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发表于 2004-7-28 21:37
WHO（世界卫生组织）关于乙肝的介绍
http://www.who.int/mediacentre/factsheets/fs204/en/
WHO关于饮食与日常工作不传染的介绍：“乙肝病毒不经受污染的食物或水传播，也不会在工作场所轻易传播。 ”
“Hepatitis B virus is not spread by contaminated food or water, and cannot be spread casually in the workplace.”
这是WHO的正式文件，其权威性是不容置疑的！
原文附后。
乙 肝
乙肝是人类的重要疾病之一，是一个严重的全球公众卫生问题。自1982年来开始应用安全且有效的疫苗对其进行预防。在全球20亿曾感染乙肝病毒的人群中，有超过3.5亿人为慢性HBV感染并终身携带。其中每年约100万人死于肝硬化或肝癌。虽然乙肝疫苗不能治疗慢性乙肝，但是其可对95%的人群进行有效预防而避免产生慢性感染，并因此是第一个可间接预防癌症发生疫苗。1991年，世界卫生组织号召所有儿童接种乙肝疫苗，已有116个国家把乙肝疫苗列入其常规免疫计划。但是，那些最需要疫苗的最贫穷国家的儿童却由于政府无法支付费用而一直不能接种疫苗。幸运的是，在全球疫苗与免疫联合会（GAVI）和全球儿童疫苗基金会（GFCV）的帮助下，疫苗将很快在这些国家应用。
什么是乙肝？
肝炎就是指肝脏炎症，大部分肝炎由五种病毒引起，分别甲、乙、丙、丁、戊型肝炎。这些病毒能诱发急性疾病，症状可持续数周，表现为皮肤及巩膜黄染、小便颜色变深、容易疲劳、恶心、呕吐、腹痛等。可能需数月甚至一年后才能恢复健康。乙肝病毒能引起慢性感染并让病人终身携带，数年后将发展成肝硬化或肝癌。乙肝是病毒性肝炎中较为严重的一种，是目前唯一可用疫苗预防的慢性肝炎。
谁得了乙肝？
在大多数发展中地区（如非洲撒哈拉地区、亚洲的大部分地区以及太平洋地区），大多数HBV感染者是在儿童时期感染，慢性HBV感染者占总人口中的8-10%。在这些地区死于癌症的人口中，由乙肝发展而来的肝癌位列死因前三。
亚马逊地区与东欧的南部和中欧也是乙肝高发地区。在中东与印度次大陆，大约有5%的人口是慢性HBV感染者。而在西欧与北美只有不到1%的人口是HBV感染者。
感染了乙肝病毒的孩童有可能发展成为慢性乙肝患者。约90%在1岁内感染HBV的婴儿，30-50%在1-4岁感染HBV的儿童会发展为慢性HBV感染者。在儿童时期感染HBV的慢性感染者约25%左右死于与HBV病毒相关的肝癌或肝硬化
乙肝是如何传染的？
与引起艾滋病的人类免疫缺陷病毒（HIV）的传播途径一样，乙肝病毒经接触病毒携带者的血液和体液传播。但是HBV的传染性是HIV的50-100倍。
乙肝病毒的主要传播途径是：
1.垂直传播（母婴传播）；
2.儿童间传播；
3.不安全的注射与输血传播；
4.性传播。
在全球范围内，大多数的感染发生在母婴之间、家庭内的儿童间接触、针头与注射器未经消毒重新使用。在许多发展中国家，几乎所有儿童都被乙肝病毒感染。
在许多工业化国家（如西欧与北美国家）里，传播方式又有不同。在乙肝疫苗计划被推行前，这些国家的三分之一的乙肝感染经母婴传播与儿童间传播，但目前乙肝病毒感染主要因青少年的性行为与毒品注射引起。另外，乙肝病毒是医务工作者最主要的职业感染危害，大多数医务工作者已经接种了乙肝疫苗。
乙肝病毒不经受污染的食物或水传播，也不会在工作场所轻易传播。
慢性乙肝和肝癌能被治愈吗?
