Statement From The Minister For Health: Coping With Sars

04 Apr 2003

By Mr Lim Hng Kiang

Introduction

Just one month ago, Severe Acute Respiratory Syndrome or SARS was not even in the medical vocabulary. Today, Singaporeans are concerned and anxious about the spread of this new disease and how it would affect their health and that of their family.

How it all started, 6 - 15 March 2003

On 6 March, WHO alerted MOH that several hospital staff in the French Hospital in Hanoi had developed an unusual respiratory illness after treating an American patient who had severe pneumonia. Our hospitals had identified three Singapore patients who had developed atypical pneumonia. Nothing was known about SARS then. However, MOH instructed the hospitals to isolate the patients and to take all the necessary infection control precautions.

We also started contact tracing investigations of the three cases and found out that they had all stayed in the same hotel in Hong Kong. TTSH and SGH carried out various laboratory investigations to try to determine the cause of the pneumonia in the three patients. However, no definite cause could be found.

On 12 March, it was reported that the hospital in Hanoi had closed after 16 of its staff contracted an unidentified illness after an American patient was treated there for severe atypical pneumonia. On the same day, the Department of Health in Hong Kong issued a press release that some staff at the Prince of Wales hospital had developed an unusual respiratory illness. WHO issued a global alert about cases of a severe form of atypical pneumonia in Hong Kong and Vietnam that particularly affected hospital staff.

On 15 March, WHO coined the term Severe Acute Respiratory Syndrome (SARS) for the new disease and initiated enhanced global surveillance for the disease.

Current state of knowledge on SARS

SARS is a new form of infection which has been recognised for less than a month. We have learnt much about the characteristics of this illness over the past month but there is much that is still not known.

Firstly, the cause of the infection has not been found. However, both the WHO and the US Centres for Disease Control (CDC) have reported that the infection is likely to be due to a virus from the coronavirus family. Some coronaviruses are known to cause the common cold in humans. However the virus associated with SARS is unlike any known human or animal member of this virus family. So, it is likely to be a new type of coronavirus.

Not knowing the exact virus responsible for SARS means that we still do not have a test which we can use to diagnose if patients are suffering from SARS. We also do not know the specific properties and behaviour of the virus when they affect humans. However, we can draw upon some information that is known about members of the coronavirus family in general. For example, it is known that some strains of the coronaviruses can survive in the environment for up to three hours.

Secondly, we know the incubation period of SARS. WHO and the US CDC have both stated that the incubation period ranges between 2 and 10 days. In the majority of cases, the incubation period ranges from 3 to 7 days.

This information helps us in our contact tracing investigations and in deciding on the period of quarantine for close contacts.

Thirdly, we have a good idea of how the disease develops from our local experience of more than 90 cases so far, and the experience reported by others in the rest of the world. The earliest symptom is a sudden onset of high fever with or without muscle aches. Some patients may also have chills, shivering, cough and headache. After 3 to 7 days, patients may start to have cough and shortness of breath, and X-ray changes of pneumonia, usually after a further 3 to 4 days. In about 80 to 90% of cases, the patient gradually recovers. However, in 10 to 15% of cases, the pneumonia progresses and the patient needs treatment in the intensive care unit with most requiring a ventilator to help them breathe. About 4 to 5% of cases die despite intensive care.

Fourthly, the consensus among the medical community and reflected by the WHO and the US CDC is that persons are most likely to be infectious when they have symptoms, such as fever and cough. From our own experience, it also appears that persons are more infectious when they become more ill. Most of the SARS patients in Singapore have passed on the infection to a small number of people only, and through close contact. However, we have also noted that there are a small number of SARS patients who appear to be highly infectious, infecting a large number of people (super-spreaders). Hence, 3 SARS patients have been responsible for the transmission of the infection to 91 non-imported patients that we have seen so far.

What does this tell us about how SARS can be transmitted? Both WHO and the US CDC believe at present that the main way SARS appears to be spread is through droplet transmission, for example, when a SARS patient coughs or sneezes droplets into the air and someone else breathes these droplets in. Our own experience in Singapore supports this view since almost all of our cases have occurred either among healthcare workers caring for SARS patients in hospital, or family members and friends of the patients who had visited and come into close contact with them.

