新闻周刊:对抗耐药菌(7)（在线收听）

Infection specialists are also focusing on getting hospitals to do a better job at containing resistant bugs when they pop up, instead of spreading them among patient populations. About 5 percent of all patients in U.S. hospitals end up with a “nosocomial” infection—that is, an infection acquired at the hospital. It's not hard to see how. Hospitals are dense gatherings of sick people with weakened immune systems and various wounds and punctures, constantly poked and prodded by fingers and tools that move around the hospital to poke and prod others.

感染专家还致力于让医院更好地控制耐药性细菌的出现，而不是在患者中传播。在美国医院里，大约有5%的病人最终会患上“院内感染”，也就是在医院里获得的感染。不难看出原因。医院里密集地聚集着免疫力低下的病人，他们身上有各种各样的伤口和刺伤，不断地被手指和工具戳来戳去。

An aging population and new procedures have left patients all the more vulnerable. Johns Hopkins' Zenilman found in an informal survey he conducted that more than half of all the patients he asked had some sort of implant, a common source of infection. “The patients in hospitals today as a group are much sicker than any we've seen in history,” he says. “Research shows that, on average, hospitals aren't following the right precautions about half the time,” says the Association for Professionals in Infection Control and Epidemiology's Hoffmann. “It's our biggest struggle.”

人口老龄化和新的治疗方法使得病人更加脆弱。约翰霍普金斯大学的泽尼曼在他进行的一项非正式调查中发现，在他询问的所有病人中，有一半以上的人接受了某种植入物，这是一种常见的感染源。“今天医院里的病人作为一个整体比我们历史上见过的任何病人都要严重，”他表示。“研究表明，平均而言，医院有一半的时间没有采取正确的预防措施，”感染控制和流行病学专业人员协会的霍夫曼称。“这儿是我们最大的困境。”

Hospitals are beginning to change their ways. Many now use trash can–shaped robots to disinfect walls with ultraviolet light (the rooms have to be empty because the light is harmful to humans too). At Riverside Medical Center, south of Chicago, two robots from a company called Xenex disinfect more than 30 rooms a day.

医院开始改变他们的方式。现在很多人用垃圾桶形状的机器人用紫外线给墙壁消毒(房间必须是空的，因为紫外线对人类也有害)。在芝加哥南部的河畔医疗中心，来自Xenex公司的两个机器人每天为30多个房间消毒。

Keeping hospitals clean would be easier if bacteria couldn't stick to surfaces such as tabletops and clothes. Melissa Reynolds, a Colorado State University biomedical engineer, is developing new bacteria-resistant materials. Health care workers' clothing and other hospital materials and surfaces wouldn't need as much disinfection if they didn't pick up bugs in the first place. Fighting bacteria is accidental mission for Reynolds. She had been investigating ways of avoiding clots in the meshes that surgeons use to keep patients' arteries open. Applying a coating of copper nanocrystals to the meshes seemed to keep blood cells from sticking to the surfaces. She noticed that bacteria didn't stick to the nanocrystal coatings either. Then a student in her lab had a eureka moment: Why not dip cotton fabric in a solution of the nanocrystals to keep bacteria from sticking to the fabric? “We were discovering new materials with strong antibiotic properties,” says Reynolds. “That led us in a new direction.”

如果细菌不能附着在桌面和衣服等表面，那么保持医院的清洁就容易多了。科罗拉多州立大学生物医学工程师梅丽莎·雷诺兹正在开发新的抗菌材料。如果医护人员的衣服、医院的其他材料和表面一开始就没有感染病菌，就不需要那么多的消毒。对雷诺兹来说，对抗细菌是一项附加任务。她一直在研究如何避免外科医生用来保持病人动脉畅通的网状结构中出现血栓。在网格上涂上一层铜纳米晶似乎可以防止血细胞粘附在网格表面。她注意到细菌也不会粘附在纳米晶体涂层上。然后，她实验室里的一名学生灵光一闪:为什么不把棉织物浸入纳米晶体溶液中，以防止细菌粘在织物上？“我们发现了具有强大抗菌性能的新材料，” 雷诺兹说。“这把我们引向一个新方向。”