肝癌几乎是致命的，通常在35－65年龄段人群中发生，这一阶段的人们也是处在事业的顶峰，肩负着家庭的责任。在发展中国家，失去一位母亲或者父亲可能会毁掉整个家庭。在发展中国家，大多数患有肝癌的人在被诊断出来后几个月内死亡。而在发达国家，通过手术和化疗能延长病人几年的寿命。部分慢性乙 型肝炎患者用干扰素或拉米夫定来治疗可获得一定效果，但干扰素与拉米夫定治疗费用为几千美元，对于发展中国家的大多数病人来说难以承担。肝硬化病人可施行肝移植手术，但成功率各异。目前对于乙肝预防胜于治疗。
乙肝疫苗的安全性与有效性有几何？
乙肝疫苗的安全性与有效性极高。自1982年后，已有超过10亿支乙肝疫苗在全球范围内使用。疫苗接种为三次肌肉注射。研究表明，乙肝疫苗可对95%未感染过乙肝病毒的人群产生免疫保护。在某些国家，曾有8-15%的儿童感染HBV，而在接种疫苗的儿童中，这个比例已下降到1％。
WHO将如何控制乙肝发展？
自1991年后，WHO即号召所有国家将接种乙肝疫苗列入本国免疫计划。到2000年3月为止，已有116个国家（包括东亚、东南亚、太平洋群岛、澳洲、北美、南美、西欧、东欧中部的大部分国家）实现此目标。但是，许多位于非洲环撒哈拉地区、印度次大陆的低收入国家和新近独立的国家没有使用疫苗。接种疫苗的费用成为在这些国家推广的最大障碍。
全球疫苗与免疫联合会（GAVI）成立于1999年，是在WHO领导下独有的公共与民间联合研究机构。GAVI的主要任务就是让尽可能多的儿童接种疫苗以抵抗各种可被疫苗预防的疾病。GAVI已经成立了一个国际健康基金：全球儿童疫苗基金会（GFCV）这个基金将帮助74个低收入国家加强实施其国家疫苗计划并引入乙肝、黄热病和B型流感嗜血菌疫苗。
==========================
原文如下：
Fact Sheet WHO/204
Revised October 2000
HEPATITIS B
Hepatitis B is one of the major diseases of mankind and is a serious global public health problem. It is preventable with safe and effective vaccines that have been available since 1982. Of the 2 billion people who have been infected with the hepatitis B virus (HBV), more than 350 million have chronic (lifelong) infections. These chronically infected persons are at high risk of death from cirrhosis of the liver and liver cancer, diseases that kill about one million persons each year. Although the vaccine will not cure chronic hepatitis, it is 95% effective in preventing chronic infections from developing, and is the first vaccine against a major human cancer. In 1991, the World Health Organization (WHO) called for all children to receive the hepatitis B vaccine, and 116 countries have added this vaccine to their routine immunization programmes. However, the children in the poorest countries, who need the vaccine the most, have not been receiving it because their governments cannot afford it. Fortunately, hepatitis B vaccine will soon be available in these countries with the assistance of the Global Alliance for Vaccines and Immunization (GAVI) and the Global Fund for Children''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s Vaccines.
What is Hepatitis?
Hepatitis means inflammation of the liver, and the most common cause is infection with one of 5 viruses, called hepatitis A,B,C,D, and E. All of these viruses can cause an acute disease with symptoms lasting several weeks including yellowing of the skin and eyes (jaundice); dark urine; extreme fatigue; nausea; vomiting and abdominal pain. It can take several months to a year to feel fit again. Hepatitis B virus can cause chronic infection in which the patient never gets rid of the virus and many years later develops cirrhosis of the liver or liver cancer. HBV is the most serious type of viral hepatitis and the only type causing chronic hepatitis for which a vaccine is available.
Who gets Hepatitis B ?
In much of the developing world, (sub-Saharan Africa, most of Asia, and the Pacific), most people become infected with HBV during childhood, and 8% to 10% of people in the general population become chronically infected. In these regions liver cancer caused by HBV figures among the first three causes death by cancer in men.
