Severe Acute Respiratory Syndrome - Press briefing
Friday, 21 March 2003, 11:30
Palais des Nations
World Health Organization
Dr David Heymann, Executive Director, Communicable Diseases
Dr Guenael Rodier, Director, Communicable Disease Surveillance & Response (CSR)
Dr Max Hardiman, Medical Officer, CSR
Dr Klaus Stohr, Scientist, CSR
Dr Julie Hall, Medical Officer, CSR
Mr Dick Thompson, Communications Officer
Q. We understand that you are closer to identifying the cause of this disease. Is that true? Could we have more information?
A. Dr Klaus Stohr: Since yesterday [Thursday 20 March], two more laboratories have identified the Paramyxoviridae virus in specimens from patients with SARS. One of the laboratories could identify one of these viruses as a virus that could be isolated with culture outside the patient. The tests are currently ongoing. We are having another telephone conference today at 13h30. We really have to look at the data. We are cautiously optimistic. But we also want to come out with the facts. We have to wait until we have the data.
Q. Have you pursued this line of investigation in China as well? Has the team arrived there?
A. Dr David Heymann: As you know, we have had reports from the Chinese government on tests that they’ve done and also on some organism that they have identified. They have identified Chlamydia but incidentally. But they don’t think this is the cause of the outbreak. A WHO team will arrive this weekend to review the records supplied by the Chinese authorities. We expect to have more information available early next week. We are now closer to reality that this Paramyxoviridae virus has caused this, you have to realize this is a whole range of different viruses, from some that cause measles and mumps and from some that cause common respiratory infections in many people and which are sometimes even asymptomatic. Just because we found it circulating in some people does not mean that it is not circulating in others. A whole series of studies have to be done to find out if this is the cause. And if this is the cause, what this extended spread would be.
Q. Could you please expand on your statement that you are “cautiously optimistic” that you have found the causative agent?
A. Dr Klaus Stohr: The WHO collaborating multi-centre project is turning around data within one week which are normally distributed and digested and look at in months or years. More and more laboratories are finding Paramyxoviridae virus. What is promising is that many other Paramyxoviridae viruses can be excluded. Hendra and Nipah virus have not been found, nor have mumps and measles. Respiratory syncytial virus was found in few samples. What is promising is that in one sample the virus was found by electron microscope and no other Paramyxoviridae virus could be detected. So we have a Paramyxoviridae virus-like particle which is not any of the known Paramyxoviridae viruses. That is what we are looking at. Next steps are more cell culture, and more particle trials perhaps in animals. In essence, we are turning around information usually generated in months or years within hours and days.
Q. I am not a medical expert, but once you have virus detected and identified and determined, what do we do next? Where do we go from here?
A. Dr David Heymann: Let me try and explain. Once the cause is identified, then a diagnostic test can be made. A test which may detect infection in blood or other body secretions. Once this had been done we must use what we call “Koch's postulate” to tell us if we have an organism, and we must be clear that this organism is causing the disease. Then epidemiological studies are needed to determine whether the disease is asymptomatic in some people who have become sick or whether they are healthy and can be removed from the list. There is a whole process of epidemiological investigations after the virus is identified.
Q. Last time, WHO's overall assessment was that the outbreak was being contained outside China, Hong Kong and Viet Nam. What is your assessment based on information now?
A. Dr Julie Hall: Figures of verified and confirmed cases are published on the web every afternoon. There will be more figures this afternoon. I think that what is clear is that the major areas of transmission of this disease are in Hong Kong, Viet Nam and, obviously we have yet to see, China. Hopefully we will have much more information next week. What we do know is that cases that have occurred outside these countries have occurred in hospital with no further spread of infection. What is very promising is that heightened surveillance, early signs and symptoms, people can be taken into protective hospital environment to prevent further transmission of this disease.
The WHO Global Outbreak Alert and Response Network has three field teams currently undertaking advanced epidemiological investigations. In Viet Nam, WHO has a 9-person team, in Hong Kong 6 persons, and by the end of the weekend we hope to have 5 people in Beijing. Institutions from the following countries and people drawn from WHO and GOARN are represented in these teams – New Zealand, USA, Japan, Australia, Sweden, Germany, France and the UK. These three field teams are working extremely hard to get as much information as possible on what is happening in hospitals and in communities. Where we have effective hospital infection control transmission is dramatically reduced. And where patients are given good supportive care, especially in intensive care units, a small number of patients are stabilizing and may be discharged from hospital.
