Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are two of the most common chronic liver diseases worldwide, and results in a significant health burden. While liver diseases are common in Hong Kong, there has been no recent representative survey on the prevalence of viral hepatitis in our region.
The research team of Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong (HKUMed), performed a territory-wide study involving 10,256 individuals on the prevalence of viral hepatitis, including hepatitis A virus (HAV), HBV, HCV and hepatitis E virus (HEV). The study identified areas of need in combating liver diseases and in improving liver-related health in Hong Kong.
The World Health Organization 2030 Objectives on Viral Hepatitis
In 2016, the World Health Organization (WHO) set the global objective in eliminating viral hepatitis, mainly HBV and HCV, as a public health threat by 2030. This included achieving a diagnostic coverage of 90%, a treatment coverage of 80% among eligible patients, and a reduction of 90% and 65% in new infections and liver-related death, respectively. Based on its 2017 report, the global diagnosis and treatment coverage of HBV was only 9% and 8%, respectively, signifying much public health efforts are still needed.
Liver disease is common in Hong Kong, with HBV being the major cause. Prior to the availability of universal HBV vaccination in 1988, the major route of HBV transmission was mother-to-child during or just after childbirth. HBV can also be transmitted through blood and body fluids, for example through sharing of contaminated needles and sexual contact. Patients who are infected with HBV can become chronic carriers. As most HBV carriers are asymptomatic, most patients are not diagnosed until hepatitis B develops into cirrhosis and liver cancer. Liver cancer is a deadly cancer, its mortality rates are ranked 3rd in male and 4th in female. 1,540 patients died of liver cancer in Hong Kong in 2016.
The HKU research team collaborated with the Hong Kong Liver Foundation, a non-government organization dedicated in combating liver diseases in Hong Kong. From 2015 to 2016, our team visited all 18 Hong Kong districts, giving health promotion lectures and offering free blood testing for HAV, HBV, HCV and HEV in participants aged 18 years or above. Participants have to also fill in a 2-page questionnaire on their socioeconomic and medical background. Those who were tested positive for HBV or HCV were provided a referral letter to specialist care.
This study recruited 10,256 individuals over a period of 19 months. The mean age in male and female participants was 50.4 years and 52.3 years, respectively. Participants came from all 18 Hong Kong districts, especially Yuen Long (10.8%), Hong Kong East District (10.7%) and Kwun Tong (10.4%).
The overall prevalence of HBV in Hong Kong was 7.8% (male 8.8%, female 7.3%). Very importantly, 48% of HBV-infected participants were unaware of their HBV status prior to this study. The prevalence of HBV was 8.3% among Hong Kong-born participants prior to the availability of universal HBV vaccination. Among those born after commencement of universal vaccination, the prevalence was still 1.8%. HCV was uncommon in Hong Kong, with a prevalence of 0.3%.
HAV and HEV are usually acute self-limiting infections with no long-term sequelae. 65.1% and 33.3% had antibodies to HAV and HEV, respectively, a significant increase from a previous survey in 2001. HAV and HEV antibodies were more common in participants with a lower family income.
Significance of the study and suggestions
With this first largest population territory-based study done in Hong Kong, HKU team confirms HBV remains a common disease in Hong Kong as well as the effectiveness of universal HBV vaccination. As almost half of patients with HBV were unaware of their disease status, the study results urgently call for raising public awareness and screening on HBV, especially if Hong Kong is to achieve the public health objectives of WHO in 2030.
“To achieve the WHO 2030 goal, implementation of whole-population screening for HBV is necessary. A comprehensive health care strategy is required for the whole of Hong Kong if we are to improve diagnosis and treatment coverage and reduce the risk of liver cirrhosis and cancer.” says Professor Richard Yuen Man-fung, Chair Professor of Gastroenterology and Hepatology of Department of Medicine, Li Shu Fan Medical Foundation Professor in Medicine, HKUMed.
About the research team
Professor Richard Yuen Man-fung, Chair Professor of Gastroenterology and Hepatology of Department of Medicine, Li Shu Fan Medical Foundation Professor in Medicine, and Dr Walter Seto Wai-kay, Clinical Associate Professor of Department of Medicine, HKUMed have been conducting HBV and liver research for many years. A number of observational and interventional research projects are currently in progress, which will eventually provide more research insights and be of benefit to the Hong Kong community.
Professor Richard Yuen Man-fung (left) and Dr Walter Seto Wai-kay (right).
With the first largest population territory-based study done in Hong Kong, HKU team confirms HBV remains a common disease in Hong Kong. The study results urgently call for raising public awareness and screening on HBV, especially if Hong Kong is to achieve the public health objectives of WHO in 2030.
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