乙脑是一种人、畜共患的自然疫源性疾病,所以除人类外自然界中许多动物都可以感染乙脑病毒成为传染源。人被感染后不论发病与否都可以形成病毒血症由蚊虫叮咬进行传播。但由于人的病毒血症短暂(一般在5天以内),且病毒数量少,所以人并不是主要传染源。据调查,家畜中猪、马、牛、羊以及家禽都可感染乙脑病毒,尤其是猪、马感染率更高。在流行期间猪的感染率可达100％,且病毒血症长(3～7日)调查表明,猪的感染率高峰出现在人类流行高峰之前3～4周,若给猪进行预防接种可使人的乙脑感染率下降。主要传播媒介三带 JE is a natural foci of human and animal husbandry, so many animals in nature except humans can be infected with JE virus. Viremia can be spread by mosquito bites regardless of onset or absence of human infection. However, due to human transient viremia (usually within 5 days), and the small number of viruses, so people are not the main source of infection. According to the survey, pigs, horses, cattle, sheep and poultry in domestic animals can be infected with JE virus, especially pigs, the infection rate of horses is higher. In the prevalence of pigs up to 100% infection rate, and long viremia (3 to 7) survey showed that the peak incidence of pigs in the peak of the human epidemic 3 to 4 weeks before, if the pig vaccination can make Human JE infection rates decline. The main media three bands