肠道病毒与轮状病毒

肠道病毒

学习要求 掌握 1、脊髓灰质炎病毒的致病性 2、特异性预防（剂型） 自学柯萨奇病毒 3、熟悉脊髓灰质炎病毒抵抗力、感染类型 自学埃可病毒

脊髓灰质炎病毒polio virus结构

3-D image of poliovirus

VP1 VP2 VP3 5-fold Axis 3-fold Axis 2-fold Axis

For decades, no one knew what poliovirus looked like, since viruses cannot be seen under a microscope. In 1985, a team led by James Hogle of Harvard Medical School obtained high-resolution, 3D images of poliovirus, and today, the newly formed Children's Hospital Boston -- Harvard Medical School structural biology unit is heir to the Enders tradition.

Led by Stephen Harrison, this group is using a variety of sophisticated tools like X-ray crystallography and molecular electron microscopy to obtain detailed, dynamic, 3D views -- accurate down to the atom -- of how viruses move, transfer information and reconfigure themselves to attack their victims. These images are shedding light on many of today's viral scourges, such as HIV, dengue and rotavirus, and providing new leads for treatment and vaccine development.

Polio virus

An ancient Egyptian stele, portraying a prince with a withered leg - probably polio. © WHO/GPEI

埃及第十八朝的这块石碑可能是脊髓灰质炎病例的最早记载。

Polio ‘Last Cases’ Americas Region Luis Fermin Tenorio Peru 1991 Western Pacific Region Mum Chanty Cambodia 1997 European Region Melik Minas Turkey 1998 Polio Eradication

Small thin stem on a tree See for a moment Researchers Glimpse Polio Virus as it Enters Host Cell Contact: 3-D structures The image on the left shows a naked polio virus. The polio virus on the right is studded with 60 twig-like structures, the receptors. Small thin stem on a tree

WHO Polio cases have decreased by 99.8% since 1988, from an estimated 350 000 cases to 483 in 2001*. The reduction is the result of the global effort to eradicate the disease.

Areas with high-intensity transmission Together, these countries accounted for more than 85% of the new polio caseload in 2001. They are characterized by having areas with large populations and low routine immunization coverage, sub-optimal sanitation and relatively wide geographical distribution of the wild poliovirus. These countries are: India Pakistan/Afghanistan Nigeria/Niger

Polio was declared eradicated in the U.S. in 1979. Yet according to the World Health Organization, polio cases worldwide rose by a third in 2004, due in part to vaccine boycotts. Children's and Spaulding Rehabilitation Hospital are still seeing new cases -- the result of international adoptions from Third World countries and from Russia.

病毒抵抗力 在污水和粪便中可活数月 食品中可保存数周 不易被胃酸或胆汁灭活 对氧化剂敏感 56。C30min被灭活

致病性 传染源：病人或无症状携带者 传染方式：粪-口途径 致病机理

二、致病性 咽部、肠壁淋巴组织 入血流 病毒 入全身淋巴组织 再次入血流 延髓和脑干：延髓型 大脑运动皮质区：脑炎型 第1次病毒血症 第2次病毒血症 病毒入脊髓前角运动神经细胞：（脊髓型） 延髓和脑干：延髓型 大脑运动皮质区：脑炎型

感染类型 人群中绝大多数为隐性感染或轻型感染 显性感染 引起麻痹者仅为显性感染的0.1%-1% 顿挫感染

免疫性 SIgA：清除肠道内病毒，阻止病毒入血 IgM,IgG:阻断血流中病毒向中枢神经系统扩散 感染后获得对同型病毒较牢固的免疫力

预防 口服脊髓灰质炎减毒活疫苗糖丸(1957年发明） Oral vaccination with live vaccine Vaccination programs have eradicated it from the Western world and promise to eliminate it globally Dr Alber Sabin

疫苗使用的效果

新进展Date: Thu, 11 Jul 2002 Scientists have built the virus that causes polio from scratch in the lab, using nothing more than genetic sequence information from public databases and readily available technology. The fact proves that even if all the polio virus in the world were destroyed, it would be easily possible to resurrect the crippling disease, says Aniko Paul at the State University of New York at Stony Brook, one of the researchers conducting the study. Bring back into use

Journal reference: Science (DOI: 10.1126/science.1072266) The result has major implications for vaccination programs that have nearly rid the world of polio. "I think it means you're probably not going to be able to stop vaccinating people even after you eradicate the virus," says Diane Griffin of the Johns Hopkins Bloomberg School of Public Health.

Paul believes the synthesis method could be applied to other viral diseases."We feel this could be used for ebola, smallpox, just about anything," she says. This raises the worrying possibility that bioterrorists could use a similar approach to create devastating diseases without having to gain access to protect viral stocks.

Summary of polio virus paralysis electron microscopy and X-ray crystallography. vaccination programs have eradicated it from the Western world and promise to eliminate it globally Surprisingly little is known about how poliovirus enters the cells of the intestines, let alone how it makes its way to the nervous system where it can damage motor neurons and cause paralysis

轮状病毒

形态 核心为dsRNA，外有双层衣壳，内外两层呈放射状排列

轮状病毒 分组： A、B、C组：可引起人、动物腹泻， 最常见A组(有称为小儿轮状病毒） D-G组：仅引起动物腹泻 A组抵抗力： 耐乙醚、弱酸 室温中传染性可保持7个月 -20。C长期保存

A组轮状病毒 所致疾病： 婴幼儿尤其秋冬季急性胃肠炎 传播途径：粪-口途径 所致疾病： 婴幼儿尤其秋冬季急性胃肠炎 传播途径：粪-口途径 机理：病毒在十二指肠粘膜细胞中增殖 影响肠道对水、盐的正常吸收 腹泻（粪便绿或白色），常伴发热，严重者可出现脱水或酸中毒

B组轮状病毒 引起成人腹泻 我国1982年首先发现

特异性预防 尚无疫苗接种

思考题 为什么预防脊髓灰质炎的预防针选用口服制剂？