Livestock transportation is a key factor that contributes to the spatial spread of brucellosis.To analyze the impact of sheep transportation on brucellosis transmission,we develop a human–sheep coupled brucellosis mo...Livestock transportation is a key factor that contributes to the spatial spread of brucellosis.To analyze the impact of sheep transportation on brucellosis transmission,we develop a human–sheep coupled brucellosis model within a metapopulation network framework.Theoretically,we examine the positively invariant set,the basic reproduction number,the existence,uniqueness,and stability of disease-free equilibrium and the existence of the endemic equilibrium of the model.For practical application,using Heilongjiang province as a case study,we simulate brucellosis transmission across 12 cities based on data using three network types:the BA network,the ER network,and homogeneous mixing network.The simulation results indicate that the network's average degree plays a role in the spread of brucellosis.For BA and ER networks,the basic reproduction number and cumulative incidence of brucellosis stabilize when the network's average degree reaches 4 or 5.In contrast,sheep transport in a homogeneous mixing network accelerates the cross-regional spread of brucellosis,whereas transportation in a BA network helps to control it effectively.Furthermore,the findings suggest that the movement of sheep is not always detrimental to controlling the spread of brucellosis.For cities with smaller sheep populations,such as Shuangyashan and Qitaihe,increasing the transport of sheep outward amplifies the spatial spread of the disease.In contrast,in cities with larger sheep populations,such as Qiqihar,Daqing,and Suihua,moderate sheep outflow can help reduce the spread.In addition,cities with large livestock populations play a dominant role in the overall transmission dynamics,underscoring the need for stricter supervision in these areas.展开更多
针对2019年底暴发的新型冠状病毒肺炎,中国政府采取了一系列严格的防控措施,其中起关键作用的是普通民众的居家隔离与密切接触者的追踪隔离.建立新型冠状病毒传播与控制动力学模型,定量评估这两项措施的有效性.利用下一代矩阵法计算了...针对2019年底暴发的新型冠状病毒肺炎,中国政府采取了一系列严格的防控措施,其中起关键作用的是普通民众的居家隔离与密切接触者的追踪隔离.建立新型冠状病毒传播与控制动力学模型,定量评估这两项措施的有效性.利用下一代矩阵法计算了基本再生数和有效再生数,给出了有效再生数的极限范围,分析了模型的动力学特征.以安徽省为例,利用MCMC(Markov chain Monte Carlo)参数估计方法进行数值拟合,得到安徽省新型冠状病毒传播模型的基本再生数为0.4021(95%CI:0.3973~-0.4070),有效再生数的极限范围为[0,0.048745].随着隔离措施的有效实施,安徽省的有效再生数迅速下降到0.05以下并趋于0.048735,疫情及时得到了控制.如果没有采取这些隔离措施,基本再生数为2.1030(95%CI:2.0804~2.1255),疾病将会在人群中持续传播.通过参数敏感性分析,发现加强密切跟踪隔离力度,即增加染病者的隔离速率系数,能够有效降低基本再生数;加强居家隔离力度,即增加易感者的隔离速率系数与减少易感者的隔离解除速率系数,有助于降低有效再生数极限范围的上界.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12101443,12371493)the Natural Science Foundation of Shanxi Province(Grant Nos.20210302124260 and 202303021221024)。
文摘Livestock transportation is a key factor that contributes to the spatial spread of brucellosis.To analyze the impact of sheep transportation on brucellosis transmission,we develop a human–sheep coupled brucellosis model within a metapopulation network framework.Theoretically,we examine the positively invariant set,the basic reproduction number,the existence,uniqueness,and stability of disease-free equilibrium and the existence of the endemic equilibrium of the model.For practical application,using Heilongjiang province as a case study,we simulate brucellosis transmission across 12 cities based on data using three network types:the BA network,the ER network,and homogeneous mixing network.The simulation results indicate that the network's average degree plays a role in the spread of brucellosis.For BA and ER networks,the basic reproduction number and cumulative incidence of brucellosis stabilize when the network's average degree reaches 4 or 5.In contrast,sheep transport in a homogeneous mixing network accelerates the cross-regional spread of brucellosis,whereas transportation in a BA network helps to control it effectively.Furthermore,the findings suggest that the movement of sheep is not always detrimental to controlling the spread of brucellosis.For cities with smaller sheep populations,such as Shuangyashan and Qitaihe,increasing the transport of sheep outward amplifies the spatial spread of the disease.In contrast,in cities with larger sheep populations,such as Qiqihar,Daqing,and Suihua,moderate sheep outflow can help reduce the spread.In addition,cities with large livestock populations play a dominant role in the overall transmission dynamics,underscoring the need for stricter supervision in these areas.
文摘针对2019年底暴发的新型冠状病毒肺炎,中国政府采取了一系列严格的防控措施,其中起关键作用的是普通民众的居家隔离与密切接触者的追踪隔离.建立新型冠状病毒传播与控制动力学模型,定量评估这两项措施的有效性.利用下一代矩阵法计算了基本再生数和有效再生数,给出了有效再生数的极限范围,分析了模型的动力学特征.以安徽省为例,利用MCMC(Markov chain Monte Carlo)参数估计方法进行数值拟合,得到安徽省新型冠状病毒传播模型的基本再生数为0.4021(95%CI:0.3973~-0.4070),有效再生数的极限范围为[0,0.048745].随着隔离措施的有效实施,安徽省的有效再生数迅速下降到0.05以下并趋于0.048735,疫情及时得到了控制.如果没有采取这些隔离措施,基本再生数为2.1030(95%CI:2.0804~2.1255),疾病将会在人群中持续传播.通过参数敏感性分析,发现加强密切跟踪隔离力度,即增加染病者的隔离速率系数,能够有效降低基本再生数;加强居家隔离力度,即增加易感者的隔离速率系数与减少易感者的隔离解除速率系数,有助于降低有效再生数极限范围的上界.
