An SIRS epidemic modei with vaccination, temporary immunity and vary-ing total population size is considered. The threshold of existence of endemic equilibrium is found. The disease-free equilibrium is globally asympt...An SIRS epidemic modei with vaccination, temporary immunity and vary-ing total population size is considered. The threshold of existence of endemic equilibrium is found. The disease-free equilibrium is globally asymptotically stable below the threshold, the endemic equilibrium is globally asymptotically stable above the threshold.展开更多
Persistent hepatitis B virus(HBV)infection is a significant public health problem because it is a major cause of chronic liver disease,cirrhosis,and hepatocellular carcinoma(HCC).Roughly one-third of the world populat...Persistent hepatitis B virus(HBV)infection is a significant public health problem because it is a major cause of chronic liver disease,cirrhosis,and hepatocellular carcinoma(HCC).Roughly one-third of the world population has been infected with HBV and there are about350 million(5%-6%)persistent carriers.HBV causes80%of all liver cancer cases and is the second most important carcinogen,after smoking tobacco.There is an approximate 90%risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30%risk in pre-school children.Only 5%-10%of adults become persistent carriers following infection.Of individuals persistently infected with HBV,10%-30%will develop liver cirrhosis and HCC.These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological,viral or environmental factors.Thus,differences in host genetic factors may affect the natural history of hepatitis B.展开更多
基金Supported by the Nature Science Foundation of China (No.19971066).
文摘An SIRS epidemic modei with vaccination, temporary immunity and vary-ing total population size is considered. The threshold of existence of endemic equilibrium is found. The disease-free equilibrium is globally asymptotically stable below the threshold, the endemic equilibrium is globally asymptotically stable above the threshold.
基金Supported by National Cancer Institute,National Institute of Health,USA,No.N01-CO-12400National Nature Science Foundation of China,No.30671855International Science&Technology Cooperation Program of China,No.2014DFR31200
文摘Persistent hepatitis B virus(HBV)infection is a significant public health problem because it is a major cause of chronic liver disease,cirrhosis,and hepatocellular carcinoma(HCC).Roughly one-third of the world population has been infected with HBV and there are about350 million(5%-6%)persistent carriers.HBV causes80%of all liver cancer cases and is the second most important carcinogen,after smoking tobacco.There is an approximate 90%risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30%risk in pre-school children.Only 5%-10%of adults become persistent carriers following infection.Of individuals persistently infected with HBV,10%-30%will develop liver cirrhosis and HCC.These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological,viral or environmental factors.Thus,differences in host genetic factors may affect the natural history of hepatitis B.
