Cuthbert J A
Department of Internal Medicine, UT Southwestern Medical Center at Dallas, Dallas, Texas 75390-9151, USA.
Clin Microbiol Rev. 2001 Jan;14(1):38-58. doi: 10.1128/CMR.14.1.38-58.2001.
The hepatitis A virus (HAV), a picornavirus, is a common cause of hepatitis worldwide. Spread of infection is generally person to person or by oral intake after fecal contamination of skin or mucous membranes; less commonly, there is fecal contamination of food or water. Hepatitis A is endemic in developing countries, and most residents are exposed in childhood. In contrast, the adult population in developed countries demonstrates falling rates of exposure with improvements in hygiene and sanitation. The export of food that cannot be sterilized, from countries of high endemicity to areas with low rates of infection, is a potentially important source of infection. After ingestion and uptake from the gastrointestinal tract, the virus replicates in the liver and is excreted into the bile. Cellular immune responses to the virus lead to destruction of infected hepatocytes with consequent development of symptoms and signs of disease. Humoral immune responses are the basis for diagnostic serologic assays. Acute HAV infection is clinically indistinguishable from other causes of acute viral hepatitis. In young children the disease is often asymptomatic, whereas in older children and adults there may be a range of clinical manifestations from mild, anicteric infection to fulminant hepatic failure. Clinical variants include prolonged, relapsing, and cholestatic forms. Management of the acute illness is supportive, and complete recovery without sequelae is the usual outcome. Research efforts during World War II led to the development of passive immunoprophylaxis. Pooled immune serum globulin is efficacious in the prevention and attenuation of disease in exposed individuals. More recently, active immunoprophylaxis by vaccination has been accomplished. Future eradication of this disease can now be contemplated.
甲型肝炎病毒（HAV）属于小核糖核酸病毒，是全球范围内肝炎的常见病因。感染传播通常为人际传播，或在皮肤或黏膜受粪便污染后经口摄入；较少见的情况是食物或水受到粪便污染。甲型肝炎在发展中国家呈地方性流行，大多数居民在儿童期即已接触过该病毒。相比之下，发达国家的成年人群中，随着卫生和环境卫生状况的改善，接触率呈下降趋势。从高流行率国家向低感染率地区出口无法灭菌的食品，是一个潜在的重要感染源。病毒经胃肠道摄入和吸收后，在肝脏中复制，然后排入胆汁。针对该病毒的细胞免疫反应会导致受感染肝细胞被破坏，进而出现疾病的症状和体征。体液免疫反应是诊断性血清学检测的基础。急性甲型肝炎病毒感染在临床上与其他急性病毒性肝炎病因难以区分。在幼儿中，该病通常无症状，而在大龄儿童和成人中，可能会出现一系列临床表现，从轻度无黄疸感染到暴发性肝衰竭。临床变异型包括病程延长型、复发型和胆汁淤积型。急性疾病的治疗以支持治疗为主，通常可完全康复且无后遗症。第二次世界大战期间的研究工作促成了被动免疫预防的发展。混合免疫血清球蛋白对预防和减轻暴露个体的疾病有效。最近，通过接种疫苗实现了主动免疫预防。现在可以考虑未来根除这种疾病。
