Apasl Commemorative International Congress On Viral Hepatitis, Prevention And Control

16 Feb 2000

By Mr Lim Hng Kiang

Theme :

Prevention and Control of Viral Hepatitis - Past Achievements and New Challenges

Distinguished guests, ladies and gentlemen

INTRODUCTION

Let me first extend a very warm welcome to all the Delegates and distinguished Faculty. This Congress is a significant event as it brings together experts from all over the world to meet and review past achievements and to discuss emerging problems and new research findings in the prevention and control of viral hepatitis.

Viral hepatitis is one of the most common infectious diseases in the world. It is a major public health problem worldwide. Among the many types of viral hepatitis, hepatitis B infection is a major cause of illness and death. About 350 million worldwide are chronic carriers. WHO has estimated that hepatitis B infection alone causes more than 1 million deaths every year worldwide.

The significance of hepatitis B lies in the large number of carriers of the disease and its association eventually with the development of serious liver disease including chronic hepatitis, cirrhosis and liver cancer. Liver cancer is among the ten most important cancers in the world, and is common in South East Asia, the Western Pacific regions and sub-Saharan Africa.

The most effective strategy to control hepatitis B infection is through hepatitis B vaccination. Hepatitis B vaccines have been available for about 2 decades. Over the years, newer and cheaper vaccines have made it possible for many countries to incorporate hepatitis vaccination into their National Immunisation Programme. But unfortunately, there are many people world-wide who still remain unprotected. For the infected, screening methods are now available in detecting the carrier state. However, in many parts of the world, screening facilities are not easily available or accessible. In addition, as treatment for hepatitis B carrier is still not very satisfactory, more research needs to be done to develop more cost-effective drugs to treat chronic carriers to prevent them from developing into liver cancer.

Hepatitis C infection is another important type of viral hepatitis as its carriers are also at risk of developing chronic liver disease and cancer. An estimated 3% of the world population is infected with hepatitis C and around 170 million are chronic carriers. Hepatitis C has been identified to be related to blood transfusion. About 90% of post-transfusion hepatitis in Japan, USA and Western Europe are caused by this virus. Unlike hepatitis B, there is as yet no vaccine against hepatitis C.

HEPATITIS IN SINGAPORE

Viral hepatitis has been recognised as a disease of major public health importance in Singapore since the early 1970s. Viral hepatitis became a notifiable disease in 1977 and specific control measures were implemented. Let me give an account of our experience.

Hepatitis A

Hepatitis A was common in Singapore in the 1970s. Over the past 3 decades, we have raised the standards of environmental hygiene and sanitation, improved housing conditions and implemented an effective public health education programme directed at food-borne diseases. The incidence has declined dramatically. In recent years, the majority of patients with hepatitis A infection acquired the disease overseas. Today, individuals and the discerning traveller can protect himself from hepatitis A infection with vaccination.

Hepatitis B

Hepatitis B is the other viral hepatitis of public health importance in Singapore. Recognising this, my Ministry implemented the hepatitis B prevention and control programme in the early 1980s. The key component of the programme is based on immunisation to prevent infection by carriers of the susceptible population. The other components of the programme are surveillance, infection control precautions, screening of all blood donors and public education. The main strategy of the hepatitis B immunisation programme is to immunise all infants and young children as early in life as possible to prevent infection. Since 1987, Hepatitis B vaccination has been fully integrated into our national childhood immunisation programme. Today, the coverage for hepatitis B immunisation in infants is more than 90%.

With the implementation of the control measures, the incidence of acute hepatitis B infection has declined by 60%, from 10 per 100,000 population in 1985 to 4 per 100,000 population in 1999. The incidence rate of primary liver cancer among males has also declined from 29 per 100,000 per year during the period 1968-1972 to 19 per 100,000 in 1993-1997.

Over the years, my Ministry has also supported active research on viral hepatitis. As early as 1976, a study group was formed to collect, review and evaluate important local epidemiological data on hepatitis, liver cancer and its complications. In 1985, a National Reference Centre at the then University Department of Medicine in the Singapore General Hospital was recognised by the World Health Organisation as one of the ten global centres for the evaluation of hepatitis B vaccines. Our researchers and scientists have since evaluated the safety and efficacy of hepatitis B vaccines and carried out studies on the other newer forms of viral hepatitis. Research is continuing in the detection and identification of new strains of hepatitis and how these relate to human disease, new diagnostic methods and the testing of anti-viral agents.

Hepatitis C

Hepatitis C infection is uncommon in Singapore. There have been no reported cases since 1993. As hepatitis C is transmitted mainly through blood, my Ministry has, as far back as 1992, implemented routine screening of all blood donors for hepatitis C. Health care workers also practise strict infection control measures to minimise the risk of transmission in the health care setting.

NEW CHALLENGES

There are emerging problems, challenges and new developments that lie ahead in the fight against viral hepatitis. There is the potential threat posed by new viruses. Future developments in diagnostic technologies and therapies will need to include more accurate tests to detect the viruses and more effective anti-viral drugs for the treatment of the infections and prevention of long term complications. Our local researchers have done well over the last few decades to prevent, and control viral hepatitis in Singapore. I hope that they will continue to contribute in the global effort to search for better diagnostic methods and more effective therapies.

CONCLUSION

I congratulate the Asian Pacific Association for the Study of the Liver and the Academy of Medicine, Singapore for organising this Congress. I am sure you will have a stimulating and fruitful meeting over the next few days. I wish you success in your endeavours to prevent and control hepatitis and liver cancer. It is my pleasure now to declare the Congress open.