At present, the bulk of the evidence is that there is little airborne transmission of the infection. Airborne transmission means that the viral particles remain suspended in the air for prolonged periods of time and therefore can infect far greater numbers of people at greater distances. For example, people can get infected by just being in the same room or same plane as an infected person. This has not been the case so far. WHO has stated that thousands of passengers who travelled on the same flights as persons ill with SARS have been traced in Germany, Canada, Singapore and the United States but no cases of SARS had been found among them. This would not be the case if SARS spreads by airborne transmission. We know only of one flight crew who developed SARS and she was an air stewardess who had attended to a person who had SARS on board the flight.

However, we cannot exclude the possibility that there may be some situations where SARS is much more infectious, perhaps through other routes of transmission. For example, the reports on 31 March, of a large number of residents becoming affected by SARS in an apartment block in Hong Kong and the infection of several visitors staying in the Metropole Hotel in Hong Kong suggest that SARS may be transmitted more broadly, perhaps through some common environmental route.

There is as yet, no specific treatment for SARS. WHO has stated that no treatment beyond good intensive and supportive care has been shown to improve the outcome in patients with SARS. With good supportive and intensive care, 80 to 90% of patients with SARS will recover without any complications. Unfortunately, about 4 to 5 % will die despite good intensive care. Treatment with serum from patients who have recovered is still being evaluated.

SARS - the current global situation

I would like to turn now to the overall SARS situation. As of 2 Apr 2003, WHO has reported that SARS has spread to 17 countries.

Due to international travel, SARS can spread quickly to more countries. Even after a country has controlled its local outbreak, a new one can start again from imported cases. In Singapore, 91 cases can be traced to the three original index cases over four generations of infections. In Canada, the 56 cases in Ontario has been traced back to an index case who had travelled to Hong Kong.

According to WHO, the SARS situation in Hong Kong has developed features of concern: a continuing and significant increase in cases with indications that SARS has spread beyond the initial focus in hospitals. There is also the possibility that some transmission in Hong Kong is occurring through some environmental route that links rooms or flats together. Despite the implementation of strict measures to control the outbreak, a small number of visitors to Hong Kong have been identified as SARS cases after their return from Hong Kong. The epidemic in Guangdong province is the largest outbreak of SARS reported and has also shown evidence of spread in the wider community. This has prompted the World Health Organisation to issue an unusual travel advisory for persons to postpone all non-essential travel to Hong Kong and the adjacent Guangdong province.

Regarding Vietnam, WHO has said that the number of cases (58) and deaths (4) has remained stable for nine days in a row. However 1 new case has been reported yesterday. On Singapore, WHO stated that the epidemic is showing a stable pattern, with cases confined to well-documented risk groups and few new cases are being detected.

For the countries in our region, the picture is still evolving. WHO has not reported any cases from Malaysia so far. However, Malaysian media reports have quoted the Malaysian Health Ministry as stating that as of 2 Apr, a total of 59 suspected SARS cases had been reported. There has also been a recent death that had symptoms of SARS but investigations are on going to determine the actual cause of death. As we have close relations with Malaysia and a large number of people move between our countries daily, I briefed the Malaysian Health Minister, Datuk Chua Jui Meng and his officials on 1 Apr. We agreed that we would share information and cooperate in controlling SARS for the benefit of both our countries.

The strategy to control SARS in Singapore

Next, I would like to explain our strategies for controlling SARS in Singapore and the various measures that we have taken.

To control the SARS situation in Singapore, our key strategy is to detect persons with suspected or probable SARS, as early as possible and isolate them in Tan Tock Seng Hospital (TTSH) and Communicable Disease Centre (CDC). Once isolated, we cut off further transmission of the disease. Early identification is being done through several ways.

Firstly, we have been educating the public about the symptoms of the disease and how they can be infected. We urge all those with fever and who have travelled to SARS affected countries or had contact with SARS patients within the preceding 10 days, to seek medical treatment immediately.

Secondly, our GPs, polyclinics, A&E Departments of our hospitals as well as TTSH and CDC have been organised to pick up cases quickly.

Thirdly, each time a new SARS patient is identified, MOH officers quickly carry out investigations to trace all those who have come into contact with them so that these contacts can be ring-fenced through home quarantine. Persons who are quarantined are given instructions to monitor their temperatures daily and to call MOH when they feel unwell. We also check on them daily. We thus ensure that we pick up any person who develops the disease as early as possible and isolate them in the hospital. This quarantine measure also prevents any potential spread to others in the community from delays in getting to hospital.

