甲丙肝炎病毒

1、第第26章章 肝炎病毒肝炎病毒指侵犯人體肝細(xì)胞為主，并引起肝指侵犯人體肝細(xì)胞為主，并引起肝炎的病毒，有甲、乙、丙、丁、戊炎的病毒，有甲、乙、丙、丁、戊等種類等種類肝炎病毒 中國不僅是一個人口大國，而且也是病毒性肝炎的高發(fā)區(qū)。 目前已知的甲、乙、丙、丁、戊、庚及TTV型肝炎，在我國均有發(fā)生，其中尤以甲、乙、丙、戊4個型別的流行情況嚴(yán)重。 僅乙肝病毒攜帶者以達(dá)1.2億之多?？梢哉f，病毒性肝炎是對我國危害最為嚴(yán)重的傳染病。 甲型肝炎病毒（HAV)人類甲型肝炎 病毒形態(tài)： 球形，直徑2729nm,核心為RNA 抵抗力： -20。C可存活多年 25。C至少活1個月 毛蚶體內(nèi)60。C耐受10 h 漂白粉和

2、次氯酸鈉可消除傳染性 H Hepatitis A V VirusHAVHAV的結(jié)構(gòu)甲型肝炎病毒甲型肝炎病毒 主要傳染源：病人、主要傳染源：病人、隱性感染者隱性感染者 傳染方式傳染方式：糞：糞-口（口（fecal-oral） 致病機理：致病機理： 病毒進入機體病毒進入機體腸粘膜和局部淋巴結(jié)增殖腸粘膜和局部淋巴結(jié)增殖入血形成病毒血癥入血形成病毒血癥入肝并在內(nèi)增殖，引起肝細(xì)胞病變?nèi)敫尾⒃趦?nèi)增殖，引起肝細(xì)胞病變HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播HAV在體內(nèi)的散播甲型肝炎有何癥狀？ 通常有近1個

3、月的潛伏期。 病人起病急驟。開始有畏寒、發(fā)熱、腹瀉、腹痛、咽痛、關(guān)節(jié)痛等癥狀。接著出現(xiàn)厭食，特別是厭油膩，全身無力、惡心、嘔吐，右上腹部的肝區(qū)，感到疼惡心、嘔吐，右上腹部的肝區(qū)，感到疼痛。痛。 檢查時，可以發(fā)現(xiàn)病人肝腫大?；灆z查肝功能，可有血清“谷丙轉(zhuǎn)氨酶”(簡稱ALT)升高。癥狀（2） 幾天以后，多數(shù)病人會出現(xiàn)黃疸，眼睛的鞏膜（即“白眼珠”）和皮膚發(fā)黃，尿為濃茶色，大便顏色變淺，皮膚瘙癢。這個時期稱為“黃疸期”。 黃疸持續(xù)大約1個月后逐漸消退，其他癥狀也逐漸消失，肝功能恢復(fù)正常。甲型黃疸性肝炎急性期鞏膜黃染甲型肝炎病毒 免疫性： 相應(yīng)抗體IgM、IgG, 都對HAV的再感染有免疫作用 Ig

4、M持續(xù)2個月左右， IgG可持續(xù)多年 微生物學(xué)檢查：測定HAV-AbIgM有助于早期診斷A blood test (IgM anti-HAV) is needed to diagnose hepatitis A特異性預(yù)防prevent hepatitis A virus 甲肝活疫苗 獲得免疫力持久甲肝預(yù)后甲肝預(yù)后l預(yù)后良好,一般不轉(zhuǎn)為慢性。l但需防止肝功能衰竭出現(xiàn)！ PERSONS WHO SHOULD RECEIVE HEPATITIS A VACCINE Persons traveling to or working in countries that have high or inter

5、mediate rates of hepatitis A Children in communities that have high rates of hepatitis A and periodic hepatitis A outbreaks Illegal-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 las

6、t after hepatitis A vaccination? Although data on long-term protection are limited, estimates based on modeling techniques suggest 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

7、 (oral and inactivated), tetanus, oral typhoid傷寒, cholera, Japanese encephalitis腦炎, rabies, yellow fever vaccine or immune globulin can be given 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 Prote

8、ction against hepatitis A begins four weeks after the first dose of hepatitis A vaccine. Can hepatitis A vaccine be given after exposure to hepatitis 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 h

9、epatitis A vaccine be given to immunocompromised persons? (e.g., persons on hemodialysis or persons with AIDS) Yes. Can hepatitis A vaccine be given 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