抗瘧疾藥 效力減退 隱憂浮現

2009/02/12

New Fear as Malaria Drug Falters 【By THOMAS FULLER╱張佑生譯】 TASANH, Cambodia — The afflictions of this impoverished nation are on full display in its western corner: the girls for hire outside restaurants, the badly rutted dirt roads and the ubiquitous signs that warn “Danger Mines!” 柬埔寨這個赤貧國度的苦難在國境西隅一覽無遺：餐廳外面待價而沽的女孩，轍跡遍佈的泥巴路，隨處可見告示牌警告「危險，地雷！」 But what eludes the naked eye is a potentially graver problem, especially for the outside world. The parasite that causes the deadliest form of malaria is showing the first signs of resistance to the best new drug against it. 但肉眼看不見，外界尤其看不出來的是個更嚴重的潛在問題。引發最致命型瘧疾的寄生蟲，對治療該型瘧疾的最佳新藥首度出現抗藥跡象。 Combination treatments using artemisinin, an antimalaria drug extracted from a plant used in traditional Chinese medicine, have been hailed in recent years as the biggest hope for eradicating malaria from Africa, where more than 2,000 children die from the disease each day. 從傳統中國草藥青蒿提煉的抗瘧疾藥物青蒿素，用於混合療法，近年來被譽為將瘧疾自非洲根絕的最大希望。當地每天有2,000多名孩童死於瘧疾。 Now a series of studies, including one recently published in The New England Journal of Medicine and one due out soon, have cemented a consensus among researchers that artemisinin is losing its potency here and that increased efforts are needed to prevent the drug-resistant malaria from leaving here and spreading across the globe. 現在有一系列研究，包括《新英格蘭醫學期刊》最近刊出和即將刊出的一篇，強化研究者之間針對青蒿素對抗瘧疾正逐漸失效的共識，咸認各界必須更努力，才能遏止產生抗藥性的瘧疾由非洲蔓延到全球。 “This is something we can’t just slide under the carpet,” said R. Timothy Ziemer, a retired admiral in the United States Navy who heads the President’s Malaria Initiative, the $1.2 billion program started by the Bush administration three years ago to cut malaria deaths in half in the countries affected worst. 「我們不能粉飾太平，」退役美國海軍上將提摩西•齊莫爾表示。他是「總統防治瘧疾行動計畫」主持人，該計畫由前總統布希政府在三年前成立，以協助瘧疾最嚴重的國家將死亡率減半。 Admiral Ziemer met with Thai and Cambodian officials in December to assess the resistance problem, which affects the same drugs used by the malaria initiative in Africa. 齊莫爾12月會晤泰國及柬埔寨官員，評估抗藥性問題，在非洲防治瘧疾計畫使用的相同藥物也遇到同樣的抗藥性問題。 “We feel that we not only have to beat the drum but shake the cage: guys, this is significant,” he said. 他說：「我們覺得不只要敲鑼打鼓，還要搞得地動天搖，各位，茲事體大呀。」 Though the studies show relatively early signs of resistance to artemisinin, the drugs were judged to have failed in only two patients in the recently published study. Even they were eventually cured. 雖然研究證實，對青蒿素的抗藥性只是相對初步跡象，在最近發表的研究中也只對2名病人失靈，甚至連他們最後都被治癒。 But malaria experts note that several times in the past, this same area around the Thai-Cambodian border appears to have been a starting point for drug-resistant strains of malaria, starting in the 1950s with the drug chloroquine. 但瘧疾專家指出，泰柬邊界附近的同一個區域，過去有好幾次是抗藥性瘧原蟲株別的起點，始於1950年代，當時的藥物是氯奎寧。 Introduced immediately after World War II, chloroquine was considered a miracle cure against falciparum malaria, the deadliest type. But the parasite evolved, the resistant strains spread, and chloroquine is now considered virtually useless against falciparum malaria in many parts of the world, including sub- Saharan Africa. 二戰結束後隨即問世的氯奎寧，被視為對抗最致命一型惡性瘧原蟲的仙丹妙藥。但瘧原蟲演化，抗藥性株別蔓延，氯奎寧現在在世界上許多地方對抗惡性瘧原蟲被視同無效，包括撒哈拉以南非洲地區。 It took decades for this resistance to spread across the world, so by the same token artemisinin-based drugs are almost sure to be useful for many years . 對氯奎寧的抗藥性經過數十年才蔓延到全球，同理含青蒿素的抗瘧藥物幾可篤定還能用好幾十年。 