A delayed SEIR epidemic model with vertical transmission and non-inonotonic incidence is formulated. The equilibria and the threshold of the model have been determined on the bases of the basic reproduction number. Th...A delayed SEIR epidemic model with vertical transmission and non-inonotonic incidence is formulated. The equilibria and the threshold of the model have been determined on the bases of the basic reproduction number. The local stability of disease-free equilib- rium and endemic equilibrium is established by analyzing the corresponding character- istic equations. By comparison arguments, it is proved that, if Ro 〈 1, the disease-free equilibrium is globally asymptotically stable. Whereas, the disease-free equilibrium is unstable if R0 〉 1. Moreover, we show that the disease is permanent if the basic repro- duction number is greater than one. Furthermore, the sufficient conditions are obtained for the global asymptotic stability of the endemic equilibrium when R0 〉 1.展开更多
Chronic hepatitis B is globally prevalent and is a major cause of cirrhosis and hepatocellular carcinoma.Despite immunoprophylaxis against hepatitis B in pregnancy,perinatal transmission still occurs in at least 10%of...Chronic hepatitis B is globally prevalent and is a major cause of cirrhosis and hepatocellular carcinoma.Despite immunoprophylaxis against hepatitis B in pregnancy,perinatal transmission still occurs in at least 10%of the children born to a mother with high level of viremia.Decisions regarding hepatitis B therapy during pregnancy must take into account the benefits and safety for both the mother and the unborn baby.In this review,we summarize the current treatment options for chronic hepatitis B with a focus on management during pregnancy and the evidence-based strategies to prevent vertical transmission of hepatitis B virus(HBV).展开更多
文摘A delayed SEIR epidemic model with vertical transmission and non-inonotonic incidence is formulated. The equilibria and the threshold of the model have been determined on the bases of the basic reproduction number. The local stability of disease-free equilib- rium and endemic equilibrium is established by analyzing the corresponding character- istic equations. By comparison arguments, it is proved that, if Ro 〈 1, the disease-free equilibrium is globally asymptotically stable. Whereas, the disease-free equilibrium is unstable if R0 〉 1. Moreover, we show that the disease is permanent if the basic repro- duction number is greater than one. Furthermore, the sufficient conditions are obtained for the global asymptotic stability of the endemic equilibrium when R0 〉 1.
文摘Chronic hepatitis B is globally prevalent and is a major cause of cirrhosis and hepatocellular carcinoma.Despite immunoprophylaxis against hepatitis B in pregnancy,perinatal transmission still occurs in at least 10%of the children born to a mother with high level of viremia.Decisions regarding hepatitis B therapy during pregnancy must take into account the benefits and safety for both the mother and the unborn baby.In this review,we summarize the current treatment options for chronic hepatitis B with a focus on management during pregnancy and the evidence-based strategies to prevent vertical transmission of hepatitis B virus(HBV).
