Professor Sian Griffiths

When I received the phone call inviting me to be part of the Hong Kong government's group of international experts to review SARS, I accepted immediately - not really knowing what it entailed except a better chance to understand the story of a disease which had rocked the world - with Hong Kong at its epicentre. I had no idea of the time it would take, the wonderful people I would meet, the piles of paper I would read or the drama in which the review team would play a role.

The Story of SARS

The story of SARS in Hong Kong reads like a detective novel. It was winter and the authorities in Hong Kong were expecting an outbreak of infectious disease. There were fears about avian flu and a case was confirmed in February. Every winter there are around 2000 cases of pneumonia each month. Was this year going to be different? In early February rumours about cases of a new disease in Guangdong, across the border in Mainland China, were picked up by the clinical community. In mid-February the media reported stories of panic buying of white vinegar in Hong Kong from across the border as well as a run on herbal medicine good for boosting the immune response particularly in cases of pneumonia. Initial attempts by Hong Kong's Director of Health to find out what was going on from the Guangdong authorities elicited no response until the next day when information was made known in a bulletin from Guangdong about an atypical pneumonia which affected healthcare workers. This was the first formal indication to Hong Kong that they too might have cases - particularly since around 300,000 people cross the border between Hong Kong and southern China everyday and much of the food for Hong Kong's 6.5 million population is produced in Guangdong.

The community was alert but not sure what it was waiting for. The first events to cause concern occurred at the Prince of Wales hospital - the teaching hospital for the Chinese university. On Monday March 10th eleven healthcare workers reported sick. By that evening it was 50.They had a mixed pattern of clinical symptoms including fever and cough but the causative agent was not known. The disease continued to spread to healthcare workers, their families and contacts.

Within a few days the index case was identified as an airport worker admitted with atypical pneumonia to ward 8A of the Prince of Wales Hospital (PWH). Contact tracing showed that medical students and other clinical staff who had examined and cared for this patient were more likely to have become infected - particularly after he had been put on nebuliser treatment. In addition some of his relatives were also admitted later that week. In all 143 individuals were found to have become infected through contact with this patient, including 50 healthcare workers and 17 medical students.

In tracing back to where the index case had acquired the infection a link with hotel Metropole in Kowloon was discovered. Hotel Metropole was where a Professor visiting from Guangdong was staying before he was admitted into the infectious diseases hospital on February 22nd. Piecing the story together through the surveillance system the Department of Health (DH) were able to identify Hotel Metropole as the source of the spread not only through Hong Kong but also internationally, providing a link to Singapore, Canada, Vietnam and Taiwan (see diagram).
The epidemic at the PWH spread into the community despite best efforts to control spread of infection. One of the patients to become infected was linked to the outbreak on the Amoy gardens estate.

On the 26th of March the DH were notified about 15 suspected cases of SARS from seven households from the Amoy gardens admitted with respiratory symptoms to the nearby United Christian hospital. A new pattern of disease was emerging - many of the cases also had watery diarrhoea. The public health team went into action - contact tracing and instituting environmental control measures. The public were briefed to be vigilant using the media who are very active in Hong Kong and also through local residents associations and healthcare staff. By now most people were wearing masks and the community was very scared.

By the 30th of March it was obvious that this was a major epidemic of potentially devastating scale. On the 31st the residents of Block E - the most affected block - were put into isolation by quarantining their block. When new information about a potential environmental source was made known to the government that same evening, the decision was made to move the residents to a holiday camp. At 6am on April 1st all residents were asked to pack a few things and to move. To everyone's credit this move went smoothly, 247 residents were evacuated and it was arguably this step that contained the epidemic. Within the next few days the majority of residents who had already left the building were also traced.

The distribution of cases between the blocks showed that the infection was contained in one part of the estate - with 49% of the cases in Block E. Environmental disinfection of public areas and measures to contain environmental spread were under the control of a cross government group who had far reaching powers to ensure that all that needed to be done could be done. Schools were closed, public places disinfected, contacts traced and the public advised to wear masks and to take note of basic personal hygiene practice. The old adage coughs and sneezes spread diseases needed to be taken seriously.

The evacuation of the residents contributed to the control of the epidemic, and the number of daily cases began to drop (see graph).

But why Amoy Gardens? The source of infection can be traced back to a patient who lived in Shenzhen across the border in Guangdong but was having renal dialysis at the PWH. He had stayed with his brother overnight on March 4th - and had been admitted during dialysis treatment with a chest infection. He responded to treatment, was afebrile and his chest x-ray was clear so he was discharged. He stayed with his brother again on March 21st, and when he attended for dialysis on March 22nd was readmitted, this time with SARS. His brother lived in block E, where the majority of cases also lived. One of the patient's symptoms was watery diarrhoea. Subsequently it was found that 73% of cases from Amoy gardens had watery diarrhoea as reported in the Lancet: diarrhoea seemed more prominent than previously reported and the severe watery diarrhoea in these patients presented a challenge to healthcare workers for infection control.

