The Epidemiological Trend And The Burden Of Diseases Of Hepatitis B, Liver Cirrhosis And Liver Cancer In Shandong Province Of China

【Background】Hepatitis B is a serious infectious disease caused by hepatitis B virus (HBV) which could induce chronic hepatitis, cirrhosis and hepatocellular carcinoma. Among the people who infected by HBV,10% of those will progress to chronic hepatitis B, and chronic hepatitis B patients have 10% converted to cirrhosis, and liver cirrhosis patients have 10% developed to liver cancer. HBV infection is one of the important public health issues in Shandong province which is not only a serious health hazard to residents but also create serious economic burden. Three times of hepatitis B sero-epidemiological investigation were carried out in China in 1979,1992 and 2006, respectively.The survey in 1992 indicated that China was a high infection country with 9.75% of HBsAg positive rate and 57.63% of HBV cumulative prevalence rate. The basic discipline and the prevalent stenth in 1992 were the same with the survey in 1979. The rate of people with HBsAg was 7.2% in Shandong province. In 2006, the rate of people took along HBsAg was 3.39% in Shandong province. Although the trend was clearly down compared to 1992, but the number of reported cases was still living the forefront of legal reporting infectious diseases.Burden of disease (BOD) can be split into two aspects:epidemic burden (health burden) and economic burden. Disease burden on population health insists of fatal and non-fatal damage. The economic burden of disease insists of direct economic burden and indirect economic burden. The former is usually made up with direct medical costs and direct non-medical costs, and the latter can be divided into mortality costs and morbidity costs. Estimating the economic burden of disease is an important tool to evaluate the perniciousness of disease further and make health policy effectively.【Objectives】1. To analysis the epidemiological trend of hepatitis B, liver cirrhosis and liver cancer during 1990 to 2007 in Shandong province of China, and to compare the tendency of the gender- specific and age-specific incidence rate and mortality rate.Evaluate the effect of hepatitis B prevention since vaccination of hepatitis B vaccine, in order to provide a scientific basis for the future devise control strategies.2. To evaluate the disease burden of hepatitis B, cirrhosis and liver cancer, and calculate the burden of disease due to hepatitis B virus infection.To understand hepatitis B and its related diseases impact on the overall socio-economic and health.【Methods】First of all, collection of information on the incidence of Hepatitis B and mortality data of hepatitis B, cirrhosis and liver cancer and demographic data during 1990 to 2007 in Shandong province. The incidence rate, mortality rate, age-specific and sex-specific incidence rate and age-specific mortality rate were calculated and statistically analyzed with the simple linear regression model, so as to analysis the epidemiological trend of hepatitis B, liver cirrhosis and liver cancer. For the elimination of phenomenon of cross-classification exist in the hepatitis B and liver cirrhosis mortality, hepatitis B and liver cirrhosis mortality will be analyzed in combination. At the same time to know about incidence trends of HBV in young age group since hepatitis B vaccine immunization for newborns.Based on the mortality data of hepatitis B, liver cirrhosis and liver cancer derived from the Third National Sampling Retrospective Survey for Causes of Death during 2004 and 2005, the prevalence and the disability weights of liver cancer gained from the Shandong Cancer Prevalence Sampling Survey in 2007, and the incidence data of hepatitis B and demographic data of Shandong province in 2005, we calculated the DALYs of three diseases.The mortality datas of hepatitis B were used to calculate the YLLs, and the incidence data of hepatitis and the disability weights and course of disease were used to calculate the YLDs. Based on the mortality data of liver cirrhosis we calculated the YLLs with the formula, and we used the indirect method to estimation the YLDs of liver cirrhosis. According to the classification of cirrhosis of the liver cause of death card, we calculate the DALYs of hepatitis B cirrhosis with the same method. The mortality datas of liver cancer were the data source for YLLs computing. The prevalence estimates, together with the disability weight data were used to calculate YLDs of liver cancer. The DALYs of liver cancer were due to HBV infection based on the proportion from the literature. Finally we calculate the total DALYs due to HBV infection.【Results】1. The total cases of hepatitis B were 437094, the yearly average morbidity was 27.32 per 100 000 population during 1990 to 2007. The incidence for men (38.42 per 100 000) was higher than that for women (15.83 per 100 000). The yearly incidence rates of hepatitis B were indicated an increase trend for the whole population, in which the 15-29 year-old had the biggest rise, while a decreased trend for the 0-9 year-old children in the past 18 years. It showed that the average age of onset was moved to the older.2. The downward trend of the mortality rates for hepatitis B had critical significance, but the adjusted mortality rates were shown a decreased tendency significantly; the crude mortality rates and adjusted mortality rates for liver cirrhosis were both shown a decreased tendency significantly; while the adjusted mortality rates for liver cancer had a steady tendency.The mortality for men was higher than that for women among the three diseases.3. The total burden for hepatitis B, liver cirrhosis and liver cancer were 211616 40457 and 309744 DALYs in 2005 in Shandong province, respectively. The burden of liver cancer was highest, hepatitis B second, and cirrhosis of the liver was relatively the lightest. The burden for hepatitis B was mainly because of disability (81.39%). However, the most of burden of liver cirrhosis and liver cancer was due to premature death (80.42% and 96.95%).4. The burden for hepatitis B, liver cirrhosis and liver cancer due to HBV infection were 211616 (39377 YLLs and 172239 YLDs),16783 (13497 YLLs and 3286 YLDs) and 247795 (240236 YLLs and 7559 YLDs) DALYs in 2005 in Shandong province, respectively. The total burden due to HBV infection were 476194 DALYs, indicating that 514.92 DALYs loss in every 100 000 population. The burdens for men were 2.19,2.36 and 3.16 times as that for women, respectively. The burden of each patient of hepatitis B, liver cirrhosis and liver cancer was 4.8,13.73 and 11.11 respectively. 5. The indirect economic burden of hepatitis B in 2005 was as high as RMB 29.49 billion, of which morbidity costs accounted for 83.96%. The indirect economic burden of liver cirrhosis was RMB 4.93 billion, of which mortality costs accounted for 79.72%. The indirect economic burden of liver cancer was RMB 34.90 billion, of which mortality costs accounted for 97.22%.【Conclusions】1. The trend of incidence of hepatitis B in the younger age group was significantly decline since China integrated hepatitis B vaccination into the national immunization program in 1992. The immunization of hepatitis B vaccine should be enhanced for other groups, especially for the high-risk population.2. Young adults of men are the focus groups for the onset of hepatitis B. We should improve the immunization coverage rate for this group.3. Hepatitis B, liver cirrhosis and liver cancer result in considerable burden to Shandong population. Controlling the hepatitis B virus infection has the huge potential benefits.