An estimated 576,000 people are living with hepatitis B in Hong Kong, according to a study carried out by Department of Medicine researchers at the University of Hong Kong (HKU).
The team, led by Professor Yuen Man Fung (Croucher Fellowship 1997) in collaboration with the Hong Kong Liver Foundation, conducted a city-wide survey over 19 months between 2015-16 and found a high prevalence of hepatitis B in the population. The finding points to a lack of public awareness and need for early detection of the disease. The researchers also identified areas of need in combating liver diseases in Hong Kong.
Of the 10,256 individuals who underwent a blood test for the survey, 7.8 per cent (8.8 per cent in males, 7.3 per cent in females) tested positive for hepatitis B virus (HBV). While only 0.3 per cent were found to be infected with hepatitis C virus (HCV), 65.1 per cent and 33.3 per cent had antibodies to hepatitis A virus (HAV) and hepatitis E virus (HEV) respectively, a significant increase from a survey conducted in 2001.
“We set out to document the total number of hepatitis cases in Hong Kong so that professionals can better design future healthcare packages for this group of patients,” said Yuen. “As the biggest survey ever conducted in the region, our results reflect the actual on-the-ground situation. Hepatitis B is a significant public health problem that afflicts a large number of people in Hong Kong so we urge the government to work on it before it is too late.”
An estimated 257 million people worldwide were living with hepatitis B in 2015, but only 9 per cent knew of their diagnosis, according to the World Health Organization (WHO). Most people do not experience any symptoms during the acute infection phase. As they are unaware of their status, they aggravate the problem by transmitting the disease, as indicated by the fact that 48 per cent of those diagnosed during the HKU study were previously uninformed of their condition. Hepatitis B was responsible for 887,000 deaths globally in 2015.
“This clearly points to a lack of education on the part of the public so creating awareness was a big part of our survey,” said Yuen, adding that the increase in HEV meant people in Hong Kong are still unaware of risks of eating raw pork and internal organs such as liver. “During site visits to all 18 districts in the city, we conducted seminars to inform people about the disease, its prevention, and treatment.”
Once hepatitis B infection chronicity is established (usually during early childhood), the virus would remain in the body for life. 30 per cent of cases left untreated may cause complications, such as liver cancer and cirrhosis, later in life. In fact, hepatitis B is related to 80 per cent of all liver cancer cases in Hong Kong. Hepatitis C accounts for an additional five per cent.
Apart from the high risk of death, complications arising from chronic hepatitis B are expensive to manage and treat, hence prevention and early diagnosis are cost-effective and crucial. Early treatment has shown the incidence of liver cancer and cirrhosis drops significantly.
A hepatitis B vaccine has been available since 1982. A combined vaccine providing active immunity against both hepatitis A and B is now widely obtainable.
The high prevalence of HBV in Hong Kong makes it important to screen everyone, Yuen said. Once carriers are identified, they should be brought into the healthcare system for continuous monitoring and appropriate treatment, he noted.
To meet WHO targets to eliminate hepatitis B and C as public health issues, that is, a 90 per cent reduction in new chronic infections and 65 per cent reduction in mortality by 2030, Hong Kong will need early detection and preventative measures.
Yuen’s team is now working on a follow-up survey to check whether individuals who tested positive for HBV or HCV in the first study have been enrolled into the healthcare system following the referral provided to them and, if not, to explore the constraints preventing them from doing so.
Professor Man-Fung Yuen is the Chair Professor and Endowed Professor in Medicine of the Li Shu Fan Medical Foundation, the Chief of the Division of Gastroenterology and Hepatology and the Deputy Head of the Department of Medicine, Queen Mary Hospital, Hong Kong. Professor Yuen’s research interests include the prevention, natural history, molecular virology and treatment of chronic hepatitis B and C, and hepatocellular carcinoma. He is the top 1% scientists in clinical medicine according to the ISI Web of Knowledge. Professor Yuen received Senior Medical Research Fellowship in 2020 and the Croucher Fellowship in 1997.
- Prof. Yuen’s personal page (Croucher Foundation): https://scholars.croucher.org.hk/scholars/yuen-man-fung
- Prof. Yuen’s personal page (The University of Hong Kong): https://medic.hku.hk/en/Staff/University-Academic-Staff/Prof-YUEN-Man-Fung/Prof-YUEN-Man-Fung-profile
- WHO’s fact sheets of Hepatitis B: https://www.who.int/news-room/fact-sheets/detail/hepatitis-b