藥 INH+PZA 抗藥 INH+RMP 多重抗藥 性結核菌 INH + RMP 單一治療 “Fall and Rise” Phenomenon 人為因素 l診療醫師處方錯誤： （一） 針對活動性結核病人施行預防治療。 （二） 未依標準處方及劑量開立結核藥物。 （三） 未注意到病人服藥順服度不佳，或雖知道但未採 取行動。 （四） 未注意到病人已經罹患抗藥結核病。 （五） 在失敗的處方每次新增 1 種藥物。 （六） 過度信賴 streptomycin 及 fluoroquinolone ， 誤以為已使用 2 種新藥，卻忽略了 streptomycin 無法在 18-24 個月的療程中全程使用，以及 streptomycin 可能與 isoniazid 共同出現抗藥的問題。 人為因素 l來自病人的問題如下： （一） 服藥順服度差導致續發性多重抗藥 菌株的產生。 （二） 因藥物副作用導致不規則服藥。 （三） 遭原發性多重抗藥菌株感染。 （四） 因肺生理結構扭曲所導致的生理性 抗藥（ Physiological resistance ）。 診斷 Persons at Increased Risk for Drug Resistance History of treatment with TB drugs Contacts of persons with drug-resistant TB Foreign-born persons from high prevalent drug resistant areas Smears or cultures remain positive despite 2 months of TB treatment Received inadequate treatment regimens for 2 weeks Culture and sensitivity lThe diagnosis of drug-resistant tuberculosis depends upon the collection and processing of adequate specimens for culture and sensitivity testing lNeed 2 more months MOLECULAR BASIS OF DRUG-RESISTANT TUBERCULOSIS lIsoniazid resistance Alterations in either the katG, kasA, or inhA genes lRifampin resistance Mutations in the rpoB gene lPyrazinamide resistance mutations in the gene pncA lEthambutol resistance- amino acid replacements at position 306 of an arabinosyltransferase encoded by the embB gene lStreptomycin Resistance is conferred by mutations in the rpsL and rrs genes Rapid testing lA molecular probe capable of detecting resistance mutations in three TB genes: rpoB (associated with rifampin resistance), and katG and inhA (mutations associated with isoniazid resistance) lthe molecular probe was 99 percent sensitive and specific for multidrug TB resistance, compared with standard drug-susceptibility testing; results were available in 1 to 2 days. lSince the assay does not depend on culture, it yielded results even in specimens that were contaminated or had no growth. TREATMENT OF MDR-TB antituberculosis drugs Empiric lInclude the standard recommendations plus lat least four drugs effective against the most prevalent drug-resistant strains l This may require that six or more drugs be given until drug susceptibility results are obtained Documented MDR ldiscontinue the drugs to which the isolate is resistant and to add at least two new drugs to which the isolate is susceptible lmost experts recommend that a parenteral aminoglycoside (streptomycin, kanamycin, amikacin, or capreomycin) and a quinolone (levofloxacin and moxifloxacin) be added. lTreatment with parenteral agents is usually given for six months, and cures rates are high with medical therapy alone (in the 85 percent range) for MDR-TB regimens that include these two classes of drugs lTreatment with at least four effective drugs should be continued for 18 to 24 months lappropriate laboratory facilities to document drug susceptibility and monitor response should be available. lThese regimens should be administered by direct observation Adjunctive therapies l Uncontrolled trials and anecdotal reports suggest that adjunctive immunotherapy with interferon-gamma (IFNg) may be useful in the management of multidrug- resistant tuberculosis lSmall observational studies suggested benefit in MDR-TB. However, a randomized trial of IFNg failed to confirm efficacy Criteria for Surgery in MDR-TB lLocalized lesions lReasonable lung function lTwo or more susceptible drugs available Directly observed therapy lA decrease in the incidence rate of pulmonary TB (from 42 to 19 per 100,000 population) lA decreases in the rate of primary drug resistance (from 9.4 to 1.5 per 100,000 population) lA decrease in treatment failures (from 11 to 2 percent) lA decrease in the rate of MDR-TB (from 10 to 4.3 per 100,000 population) 治療照護 治療多重抗藥及慢性病人應有下列資源到位，診療醫師如資 源不足，應儘速將其轉診至適當醫療團隊。 1. 經驗豐富的結核病醫療團隊，含醫師、護理人員， 社會工作人員、營養師等。 2. 能提供高品質藥敏試驗、菌種鑑定的結核菌實驗室。 3. 充足且來源穩定的二線藥物。 4. 多重抗藥及慢性病人如有住院需求，應安置於具完善院 內感染控制的病房。 世界衛生組織建議：如以良好的居家照護為基礎，在合格 的醫療團隊指導下，可由經完整訓練的健康照護工作人員 提供多重抗藥與慢性病人全程居家治療，以避免抗藥結核 病的院內感染。 政府作為 l有鑑於多重抗藥性結核病的治療複雜及嚴重影響 國人健康，現在國內已建置更專業的多重抗藥（ MDR ）醫療照護體系可協助這些病人的醫療照護 ; 包括台北市立萬芳醫院團隊、行政院衛生 署桃園醫院團隊、行政院衛生署台中醫院團 隊、行政院衛生署胸腔病院團隊、中華 民國防癆協會團隊的成立 l2006 年起建立 MDR-TB 通報系統，推動進階都 治計畫（ DOTS plus ）以及時監控所有多重抗藥 性結核病患，避免衍生出更多超級抗藥性結核病 患。 預防 l針對無抗藥性結核病，正確的一線藥物治 療、適當的管理是預防抗藥性結核病產生 的最佳方法。 Drug-susceptible TB and MDR TB are spread the same way lshaking someones hand lsharing food or drink ltouching bed linens or toilet seats lsharing toothbrushes lkissing How can MDR TB be prevented? ltake all of their medications exactly as prescribed by their health care provider. lHealth care providers can help prevent MDR TB by quickly diagnosing cases, following recommended treatment guidelines, monitoring patients response to treatment, and making sure therapy is completed. lavoid exposure to known MDR TB patients in closed or crowded places such as hospitals, prisons, or homeless shelters. lIn the United States drug-resistant tuberculosis prevalence has decreased compared with the early 1990s (3.5 percent in 1991 versus 1.1 percent in 2006) and has remained stable between 2005 (1.2 pe