To protect against artemisinin resistance, the global health authorities are trying to assure that it is sold only as a combination pill with other antimalaria medicines that linger longer in the blood, mopping up any artemisinin-resistant parasites. 為了預防對青蒿素產生抗藥性，世界衛生組織正設法確保青蒿素必須和其他抗瘧藥物一起販售，在血液中停留時間較久，消滅任何對青蒿素有抗藥性的瘧原蟲。 The two most recent tests showing artemisinin resistance were done with pills that had no combination drug. But if resistance spreads, there are no new drugs to take the place of artemisinin-based combinations and no immediate prospects under development. 對青蒿素出現抗藥性的兩項最新實驗並未使用複方藥品。但是假如抗藥性蔓延，就沒有新藥能取代青蒿素為基礎的複方藥品，研發中的藥物也沒有哪一種可以馬上問世。 “This could spread in any direction; we have to make sure it doesn’t,” said Pascal Ringwald, malaria coordinator at the World Health Organization, who three years ago led a study of drug resistance in Cambodia and is co-author of a coming study on the subject. “We know it’s not yet in Bangladesh,” he said. “It’s not yet in India.” 「問題可能朝任何方向蔓延，我們必須確保這種情況不會發生，」世界衛生組織統籌抗瘧的官員帕斯卡•林華德，3年前在柬埔寨主持一項抗藥性研究，而且是一項將發表的相關研究的共同作者。他說：「我們知道在孟加拉和印度都還沒有發生。」 The falciparum parasite is one of four types of malaria and by far the most virulent. It enters the bloodstream through a mosquito bite, and after incubating about two weeks, it multiplies and takes over red blood cells. There it causes fever, chills, headaches and nausea, among other symptoms. If untreated, the infected cells can block blood vessels and fatally cut off blood supply to vital organs. 人類瘧疾有4種，惡性瘧原蟲顯然最致命，跟著蚊子叮咬進入血流，經過2周發育，開始不斷分裂，攻占紅血球細胞，引起發燒、怕冷、頭痛、嘔吐和其他症狀。假如不治療，受到感染的細胞會阻塞血管，切斷血液流往重要器官而奪命。 Artemisinin-based combinations turned out to be fast-acting and seemed to slow transmission of the disease, said Dr. John MacArthur, an infectious disease expert with the United States Agency for International Development in Bangkok. 曼谷的美國國際開發總署傳染病專家約翰•麥克阿瑟醫師說，青蒿素類藥物證明可以迅速發揮藥效，看起來可減緩瘧疾蔓延。 Dr. MacArthur and others say resistance to malaria drugs is a natural consequence of widespread use of the drug. “In the case of malaria, it’s the Darwinism of the parasite,” he said. “It likes to survive.” 麥克阿瑟醫師和其他專家表示，產生抗藥性是廣泛使用抗瘧疾藥物的自然結果，他說：「在瘧疾病例中，這是瘧原蟲的達爾文主義，它要活下去。」 Still, some researchers remain concerned about sending the wrong message to the public about the efficacy of artemisinin-based drugs. 儘管如此，一些專家仍擔心，大家得到的是有關青蒿素類藥物療效的錯誤訊息。 “This is not the death knell of artemisinin,” said Dr. Nicholas White, a malaria expert who is chairman of a joint research program between Oxford University and Mahidol University in Thailand. “The drug still works in Cambodia, maybe not as well as before.” 牛津大學與泰國馬希竇大學一項共同研究計畫的主持人、瘧疾專家尼可拉斯•懷特醫師表示：「這不是青蒿素的末日，至少在柬埔寨仍舊有效，只是也許不像以前那麼有效。」 But given the history of drug failures here, there appears to be a consensus on the solution. “Get rid of all malaria from Cambodia,” Dr. White said. “Eradicate it. Eliminate it.” 但是，有了抗瘧藥物失靈的前車之鑑，各方對解決之道似乎已有共識。「將所有瘧疾從柬埔寨趕出去。連根拔除。徹底殲滅，」懷特說。 關鍵字句 本文介紹瘧疾藥物的抗藥性(resistance)問題，例如：This process appears to fail in insulin resistance accompanying several forms of diabetes.這個字也指身體抵抗力，如：AIDS lowers the body's resistance to infection. 汽車的風阻叫做wind/air resistance， 共同概念都是抗拒，介詞用to。經濟不景氣，產業抗拒變革，恐有破產之虞：Resistance to change has nearly destroyed the industry. 報導指出瘧疾抗藥性問題不可slide under the carpet，大掃除時髒東西往地毯下面塞，意思是將毛病隱藏起來，不加以處理，常見動詞為sweep。如：The committee is being accused of sweeping financial problems under the carpet to avoid embarrassment. 與carpet有關的片語包括形容因犯錯而遭訓斥的(be/get called)on the carpet：I got called on the carpet for being late.「在地毯上被叫」很難堪，但是roll out the red carpet(for) 指的是「隆重歡迎」。 【2009-02-10/聯合報/G9版/UNITED DAILY NEWS】