Infectious diseases have been in the news again. In recent days, schools and healthcare institutions have been affected by an illness caused by the Norwalk virus that leads to diarrhoea and vomiting. This has again highlighted the threat that infectious diseases continue to pose to public health, regardless of how modern our society is.

Our recent experience with the SARS epidemic was the greatest public health challenge faced by modern Hong Kong. It was an unprecedented outbreak of a disease that brought great suffering, fear and anxiety to all sections of our community.

Prior to the SARS outbreak, we had prided ourselves in having an efficient and effective healthcare system, one that provided affordable healthcare to all people of Hong Kong. We have even been able to bring under control, and within a short time, the first and subsequent human cases of avian flu when it first surfaced in 1997.

SARS challenged assumptions, beliefs

The SARS epidemic challenged our assumptions and tested our beliefs. It was a most humbling experience. The onset of the epidemic was rapid and its magnitude large.

Looking back, before the term "SARS" was coined by the World Health Organisation on March 15, more than 250 people had already been stricken with the disease. Before the SARS coronavirus was identified, the seed of infection had already spread to about 400 people.

Our lack of knowledge about this new disease and previously unknown virus, and the ferocity of the epidemic overwhelmed our healthcare system during the early stages of the outbreak.

Healthcare workers show dedication, resilience - courage

But this unprecedented threat to public health also starkly highlighted the remarkable courage, dedication and resilience of our healthcare workers. They demonstrated to their fellow citizens, and indeed to the rest of the world the highest form of professionalism.

We also learned that we had to synthesise and generate new knowledge and understanding on how the disease was spread and how to control it. We also had to adopt new approaches to public health if we were to win this battle against SARS.

For example, to cope with the tens of thousands of contacts of confirmed and suspected SARS patients, we had to devise a completely new e-SARS system for establishing and tracing the contacts of infected persons swiftly in order to protect public health. We combined this newly created online clinical database that stored and transferred SARS patients data, with an adapted Police criminal investigation system that can verify names and addresses of our targeted groups of people.

This innovative marriage of the two systems greatly helped in tracking down close contacts of SARS infected people as well as the implementation of other isolation measures. It also enabled the identification of potential problems in buildings which required remedial action in order to prevent the environmental spread of SARS. In fact, this use of technology proved to be an important reference model for many other cities in the global fight against SARS.

Community's cooperation, understanding key to winning SARS fight

The successful fight against SARS was also due to the co-operation and understanding of all people in Hong Kong, who sacrificed some of their personal freedoms to comply with the stringent measures such as temperature checks, a ban on hospital visits and home quarantine.

Overall, our efforts to control the spread of SARS in Hong Kong, and beyond our borders, was recognised by health experts and the international community. The WHO praised Hong Kong on a number of occasions for our openness and transparency in dealing with, and managing the epidemic.

The former director of the US Centre for Disease Control & Prevention Dr Jeffery Koplan once likened our public healthcare system to that of a dam wall protecting us from floods. For 50 years, it worked well. However, an unprecedented massive flood strikes and the wall is no longer able to serve its function. So, we need to build a higher wall. And that is what we are working hard to do now. Our strategy is to work on three fronts. They are: close surveillance, effective prevention, and swift control.

Three-pronged prevention strategy

To exercise close surveillance, we have stepped up liaison with our close neighbours, Guangdong and Macau. We have reached agreements with both places for a monthly exchange of data on 18 infectious diseases and immediate notification of any outbreak. New systems which bring early alerts of potential outbreaks have also been developed.

For effective prevention, we continue with temperature and health checks at boundary control points. We have compiled a detailed list of measures to prevent and combat SARS, if it returns. Seventeen sectors in the community including hospitals, public transport operators, schools, elderly homes have worked with us to develop these enhanced disease prevention measures.

To prepare for efficient and comprehensive contact tracing work, Department of Health staff have joined a number of overseas training courses to upgrade their knowledge in infection control, surveillance and case identification.

To set up a framework for swift and effective control in case of a resurgence of SARS, we have put in place a government-wide contingency plan with a clear command structure if there is a new SARS case.

Infection-control measures stepped up

Our public hospitals are now equipped with enhanced infection-control facilities, and 900 new isolation beds, and 600 will be put into operation early next year. To provide better protection for healthcare professionals, the Hospital Authority now keeps a three-month contingency stock of protective gear.

Intensive training courses in infection control have been given to hospital staff. Alerting, isolation, management of suspected patients and, in particular, infection-control measures in hospitals have also been improved. The government has allocated $450 million to set up a fund for research projects on infectious diseases and health services.

In the longer term, we will set up a Centre for Health Protection in Hong Kong. The centre will conduct comprehensive public health surveillance on communicable diseases, develop strategies for the effective control of communicable diseases, develop and review contingency plans to respond effectively to communicable diseases and build capacity and develop professional expertise.

When the centre is up and running, I am confident that our surveillance capacity for communicable diseases, including new and emerging infectious diseases, will be much strengthened.

Personal, environmental hygiene key to prevention

However, infectious diseases such as SARS and the Norwalk virus cannot be stemmed by relying solely on the healthcare system and medical technology. Personal and environmental hygiene are also of paramount importance.

All of us have to play our part in protecting our own health as well as the health of the community. In observing strict hygiene practice at personal, domestic and community levels, we can help build a cleaner living environment and prevent the spread of infectious disease in the future.

Hong Kong is now approaching the peak season for 'flu' and other viral illnesses. There is a possibility that SARS may rear its ugly head again. But if we remain vigilant and prepared, if we pay extra special care to our personal hygiene, then we can greatly reduce the chances of another outbreak.

Secretary for Health, Welfare & Food Dr Yeoh Eng-kiong gave this address on "Letter to Hong Kong" on RTHK Radio 3.