Q. You mentioned earlier that for the core cases of Chlamydia identified by the Chinese authorities, they did not believe that this was cause of outbreak. Once the team is in China, do you expect that we will have a clearer picture?
A. Dr David Heymann: What the Chinese have told us is that they identified Chlamydia in core specimens and that these were preliminary results. They have not yet determined what is causing the outbreak in China.
Q. We ask whether we have a community outbreak in Hong Kong, but the Hong Kong authorities maintain that this is not the case.
A. Dr David Heymann: What we see is that initial cases are admitted to a hospital. Those cases are then in close contact with health workers and it is health workers who became infected first. So last Saturday, based on the information from we had from Hong Kong and Viet Nam, more than 90% of all the cases were health workers, the other 10% were index cases, that is cases who were admitted to hospital with the disease before health workers were infected or their family members had got infection. What we are trying to prevent is the cases going from family members and health workers to others who are not in the family. If that would occur, it would be a community outbreak, i.e., within the larger community than health workers and their families.
Dr Guenael Rodier: When dealing with a community outbreak, it means that the chain of transmission spreads rapidly and it is difficult to trace it retrospectively. The question is who infected whom. In these cases, it was easier because it always starts with a health care worker and the disease is transmitted by close contact with the patient. We have a major pattern of nosocomial or hospital-acquired infection.
Dr Max Hardiman: The WHO travel advisory issued last Saturday was based on a risk assessment and the quality of the cases being described and located within hospitals. Other than health care workers and their families, there is no transmission going on in communities to which travellers may become exposed. That is why we have reviewed the new information and the WHO advice stills stands: no restriction on travel is recommended.
Q. Given what has happened over the past 10 days, how would you rate the international health community’s performance in coping this new and mysterious disease?
A. Dr David Heymann: For the past seven years we have been strengthening WHO’s ability to deal with infections that are of global and international importance. We have done this through various measures that permit us now to alert health facilities very rapidly. This is particularly important now that diseases have potential to travel around the world, or where a disease is naturally occurring without known cause or suspected of being deliberately caused. We have learned many lessons in the past week and see places where the links can be strengthened through our ministries of health, between countries and within WHO to make the next event more easy to manage. This is being undertaken within the context of the revision of the International Health Regulations. We have seen that WHO can be operational in this area. Through the global surveillance network, WHO has prevented many additional cases of transmission.
Dr Guenael Rodier: This has been a good exercise in preparation. The global community is responding very positively and seriously to this alert. This real exercise shows that the system can work and that there is justification for such a global alert, which will be a mechanism that functions as the operational arm of the International Heath Regulations.
Q. You said there was room for improvement. Could you elaborate?
A. Dr David Heymann: We live in a world that is not only globalized but inter-connected. We need to make that interconnection even stronger. This will be part of the strengthening of the International Health Regulations so that better channels of communication exist to communicate directly with governments. We had several ways of communicating the global alert and we chose the press to disseminate this information directly to governments. In the future we can choose the press and electronic networks.
Dr Julie Hall: Through the Global Outbreak Alert and Response Network WHO is able to mount a response within 24 hours. The network consists of over 150 institutions around the world. Through the network, we have been able to get personnel to go to the field, to get guidance and advice and to gather protective equipment and other supplies within 24 hours. WHO was able to mount an unprecedented response to this infection through the global alert.
Q. What is the WHO global updated figure, including China, of suspected cases and deaths? Last time I asked you whether you had given up on influenza.
A. Dr David Heymann: Influenza has not been isolated from any of the patients in this outbreak. Therefore influenza as a working hypothesis has been replaced by that of Paramyxoviridae virus. Influenza is very low on our list of suspicion. Global figures as of today will be released at 16h00.
Q. Do I understand from what you have said that Paramyxoviridae virus may be present in healthy people?
A. Dr David Heymann: The reason that we need to have a diagnostic test is to be sure that Paramyxoviridae virus is not floating around in asymptomatic people. We need to see if these people were exposed less intensively than others who got a mild infection or did not show any symptoms at all. Regarding China, there may have been a related outbreak in the same geographical area and in same time period in Guangdong where 305 cases were found. Those cases were given to us by the Chinese government in February. This will be verified as teams begin to work in China and will be fully reported.