But why were so many people affected? Factors thought to have contributed to the epidemic include:

• Dried up U traps- underfloor water traps, filled through a grid , normally providing a seal between the bathroom and the soil stack
• A break in the flush water pipe serving all Unit 8 of Block E, which led to the flushwater system being shut down overnight - this could have decreased the flow and increased movement of droplets in the soil stack, contributing to spread
• Exhaust fan causing droplet spread

Hypotheses are still being developed. There has even been speculation about rats and cockroaches, as yet unfounded, as well as questions about building design. Meanwhile the government has increased its efforts to promote environmental hygiene as well as personal hygiene.

The final phase of the SARS epidemic produced yet another problem - atypical presentation. The typical presentation of SARS is of fever, respiratory symptoms, and chest x-ray changes of pneumonia. However, a proportion are 'cryptic' cases presenting in other ways and not all with fever. This is particularly common in older patients who have co-morbidity and in immuno-compromised patients. The symptoms may well be masked by treatment for another disease. This raised particular issues for the care of the elderly particularly those in institutions. Special efforts were made to provide support and advice to elderly care homes that in many instances in Hong Kong are part of other high rise buildings. By the beginning of May numbers of daily cases had dropped to below 10, and by mid-May to under five a day.

The travel advisory ban was lifted by the WHO on May 23rd and all restrictions lifted on June 23rd. The epidemic had claimed 300 lives and affected 1755 people. 20% of the cases were in healthcare workers, and 20% amongst elderly patients. 63% of the deaths were amongst these older people.

What did our Report Point Out?

Firstly we expressed our sympathies for those who had died. We expressed our admiration for the healthcare workers and others who continued to treat patients and tackle the disease, putting themselves at risk. Many of the things they did were exemplary - not least the development of a system-wide information system, eSARS, which allowed contact tracing utilising the police database, the identification of the atypical coronavirus by March 23rd and the successful evacuation of Block E of Amoy Gardens.

But there are many lessons to be learnt. Our main objective was to analyse what took place - taking care to do this from the perspective of what was known at the time that events were unfolding. Our report highlights the failings we found in the healthcare system, particularly those at the beginning of the epidemic. For instance, if there had been better communication between Guangdong and Hong Kong about infectious diseases then Hong Kong would have been alerted earlier. If there had been better infection control measures and outbreak control planning then the disease might not have spread so quickly in the beginning. If there had been better mechanisms for communication then the confusion and accusations about active suppression of information by government would have been avoided. If there had been a more comprehensive epidemiological study of Amoy Gardens then the understanding of the disease would have been enhanced. Better collaboration across all elements of the healthcare system - with private GPs, community clinics and old people's homes - would have enhanced surveillance.

But all this needs to be put against a background of a very impressive response by the whole community in Hong Kong and we were impressed by the speed with which initial lessons were learnt and the response improved.

Overall, we concluded that there had been problems in the handling of the outbreak and we made a series of 46 recommendations which, if implemented would, we believe, make a difference to handling of a future epidemic. These recommendations can be grouped under three main headings:
o Organisation and structure - particularly of the healthcare system and its health protection functions
o Collaboration, co-ordination and communication - particularly the need to work across the Pearl River delta since infectious disease is no respecter of international boundaries, and also the need for better media relations
o Management of epidemics - including training, clinical practice, research, surveillance and surge capacity. Under this section we made proposals for more emphasis on infection control training for all staff as well as strengthening infectious diseases and public health as options for clinical training. We proposed a cadre of epidemiologists who would work across all sectors- hospital, community, university, department of health - who would break down some of the silo thinking which got in the way of handling the SARS epidemic.

We were also particularly concerned about the longer term effects of SARS not only on those who had had the disease but on the community as a whole. One of the features of the epidemic had been the discrimination by some against those who had the disease, or who were in contact with it. This was demonstrated by some people losing their jobs because they became infected. We recommended further research and also active support through a contingency fund.

All our recommendations were accepted by the government. However, the press did not give our report a very warm reception. The headline from the South China Morning Post- was "SARS panel finds fault but not blame". This was likely to be due to a variety of reasons - including debate about Article 23, the unpopularity of the government, the widespread belief that someone must be to blame. The criticism was reflected by the president of the Medical Association, who also chairs the legislative council's health committee, who said "the report has failed to fully address the issue of political accountability and government responsibility". He has gone on to lead the establishment of a further committee in order to find blame.

As authors of the report we disagree with him. We believe that no individual was to blame and that Hong Kong responded well to SARS overall. The important thing is to get on with establishing the Centre for Health Protection and other recommendations so that, if SARS comes back, Hong Kong, on behalf of the rest of the world, will be better prepared.

Further Information

Report of the SARS Expert Committee. SARS in Hong Kong: from Experience to Action. www.sars-expertcom.gov.hk 2003.

Professor Sian Griffiths, OBE is Senior Fellow in public health at Oxford University