However, contact tracing is not 100% foolproof. We may not be able to trace everyone who is a contact. So we have to appeal to all Singaporeans that if you or your children are sick with fever, you should not go to work, your children should not go to school but you should see a doctor immediately.

An important characteristic of SARS is that it is more infectious when the patient is sicker. Hence, it tends to be transmitted quickly among healthcare workers who are not appropriately protected when they take care of SARS patients. As such, another key strategy is the implementation of enhanced infection control measures in all hospitals. In addition, my Ministry decided early on to concentrate all SARS cases in TTSH and CDC. All staff in TTSH and CDC practise enhanced precautionary measures to prevent getting infected by patients. These include wearing of tight fitting masks, gloves, gowns and special hoods (PAPR - Positive Airway Pressure Respirators) when they perform higher risk procedures on patients. Staff there also monitor their temperatures three times a day so that any healthcare worker who becomes unwell is quickly isolated. A dedicated set of staff also take care of the SARS patients and they do not see other non-SARS patients. In TTSH, no further spread among the health care staff from treating known cases have occurred after the measures have been fully implemented.

Besides TTSH and CDC, staff members in all hospitals also exercise the necessary precautions when handling patients with fever and pneumonia. Patients who come to the Emergency Departments with a fever and who could be a suspect SARS case are identified quickly and managed separately from the other patients.

With these measures, WHO has assessed that the outbreak here due to the first 3 index cases is coming under control. We are currently working hard to ensure that clusters of infection do not develop from the new imported cases of SARS.

To reduce the number of imported cases, we are carrying out health screening on incoming air and sea passengers from affected areas. This complements the checks that airlines have put in place at check-in counters. Flight crews are also on the lookout for ill passengers on board aircraft. All travellers who enter Singapore are given a Health Alert Notice to explain the symptoms of SARS and how they can get help if they fall ill with suspected SARS. We will also be requiring all visitors to Singapore to complete a Health Declaration Card soon.

The next stage

The indications are that we should be able to control the present outbreak as new infections are tailing off. However, there continues to be a risk that new clusters of infection may develop from unrecognised cases of SARS, particularly in patients with multiple medical problems where the presentation is not typical. In the absence of a definitive diagnostic test, it is very difficult to identify and isolate such cases early. At the same time, global travel means that new imported cases will occur in the future. Screening of travellers at airports and seaports are limited in their effectiveness as it will not pick up persons during the incubation period. Persons can therefore be well as they pass through the screening procedures and develop SARS later. A single imported case can trigger off an outbreak involving many cases, especially if he or she is a super-spreader even though we quickly institute the control measures to isolate and ring-fence ill persons and their contacts so as to limit disease transmission. Hence we must all be prepared to accept that SARS will not just disappear after some time. We are in this for the long haul.

It is important that Singaporeans realise that controlling SARS is not just the job of the MOH or the government. Everyone must play their part to control SARS. There must be a change in mindset, in social behaviours. Heed our travel advisories and do not travel to SARS-affected countries. If you have fever or are unwell, do not go to work. If your child has a fever, do not send your child to school. See a doctor and stay at home until you are well. When you go to the doctor's clinic, wear a face mask so as to reduce the risk of spreading infection to others. If you cough, cover your mouth and nose with tissue paper or a handkerchief. Do not spit on the floor or in the open. Practise good personal hygiene and wash your hands frequently. It is in your own interest and family's interest to work together with the Government to prevent and control SARS in our community. If your are sick and you seek medical treatment immediately, your chances of recovery are better. You are less likely to infect your family. If everyone who has fever and is unwell stays at home and away from crowds, then Singaporeans will have greater confidence that the likelihood of their meeting a very infectious person in a crowd will be much reduced.

SARS is a new threat to our health. As more information on the disease becomes available, we should be able to tackle it more effectively. For example, once we have a diagnostic kit, we can operate with greater certainty. But a vaccine or a cure would take a long time. In the meantime, SARS is likely to be an on-going health threat worldwide. The disease may well flare up around us again in the future. We must be resilient, adopt the necessary precautions and soldier on. If all Singaporeans work together, I am confident we can cope with this disease without unduly disrupting our normal lives.