耦合不同年龄层接触模式的新冠肺炎传播模型

搜集广东省自1月23日到2月16日期间944例新冠肺炎样本信息.对确诊人群进行年龄特征分析,将人群分为儿童组(0—5岁)、青少年组(6—19岁)、中青年组(20—64岁)、老年组(65岁及以上),耦合不同年龄层的接触模式,建立离散年龄结构新冠肺炎模型,得出模型的基本再生数及最终规模.通过蒙特卡罗数值算法(MCMC)辨识模型的参数、拟合累计病例数、计算消亡时间、感染峰值及到达时间等有关生物量.研究发现中青年人群感染人数最多;相比于居家模式,社区模式下中青年人群感染峰值上升41%,峰值推迟一周到达.通过分析不同年龄层的最终规模在对应年龄层的占比,发现老年人的易感性较高,青少年的易感性相对较低.在居家模式下,若各年龄层患者能及时就诊,住院峰值将进一步减少,但住院高峰将提前一周到达.此模型可揭示个体接触行为对新冠肺炎的传播的影响,定量评价居家隔离措施的有效性.

Study of coupling the age-structured contact patterns to the COVID-19 pandemic transmission

Background:The coronavirus disease 2019(COVID-19)has raged more than 10 months and it has become a major public health concern.It is necessary to account for the intrinsic mechanisms and reveal the transmission pattern.Method:We collect detailed information of 944 COVID-19 cases in Guangdong province from January 23rd to February 16th.According to the age-structured characteristics,the population is divided into four groups such as child group(0–5 years old),adolescent group(6–19 years old),young and middle-aged group(20–64 years old),elderly group(65 and over years old).Coupling with different age-structured contact patterns,we establish a discrete age-structured COVID-19 model,obtain the basic reproduction number and final size.By Markov Chain Monte Carlo numerical method(MCMC),we identify the model parameters,fit the cumulative cases,calculate eradiation time of disease,infection peak and the peak arrival time,etc.Results:We found that the most infected people are the young and middle-aged individuals;Compared with household quarantine measure,the peak value of hospitalizations among young and middle-aged group in community mode will increase of 41%,and the peak will delay two weeks.By analyzing the proportions of the final sizes associated age groups,it is found that the elderly have a higher susceptibility,while the adolescents have a lower susceptibility.Under the household quarantine measure,if infected individuals have been confirmed in time of half a day,the peak size of hospitalizations will be further reduced,and the peak hospitalization will advance one week.The model reveals social contact patterns for impacting on COVID-19 transmission,and evaluates the effectiveness of household quarantine.