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K E Y P O I N T S

As previously reported, the World Health Organisation (WHO) issued a global outbreak alert about Severe Acute Respiratory Syndrome (SARS) on 15/16 March.

Since then, overseas cases have increased, particularly in China and Singapore. As of 26 March, the WHO reported a total of 1323 cases have been reported from 13 countries.

According the WHO, on 26 March, the following areas of the world have been affected by the disease: Toronto in Canada; Singapore; the Quangdong province, Hong Kong special administrative region of China and the Taiwan province in China; and Hanoi in Vietnam.

Eleven laboratories in nine countries have joined together to research the cause of the disease. Progress has been fast, and viruses from two different families - Paramyxoviridae and Coronavirus - identified as possible causes. At the moment diagnostic tests are being created for these viruses.

Updated travel advice - 4 AprilThe WHO has now advised against non-essential travel to Hong Kong and the Guangdong Province of China. This is a temporary recommendation and will be reviewed daily by the WHO. This advice has been echoed by the UK's Department of Health.

People travelling to other affected countries are advised to be aware of the illness and its symptoms - a high fever (38°C) and one or more respiratory symptoms, such as a cough, shortness of breath and difficulty breathing.

According to the WHO: "Based on currently available evidence, close contact with an infected person is needed for the infective agent to spread from one person to another. Contact with aerosolized (exhaled) droplets and bodily secretions from an infected person appears to be important. To date, the majority of cases have occurred in hospital workers who have cared for SARS patients and the close family members of these patients."

The time between becoming infected with the disease and symptoms appearing (the incubation period) appears to be between 2-7 days.

In Singapore, people who may have come into contact with the disease are being quarantined to try to contain the virus.

The WHO is constantly monitoring the situation, updating advice on a daily basis and keeping the public fully informed.

Severe Acute Respiratory Syndrome (SARS) - the latest progress on "mystery pneumonia bug"

Bupa investigative news - 27 March 2003 Updated
written by Rachel Newcombe, reporter for Bupa's Health Information Team

Click here for the latest SARS information

Severe Acute Respiratory Syndrome (SARS), the atypical pneumonia virus dubbed the "killer bug" or "mystery pneumonia", is continuing to be investigated by scientists worldwide and affect individuals in the Far East. Although the UK has remained relatively SARS-free, other countries haven't been so lucky. So, what's the latest situation? Is anything more known about it and has the travel advice changed?

What were the headlines?

The world media has followed this story with interest, since news of the first major outbreak came to light. Reports have continued to appear in papers and on websites throughout the globe, following the progress of the illness and watching eagerly for any signs of a breakthrough.

Recent reports had headlines such as, "Hundreds quarantined as killer virus spreads", "Cold deaths link", "Hope over deadly bug", "Drug helps mystery bug patients", "Killer bug may be new variety of common cold" and "SARS may be related to cold virus".

What is the bigger picture?

Investigations into the disease are being conducted worldwide, with collaboration from 11 laboratories in nine countries, and a host of international experts. So far a number of theories have emerged, and vital steps in the development of a diagnostic test have been made. Here's how their work has progressed.

18/19 March - doctors at the Chinese University of Hong Kong and Prince of Wales Hospital announced they thought they'd identified the virus as being from the Paramyxoviridae family (viruses that also cause mumps and measles).

21 March - Canadian researchers released findings suggesting a Metapneumovirus, which belongs to the Paramyxoviridae virus family, may be the cause.

21 March - the World Health Organisation (WHO) said a laboratory network had "succeeded in growing, in cell culture, an infectious agent that might be the cause of SARS." Meanwhile, scientists from the department of microbiology at the University of Hong Kong managed to isolate the virus and were working on a diagnostic test.

24 March - the Centers for Disease Control and Prevention (CDC) in America announced that a "previously unrecognised virus from the Coronavirus family" may be to blame. Two Coronaviruses that are known to affect humans cause one third of common colds, plus they're a common cause of upper-respiratory infection in premature babies.

Yet some of these findings seem confusing. Why have two different viruses been found in patients with the disease? Could two viruses really be the cause of the illness? These issues were addressed by WHO scientists at a press conference on 25 March:

Dr Klaus Stohr, a WHO virologist, admitted that, "Speaking as a scientist, we are looking at a very interesting and a fascinating situation. Looking from the point of infectious control, we are a bit puzzled because we are not only dealing with one pathogen [disease-causing agent], but with two."

However, he explained, "The reason why we believe that both pathogens should be given equal attention is that there is consistent finding of both pathogens in individual patients or of either of the pathogens in other patients. What we are seeing actually are three hypotheses.

The first hypothesis is that one of the viruses, for instance the Coronavirus, causes the disease, and that might be a new Coronavirus.
The second hypothesis is that the Paramyxoviridae viruses cause the disease, and that if that was the cause, it's certainly also a new Paramyxoviridae virus.
The third hypothesis is, very obvious, is that these two pathogens have to come together to cause this very severe outbreak. One of the viruses, for instance the Coronavirus, is known to live in immune cells, cells which are important for … the body's defence against infection. So what one could hypothesise is that this Coronavirus destroys, or at least diminishes, the immunity in the patient so that the second virus has practically an open door to go in and to sicken the patient beyond what this virus would be able to do normally."

Dr David Heymann, WHO executive director of communicable diseases, added that a fourth hypothesis also exists. "It is possible that both are common viruses: one found in all the patients, even though it's not causing disease ... so they could both be found but not related in any way, just there by chance," he explained. "It's a very complicated issue that's being sorted out."

