Optimal Control of Hepatitis B in a sub-Saharan African rural area

In this paper,we ameliorate the model proposed in[13],by incorporating the influence of hepatitis B e antigen(HBeAg)status of mothers on vertical transmission.We use the improved model to fit reported HBV new infections in the Zhejiang Province of China.Also to predict the course of the Hepatitis B(HBV)infection in this Chinese area,and in Tokombere,located in sub-Saharan Africa(SSA).Furthermore,we apply optimal control techniques in view to re-examine the effects of the newborn vaccination,the universal vaccination and the treatment of chronic carriers in preventing the HBV infection.Simulation results show that treatment slightly steps in the optimal strategy,while immunisation is an effective measure.On the other hand,they indicate that the control measures and immunization programs implemented in Zhejiang Province are effective.Besides,they suggest that in SSA,a package of several policies centred on birth dose vaccination should be implemented.

Advantages of a Novel Model for Predicting Hepatic Fibrosis in Chronic Hepatitis B Virus Carriers Compared with APRI and FIB-4 Scores

Background and Aims:Aspartate aminotransferase-toplatelet ratio index(APRI)and fibrosis-4 index(FIB-4)are widely used to assess liver fibrosis in chronic hepatitis B virus(HBV)infection.Currently,the definition of normal alanine aminotransferase(ALT)is controversial.We aimed to examine the diagnostic value of APRI and FIB-4 in chronic HBV carriers with different upper limits of normal(ULNs)for ALT.Methods:581 chronic HBV carriers were divided into the following four groups based on different ULNs for ALT:chronic HBV carriers I,II,III,and IV.Furthermore,106 chronic HBV carriers formed an external validation group.Predictive values of APRI and FIB-4 were elucidated using the area under the curve(AUC).A liver fibrosis-predictive model-GPSA(named for its measure of gamma glutamyl transpeptidase,platelet count,HBsAg and albumin)was developed using multivariate logistic regression analysis.Results:In chronic HBV carriers I,the AUCs of APRI and FIB-4 were 0.680 and 0.609 for significant fibrosis and 0.678 and 0.661 for cirrhosis,respectively.The AUCs of GPSA for significant fibrosis in the training group,internal group,and external validation group were 0.877,0.837,and 0.871,respectively.The diagnostic value of GPSA differed among chronic HBV carriers I,II,III,and IV,with AUCs for significant fibrosis being 0.857,0.853,0.868,and 0.905 and AUCs for cirrhosis being 0.901,0.905,0.886,and 0.913,respectively.GPSA showed a higher diagnostic value than APRI and FIB-4 for predicting significant fibrosis in the four groups.Conclusions:The GPSA model allows for accurate diagnosis of liver fibrosis in chronic HBV carriers with different ULN for ALT.