High rates of chronic HBV infection are also found in the Amazon and the southern parts of Eastern and Central Europe. In the Middle East and Indian sub-continent, about 5% are chronically infected. Infection is less common in Western Europe and North America, where less than 1% are chronically infected.
Young children who become infected with HBV are the most likely to develop chronic infection. About 90% of infants infected during the first year of life and 30% to 50% of children infected between 1 to 4 years of age develop chronic infection. The risk of death from HBV-related liver cancer or cirrhosis is approximately 25% for persons who become chronically infected during childhood.
How do people get infected ?
Hepatitis B virus is transmitted by contact with blood or body fluids of an infected person in the same way as human immunodeficiency virus (HIV), the virus that causes AIDS. However, HBV is 50 to 100 times more infectious than HIV.
The main ways of getting infected with HBV are:
Perinatal (from mother to baby at the birth);
Child- to-child transmission;
Unsafe injections and transfusions;
Sexual contact.
Worldwide, most infections occur from infected mother to child, from child to child contact in household settings, and from reuse of unsterilized needles and syringes. In many developing countries, almost all children become infected with the virus.
In many industrialized countries (e.g. Western Europe and North America), the pattern of transmission is different. In these countries, mother-to-infant and child-to-child transmission accounted for up to one third of chronic infections before childhood hepatitis B vaccination programmes were implemented. However, the majority of infections in these countries are acquired during young adulthood by sexual activity, and injecting drug use. In addition, hepatitis B virus is the major infectious occupational hazard of health workers, and most health care workers have received hepatitis B vaccine.
Hepatitis B virus is not spread by contaminated food or water, and cannot be spread casually in the workplace.
Can chronic hepatitis B and liver cancer be treated?
Liver cancer is almost always fatal, and usually develops between 35 and 65 years of age, when people are maximally productive and with family responsibilities. The loss of a mother or a father in a developing country can devastate the entire family. In developing countries, most people with liver cancer die within months of diagnosis. In industrialized countries, surgery and chemotherapy can prolong life up to a few years. Chronic hepatitis B in some patients is treated with drugs called interferon or lamivudine, which can help some patients. However, interferon or lamivudine therapy costs thousands of dollars and will never be available to most patients in developing countries. Patients with cirrhosis are sometimes given liver transplants, with varying success. It is preferable to prevent this disease with vaccine than to try and cure it.
How safe and effective is the vaccine?
Hepatitis B vaccine has an outstanding record of safety and effectiveness. Since 1982, over one billion doses of hepatitis B vaccine have been used worldwide. The vaccine is given as a series of three intramuscular doses. Studies have shown that the vaccine is 95% effective in preventing children and adults from developing chronic infection if they have not yet been infected. In many countries where 8% to 15% of children used to become chronically infected with HBV, the rate of chronic infection has been reduced to less than 1% in immunized groups of children.
How is WHO trying to control Hepatitis B?
Since 1991, WHO has called for all countries to add hepatitis B vaccine into their national immunization programmes. As of March 2000, 116 countries had included hepatitis B vaccine in their national programmes including most countries in Eastern and South- East Asia, the Pacific Islands, Australia, North and South America, Western Europe and the Middle East. However, many low income countries in sub-Saharan Africa, the Indian subcontinent and in the Newly Independent States do not use the vaccine. The price of the hepatitis B vaccine has been one of the main obstacles to its introduction in many of these countries.
The Global Alliance for Vaccines and Immunization (GAVI) was created in 1999. It is a unique coalition of public and private institutions where WHO has taken a leading role. The main mission of GAVI is to vaccinate as many children as possible against vaccine-preventable diseases. GAVI has introduced a new approach to international health funding: the Global Fund for Children''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s vaccines (GFCV). This fund will help 74 low-income countries to reinforce their national vaccine programmes and introduce hepatitis B, yellow fever and haemophilus influenzae type b(Hib) vaccines into their national immunization programmes.
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For further information, please contact the Office of the Spokesperson, WHO, Geneva. Tel (+41 22) 791 2599. Fax (+41 22) 791 4858. Email: [email protected].
[此贴子已经被金戈铁马于2004-7-30 18:12:50编辑过]
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