简单说来,病毒在机体内局部繁殖后,侵入血循环中称病毒血症。大多数病毒感染可发生病毒血症。病毒从血循环向全身扩散,最后可侵犯一定的组织器官(靶器官),在其中繁殖而引起病理改变,从而产生疾病。产生病毒血症的当时,不一定有症状,当病毒在靶细胞繁殖时才出现明显症状。例如天 In short, the virus in the body after local reproduction, invasion of the bloodstream called viremia. Viral sepsis can occur in most viral infections. The virus spread from the blood circulation to the whole body, and finally can invade certain tissues and organs (target organs), multiply and cause pathological changes thereby causing diseases. At that time, viremia was not necessarily symptomatic, and the virus showed obvious symptoms when the target cells were multiplied. For example, days