一类考虑病毒发生变异的SIS疾病传播模型

Disease spread model with variation of virus included

为了研究变异行为对病毒传播的影响,提出了一个病毒发生变异的疾病传播模型,在模型中考虑了两种病毒相互转换的过程,计算机模拟结果表明,两种病毒的稳态感染比例与它们之间的相互转换概率γ1和γ2有关,当γ1>0且γ2=0时,I1型感染者将消失,当γ1与γ2都大于0时,I1I2与γ1γ2成反比,且与α1β1和α2β2的取值无关。研究还发现病毒变异时由于缺乏对应的治疗药物和措施而出现一段真空期,这导致变异病毒的感染比例快速增加,但真空期的出现只能增加感染者的瞬时感染比例,而对稳态感染比例没有影响。该研究对人们深入理解病毒传播机理具有启发作用。

In order to study the influence of variation on virus＇ spreading process, this paper proposed a disease spread model with variation included. In the model, the reciprocal transformation procession between two kinds of viruses was concluded. The computer simulation showed that the steady infected ratio of two viruses was related with the transformation probability of Ii them. As γ1 〉 0 and γ2 = 0 then the infected individuals of I1 will disappear. As Yl and Y2 are all above of 0, then I1/I2 was in-versely proportional to γ1 /γ2 besides I1 /I2 is irrelevant with α1/β1 and α2/β2 In addition, during the viruses＇ variation period the infec- tive ratio rised rapidly for the absence of symptomatic treatment and drugs. But which could only increase the infected ratio at the moment and had no influence to the steady infected ratio. These results can deepen people＇s understanding on virus＇ propa- gation mechanism.