According to the World Health Organization, viral hepatitis makes a substantial contribution to the burden of chronic diseases. Infections with hepatitis B and C viruses cause an estimated 57% of cases of liver cirrhosis and 78% of cases of primary liver cancer worldwide annually (
16).
This study estimated rates ranging between 36.4 and 53.6 DALY/100000 people. In Spain, the estimated rates were 20.4 DALY/100000 people (
8) and in Germany, 9.4 DALY/100000 people (
9). Substantially higher rates found in the state of Santa Catarina indicate the need for intensified prevention and surveillance. Particularly, the west region of Santa Catarina is considered an endemic area for hepatitis B (
3), which certainly contributes to increase the studied indicators.
In the time-series analysis, significant declines were observed in YLD and DALY rates, which may represent better public policies and care in the treatment and prevention of new cases of hepatitis B in the state of Santa Catarina. On the other hand, increased YLL rates were observed, especially among men and in older age groups that may represent advanced cases of disease (cases of liver cirrhosis or hepatocellular carcinoma) that may represent late diagnosis, which reinforces the need for population-based serological screening and enhancing immunoprophylaxis of hepatitis B in males and the elderly.
A study of trends in the hepatitis B incidence in the state of Santa Catarina showed a 5.9% increase in incidence rates from 2002 to 2006, and a significant drop of 6.4% from 2006 to 2009 (
4). Although neither the above-mentioned study nor the current one has a method approach with an explanatory design; it can be hypothesized that reduction in rates may be a reflection of immunization programs and surveillance activities aimed at prevention. This can also be seen in the analysis by age group, since there are few cases among children and adolescents. This could be attributed to the vaccination campaign that began in 1992 in the state of Santa Catarina for children under five and presented 98.8% coverage rate during 2005 and 2010 (
17). Furthermore, the increase found in the YLL rates could evidence improvements in health information systems in Brazil (
18).
The male usually has a higher prevalence of HBV infection (
2,
19,
20) possibly due to occupational exposure, drug use and promiscuous habits compared to women. In addition, the vaccine schedule was initially aimed to reduce mother to child transmission. The present study showed a significant increase in men’s mortality burden, which can indicate that they may not have access to early diagnosis and treatment in a timely manner. This situation highlights the necessity for effective prevention policies aimed at men’s health. Regarding disability, there was a significant decrease among women, a phenomenon occurred in DALY rates as well. Similar results were found in Spain in both early mortality and disability components (
8). A study conducted in the Canadian province of Ontario found that the impact on the burden of hepatitis B was higher among men than women (
10). The present study demonstrated that DALY rates had a significant increase in the 70-79 age range during the study period. These figures highlight the necessity for preventive actions aimed at elderly people, such as expansion of vaccination against hepatitis B for all age groups and campaigns that encourage immunization, since Brazil does not provide hepatitis B vaccination for elderly populations, except in high-risk groups. There is no record in the Brazilian database of hepatitis B vaccination for this age group (
21,
22). The Brazilian national immunization program provides the vaccination against hepatitis B for people younger than 50 years. The vaccine was gradually introduced nationally since 1989 due to the high prevalence in the western Amazon region. The Brazilian Ministry of Health guidelines state that vaccination against hepatitis B should be guaranteed primarily to high-risk groups, even if they are outside the age range and to every individual above 50 years who seek vaccination against hepatitis B (
22). In some European countries, especially in the south of the continent, the burden of chronic liver disease due to hepatitis B is increasing because of the unvaccinated aging population (
21). A study conducted in China showed an increased burden of liver cancer in patients with an average age of 55 years, due to hepatitis B (
7).
Hepatitis B is considered a global problem with high incidence in different countries, including Brazil. Thus, taking preventive measures to control viral hepatitis is of utmost importance. Vaccination against hepatitis B is safe and effective. In many countries where 8% to 15% of children used to become chronically infected with hepatitis B virus, vaccination reduced the rate of chronic infection to less than 1% among immunized children (
23). Some measures recommended by the World Health Organization tend to change the current scenario of hepatitis B. These actions include increased resource mobilization for disease prevention, with efforts to improve vaccination coverage, actions to prevent transmission of the virus, guidelines for screening, diagnosis and treatment of the disease and purposeful actions to reduce treatment costs (
16).
Brazilian national public policies encompass vaccination of healthcare workers, safety of injections using disposable syringes and needles in all health services, rigorous screening of all donated blood, prevention of viral hepatitis among drug users and referral network for patients with viral hepatitis (
23). These policies help reduce the overall rates of hepatitis B in the country and can show a decline in the disease rates in the coming years (
23).
Limitations of this study include possible underreporting of hepatitis B cases, considering the long-term asymptomatic phase and underreporting of cases in SINAN and registration of SIM deaths due to undetermined causes. An example is seroepidemiologic population surveys or in groups with greater vulnerability with high rates of HBV infection (
24-
27). Therefore, the findings should be interpreted with caution, since underreporting of cases can interfere with disease burden presented in this study.
There is an urgent need to raise awareness of healthcare workers to investigate and report all cases of hepatitis B. This measure would allow access to more comprehensive data about the disease, and can help plan actions to improve early diagnosis and treatment of the disease. Moreover, considering the natural history of the disease, it is estimated that only cases with greater severity and presence of signs and symptoms are investigated and reported.
A significant decrease in the burden of hepatitis B rates and disability components in the state of Santa Catarina between 2005 and 2010 was observed. However, there was a significant increase in the early mortality component rate in the same period.