EV71与肠道病毒

肠道病毒在病毒微生物学上的分类是属于微小病毒科中的肠道病毒群。肠道病毒71型,简称EV71。肠道病毒一般是以数字命名的,排列顺序代表着其发现的先后次序。按顺序，这种病毒被命名为肠道病毒71型。EV71为目前肠道病毒群中最晚发现的病毒，其感染性强且致病率高，尤其是神经系统方面的并发症。于1997年造成偶蹄动物感染的口蹄疫病毒也与肠道病毒一样同属于微小病毒科，因此，当1998年台湾地区肠道病毒大流行时，便有舆论认为引起人类手足口病，主要是由于对感染口蹄疫的病死猪做掩埋处理不当因而污染环境，导致病毒反扑所致。事实上，肠道病毒与口蹄疫病毒虽然属于同一病毒科但却是截然不同的两种病毒，故此二者的致病机制并无直接相关性。

肠道病毒在病毒学上的分类是属于无外套膜的病毒，因此它对于周遭环境的抵抗力很强，耐酸性很好，故不会被胃酸破坏，可以通过胃酸到达肠道繁殖，这也是它被命名为肠道病毒的原因之一。肠道病毒对乙醇亦具耐受性，故酒清对肠道病毒并无抑制作用。肠道病毒甚至可以对抗一般的清洁剂，故一般家庭用的洗手乳及肥皂对肠道病毒无杀菌效果。因肠道病毒可在下水道污水中存活3～5天之久，故在肠道病毒大流行期间甚至可由下水道污水中分离出肠道病毒。目前已知需浓度约1～3%的漂白水才能有效地消灭肠道病毒，因此在大流行期常用此浓度的漂白水对病患所接触过的物品及环境进行喷洒消毒。

肠道病毒的流行与季节转换、环境变异有着极大的关联性，肠道病毒只在夏季及初秋流行，每年6～9月为高峰期，气温过低的地区并不利于肠道病毒生存。根据流行病学调查，肠道病毒的传染途径主为粪或者口传染，感染肠道病毒的患者会经由粪便排出病毒，这些含有高浓度肠道病毒的粪便会污染环境甚至地下水源，在公共卫生条件不佳的地区，极易经由污染的水源而散播该病毒。由于肠道病毒除了在肠道外亦可在扁桃腺增殖，因此病患的唾液或口鼻分泌物也会带有高浓度的病毒，所以不排除经由空气或接触等传染途径。由以上两点可知，防治肠道病毒的流行,除了重视个人卫生外，公共卫生及环境卫生亦不容忽视。

由流行病学资料显示，EV71具有季节性且无地域性限制，故于全世界各地均有病毒流行报告，包括澳洲、日本、香港、马来西亚、瑞典、保加利亚、匈牙利及法国等。然而出现肠道病毒致死病例的却只有少数地区。依据这些地区的病毒流行报告显示，EV71侵犯的对象主要为学龄前幼童，而由1998年台湾地区EV71大流行时之统计数据发现，三岁以下之幼儿几乎都无EV71之抗体，故为最主要之高危险群。

目前检测肠道病毒之方式除了传统的病毒培养鉴定法外，国内已有生物科技公司利用生物芯片技术研发出“肠道病毒鉴定芯片”，可快速检测出肠道病毒之型别，不致延误病患就诊治疗的首要时机。因肠道病毒感染易引起并发症，且往往在一星期内即转成重症，所以若能提早确知所感染的病毒类型，即可掌握对症治疗的第一时间。

小题1:请根据文意用简洁语言给“EV71病毒”下一个定义。（3分）

小题2:指出下列句子中加线的词语所指的具体内容。（4分）

① 这也是它被命名为肠道病毒的原因之一。

② 由以上两点，可知，防治肠道病毒之流行除了重视个人卫生外，公共卫生及环境卫生 亦不容忽视。

小题3:肠道病毒具有哪些特点？根据文意，分点概括回答。（3分）

小题4:“EV71病毒”能够导致人类患上手足口病等病症,人类该如何预防这些疾病的发生?请你结合文意及自己的认识简要解答。（4分）

Brenda Bongos was a happy, artistic girl. She had one big dream—to play the drums in a band. But one big problem lay in her way. To be good enough to play in a band, Brenda had to practice a lot, but she lived next-door to a lot of old people. Many of them are sick. She knew that the sound of beating drums would really get on their nerves. So, she had tried playing in the strangest places: a basement, a kitchen, and even in a shower. But there was always someone it would annoy.

One day, while watching a science documentary on TV, she heard that sound cannot travel in space, because there's no air. At that moment, Brenda Bongos decided to become a sort of musical astronaut.

With the help of a lot of time, books and work, Brenda built a space bubble. This was a big glass ball connected to a machine which sucked out all the air inside. All that would be left inside was a drum kit（成套设备） and a chair. Brenda got into the space suit she had made, entered the bubble, turned on the machine, and played those drums like a wild child.

It wasn't long before Brenda Bongos came very famous. Many people came to see her play in her space bubble. Shortly afterwards she came out of the bubble and started giving concerts. Her fame spread so much that the government suggested that she be part of a unique space journey. Finally, Brenda was a real musical astronaut, and had gone far beyond her first ambition of playing drums in a band.

Years later, when asked how she had achieved all this, she thought for a moment, and said: ''If those old people next–door hadn't mattered so much to me, I wouldn't have found a solution, and none of this would have ever happened.''

小题1:Why did Brenda try to play in the strangest places?

A．Because she didn't want others to hear her play

B．Because she didn't mean to disturb others.

C．Because she didn't have her own room

D．Because she didn’t like her neighbors.小题2:Brenda started to give concerts _______.

A．after she practiced in her space bubble

B．when she became part of the unique space journey

C．after she became a real musical astronaut

D．when people came to see her in the space bubble小题3:Brenda became famous because _______.

A．she was good at music and science

B．she became a real musical astronaut

C．she invented a special way of practice

D．she played well and had a talent小题4:It can be inferred from the text that: " _______".

A．He laughs best who laughs last

B．It's never too old to learn

C．Two heads are better than one

D．One good turn deserves another