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1、,第26章 肝炎病毒,指侵犯人体肝细胞为主，并引起肝炎的病毒，有甲、乙、丙、丁、戊等种类,肝炎病毒,中国不仅是一个人口大国，而且也是病毒性肝炎的高发区。目前已知的甲、乙、丙、丁、戊、庚及TTV型肝炎，在我国均有发生，其中尤以甲、乙、丙、戊4个型别的流行情况严重。仅乙肝病毒携带者以达1.2亿之多。可以说，病毒性肝炎是对我国危害最为严重的传染病。,甲型肝炎病毒（HAV)人类甲型肝炎,病毒形态：球形，直径2729nm,核心为RNA抵抗力：-20。C可存活多年 25。C至少活1个月 毛蚶体内60。C耐受10 h 漂白粉和次氯酸钠可消除传染性,H Hepatitis AV Virus,HAV,HAV的结
2、构,甲型肝炎病毒,主要传染源：病人、隐性感染者传染方式：粪-口（fecal-oral）致病机理：,病毒进入机体,肠粘膜和局部淋巴结增殖,入血形成病毒血症,入肝并在内增殖，引起肝细胞病变,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,HAV在体内的散播,甲型肝炎有何症状？,通常有近1个月的潜伏期。病人起病急骤。开始有畏寒、发热、腹泻、腹痛、咽痛、关节痛等症状。接着出现厌食，特别是厌油腻，全身无力、恶心、呕吐，右上腹部的肝区，感到疼痛。检查时，可以发现病人肝肿大。化验检查肝功能，可有血
3、清“谷丙转氨酶”(简称ALT)升高。,症状（2）,几天以后，多数病人会出现黄疸，眼睛的巩膜（即“白眼珠”）和皮肤发黄，尿为浓茶色，大便颜色变浅，皮肤瘙痒。这个时期称为“黄疸期”。黄疸持续大约1个月后逐渐消退，其他症状也逐渐消失，肝功能恢复正常。,甲型黄疸性肝炎急性期巩膜黄染,甲型肝炎病毒,免疫性：相应抗体IgM、IgG,都对HAV的再感染有免疫作用 IgM持续2个月左右，IgG可持续多年微生物学检查：测定HAV-AbIgM有助于早期诊断,A blood test(IgM anti-HAV)is needed to diagnose hepatitis A,特异性预防prevent hepati
4、tis A virus,甲肝活疫苗 获得免疫力持久,甲肝预后,预后良好,一般不转为慢性。但需防止肝功能衰竭出现！,PERSONS WHO SHOULD RECEIVE HEPATITIS A VACCINEPersons traveling to or working in countries that have high or intermediate rates of hepatitis A Children in communities that have high rates of hepatitis A and periodic hepatitis A outbreaks Illeg
5、al-drug users Persons who have occupational risk for infection Persons who have chronic liver disease Persons who have clotting-factor disorders,How long does immunity last after hepatitis A vaccination?Although data on long-term protection are limited,estimates based on modeling techniques suggest
6、that protection will last for at least 20 years.,Can other vaccines be given at the same time that hepatitis A vaccine is given?Yes.Hepatitis B,diphtheria,poliovirus(oral and inactivated),tetanus,oral typhoid伤寒,cholera,Japanese encephalitis脑炎,rabies,yellow fever vaccine or immune globulin can be giv
7、en at the same time that hepatitis A vaccine is given,but at a different injection site.,When are persons protected after receiving hepatitis A vaccine,Protection against hepatitis A begins four weeks after the first dose of hepatitis A vaccine.,Can hepatitis A vaccine be given after exposure to hep
8、atitis A virus?,No,hepatitis A vaccine is not licensed for use after exposure to hepatitis A virus.In this situation,immune globulin should be used.,Can hepatitis A vaccine be given to immunocompromised persons?(e.g.,persons on hemodialysis or persons with AIDS)Yes.,Can hepatitis A vaccine be given
9、during pregnancy or lactation?We dont know for sure,but because vaccine is produced from inactivated hepatitis A virus,the theoretical risk to the developing fetus is expected to be low.The risk associated with vaccination,however,should be weighed against the risk for hepatitis A in women who may be at high risk for exposure to hepatitis A virus,