Earlier Dr Julie Gerberding, director of CDC, had said of the worldwide work to identify the cause of the disease, "This collaboration among scientists led by the World Health Organisation (WHO) is unprecedented. We certainly have more work to do, but we think we are on the right track."

In addition more is now known about the course of the disease. It is believed to spread by close contact, and it's incubation period (time between becoming infected and showing symptoms) is between 2-7 days. This has led the current view that:

people on an airplane are unlikely to catch the disease - unless they had been sitting in close contact with an infected person
if a person had caught the disease while in the Far East the symptoms would be apparent within 10 days of returning to the UK.

According to the WHO: "Based on currently available evidence, close contact with an infected person is needed for the infective agent to spread from one person to another. Contact with aerosolised (exhaled) droplets and bodily secretions from an infected person appears to be important. To date, the majority of cases have occurred in hospital workers who have cared for SARS patients and the close family members of these patients."

In an attempt to contain the disease, the Singapore government has ordered more than 860 people who may have come into close contact with an infected person to stay in their houses for 10 days. The length of quarantine should ensure that any incubating illness should be revealed and treatment started before these people can pass the disease on to anyone else. Also, as a precaution to minimise the risk to children, all Singapore schools - an environment where children may come into close contact with each other - have been closed until 6 April.

“In line with World Health Organisation (WHO) and Department of Health (DoH) advice, travellers to affected areas should still be vigilant and on the lookout for symptoms which include a high fever, dry cough, shortness of breath and breathing difficulties. The research is still in its early days and more investigations are needed. But it's very positive that so many countries are collaborating to identify the cause of this illness and to develop guidelines for the care of patients with Severe Acute Respiratory Syndrome (SARS).”

Dr Rebecca Small,
assistant medical director
Bupa Group

What does this mean?

Although the mystery still hasn't been solved, it is still early days. In the short amount of time so far, the collaboration of laboratories have accomplished a large amount.

According to Dr Susan McLellan, an infectious disease specialist from the Tulane University Health Sciences Center in America, "Many people have an exaggerated view of the ease with which a pathogen can be isolated. There are millions of viruses and bacteria out there that don't even have names, some of which cause diseases that we haven't recognised. It takes a lot of good luck and as many good minds as possible working together. If CDC or Hong Kong has actually got the right virus already, they've done a hell of a job. It took much longer to find Legionnaires or Hantavirus."

"Scientists who are, by default, academic competitors are now working virtually shoulder to shoulder," added Dr Klaus Stohr. "In less than a week, they have produced results which, in other circumstances, would likely have taken months or more. This rapid advance is fuelling the hope that SARS can and will be contained."

The identification of the viruses responsible for the disease is vital to the creation of a diagnostic test for it. The idea that a diagnostic test for these viruses can now be developed is particularly encouraging. This is because the creation and use of a widely available test could allow easy screening, enabling easier tracking of the disease and faster treatment.

"A number of laboratories are very encouraged that we are getting close to having a test that could be used clinically," said Dr Gerbending. She added, however, that, "In order to translate what we're doing in the research laboratory into a clinical environment, it's going to take some time and some patience as we understand the accuracy of what we have available. I would predict that would be weeks, certainly not days. And in order to get a commercially available test, of course, that will take much longer. But we are doing it as fast as we absolutely can."

Initially there were some concerns that the disease could become a pandemic - a worldwide epidemic of an infectious disease - but it's now thought the swift actions of the WHO has significantly helped reduce the likelihood. The quarantine measures implemented in Singapore among those affected are also aimed at achieving this.

A C T I O N P O I N T S

If you've recently travelled to, or intend to travel to, the Far East be aware of the illness and its symptoms.

The main symptoms of Severe Acute Respiratory Syndrome (SARS) are: a high fever (38°C) and one or more respiratory symptoms, such as a cough, shortness of breath and difficulty breathing.

If you are travelling to the Far East in the near future, keep an eye on the World Health Organisation, Department of Health travel advice, and Foreign and Commonwealth Office websites for updated information

What does this mean to me?

Only a handful of people returning from South East Asia to the UK have experienced potential symptoms, many of which have turned out to be false alarms; this includes the previously reported Manchester businessman, who turned out to have flu. The WHO maintain that the disease is only spread through close contact, for example when living with or caring for someone with the virus. As such, it's not felt that travel restrictions are necessary at the moment.

On 25 March Dr David Heymann, WHO executive director of communicable diseases, said, "We still maintain that travel is not to be interrupted throughout the world at this point in time."

A statement from WHO on the same day added that, "Advice to travellers is being kept under constant review. SARS is an emerging disease. Knowledge about its clinical behaviour, response to treatment and mode and risks of transmission are continually evolving."

The Department of Health and Public Health Laboratory Service (PHLS) said, "In line with advice issued by the WHO, travellers from China, Hong Kong and South East Asia who develop symptoms of this kind should contact local health services. Travellers to South East Asia need to be aware of these outbreaks and take them into account in their travel plans. We are monitoring the situation closely in liaison with the WHO and other UK authorities and will issue further advice as necessary."

In the rare likelihood that you do experience any possible symptoms after travelling to one of the affected areas (see key points box above), it's important to see a doctor immediately. Despite some of the reports, Dr Gerbinding believes the outlook is good. "The fact that many of them [patients with SARS] are improving ... suggests that the majority of people will be able to survive this illness if they are in good medical care, and we're optimistic that will be the case for most people," she explained.

Summary

Fast reactions from the WHO and health organisations throughout the globe have greatly aided public awareness of SARS and have slowed its spread. Worldwide collaboration between medical laboratories is ensuring that the best knowledge and understanding is being collected and used, and developments are continuing daily.