Gujarati Tanvi P, Ambika G
Indian Institute of Science Education and Research, TVM, Thiruvananthapuram, 695016, Kerala, India,
J Math Biol. 2014 Dec;69(6-7):1773-800. doi: 10.1007/s00285-013-0749-4. Epub 2014 Jan 4.
Dengue viral infections show unique infection patterns arising from its four serotypes, (DENV-1,2,3,4). Its effects range from simple fever in primary infections to potentially fatal secondary infections. We analytically and numerically analyse virus dynamics and humoral response in a host during primary and secondary dengue infection for long periods using micro-epidemic models. The models presented here incorporate time delays, antibody dependent enhancement, a dynamic switch and a correlation factor between different DENV serotypes. We find that the viral load goes down to undetectable levels within 7-14 days as is observed for dengue infection, in both cases. For primary infection, the stability analysis of steady states shows interesting dependence on the time delay involved in the production of antibodies from plasma cells. We demonstrate the existence of a critical value for the immune response parameter, beyond which the infection gets completely cured. For secondary infections with a different serotype, the homologous antibody production is enhanced due to the influence of heterologous antibodies. The antibody production is also controlled by the correlation factor, which is a measure of similarities between the different DENV serotypes involved. Our results agree with clinically observed humoral responses for primary and secondary infections.
登革病毒感染因其四种血清型（DENV - 1、2、3、4）呈现出独特的感染模式。其影响范围从初次感染时的单纯发热到可能致命的二次感染。我们使用微观流行模型对初次和二次登革热感染期间宿主内的病毒动态和体液反应进行了长期的分析和数值分析。这里提出的模型纳入了时间延迟、抗体依赖增强、动态切换以及不同登革病毒血清型之间的相关因子。我们发现，在这两种情况下，病毒载量在7 - 14天内降至检测不到的水平，这与登革热感染的观察结果一致。对于初次感染，稳态的稳定性分析显示出对浆细胞产生抗体所涉及的时间延迟的有趣依赖性。我们证明了免疫反应参数存在一个临界值，超过该临界值感染会完全治愈。对于不同血清型的二次感染，由于异源抗体的影响，同源抗体的产生会增强。抗体产生也受相关因子控制，该因子衡量了所涉及的不同登革病毒血清型之间的相似性。我们的结果与初次和二次感染的临床观察到的体液反应一致。
