Emergencies preparedness, response

Severe Acute Respiratory Syndrome - Press briefing

Friday, 11 April, 15:00
Palais des Nations

World Health Organization

Dr David Heymann, Executive Director, Communicable Diseases
Dr Guenael Rodier, Director, Communicable disease surveillance and response (CSR)
Dr Mike Ryan, Medical Officer, CSR
Dr Mark Salter, Medical Officer, CSR
Mr Dick Thompson, Communications Officer

Mr Dick Thompson.
This is a status report on SARS. On 12 March, WHO issued the first SARS bulletin. It was four weeks ago that we issued the second. I will now turn this over to Dr David Heymann, the Executive Director of the Communicable Diseases section.

Dr David Heymann:
Thank you Dick. Thank you all for coming this afternoon. It was just four weeks ago tomorrow that we went out with our second alert about SARS. The first alert actually went out on 12 March, when we had become aware that there was a new infectious disease of unknown origin in both Viet Nam and Hong Kong. At that time, WHO went out with a press release – it was a Wednesday– telling the world about a newly identified disease in Asia. During the period between the 12th, which was a Wednesday, and Saturday, which was the 15th, the Canadians identified this same disease in Canada and also identified that it had not only occurred in one person but in two family members. At the same time, there was a patient – a doctor – who had gone from Singapore to New York for a medical congress. This doctor, before he left Singapore, had treated a patient for a disease that he did not recognize, but which had come from Hong Kong. He arrived in New York, was there for a short period of time, fell sick, and went back to Singapore. While he was on the aeroplane, the Singapore health authorities called WHO at 02:00 a.m. and told us that he was on the aeroplane. When the aeroplane stopped in Frankfurt, he was taken off it and put into isolation. Having noticed that the disease had begun to spread, we decided to make the global alert on 15 March, which gave a case definition so that everyone could see what the disease looked like and also identified this as a disease that could travel on aeroplanes and that passengers should be aware of this. That alert went on, in effect, and after that, as you know, we have been following the countries and cases of SARS. What is important to note is that after that alert on 15 March, there have been no countries that have had the disease that have had the same extent of outbreak as had occurred before the alert in Viet Nam, in Singapore, in Hong Kong and in Canada.

The global alert, it appears, was effective in stopping localized outbreaks. You will remember the reasons why we went out with that global alert. The disease was unknown, it was spreading around the world, and it was affecting mainly at that time health workers. It was a disease to which health workers were at risk and there were many people who were severely ill on respirators. So for all those reasons, we went with the alert.

On 2 April, we went out with another alert. This was to passengers who would be going either to Guangdong or Hong Kong, recommending that they postpone any unnecessary travel to these areas. The reasons that we recommended this were twofold. In Hong Kong, we noted that after 15 March there were still people travelling on aeroplanes out of Hong Kong with the disease. In fact, nine persons had travelled to various countries, mainly businessmen or tourists. At the same time, there was a new element in transmission in Hong Kong, and that something in the environment appeared to be taking the disease from an infected person to others. We put the same restriction on Guangdong Province, not because we understood the epidemiology but because we did not understand what was going on in Guangdong. But we knew that there was an epidemic that we thought was still going on. That recommendation remains in effect today and all countries are now working to contain the outbreaks. What we have seen is that a developing country such as Viet Nam has been able to contain the outbreak, and we believe that outbreak will remain contained now, there are a few cases. Singapore, Canada and Hong Kong are working very hard to do the same, and we believe that all three will have success. Hong Kong has issued some new measures today that will make sure that contacts remain in quarantine and do not travel outside Hong Kong during the period when they are under quarantine. This is how things evolved in the first few weeks.

What I would like to do now is ask Mike Ryan if he would talk a little bit about what we know about the epidemiology of this disease from the epidemiology collaborating group.

Dr Mike Ryan:
Thank you David. The global SARS alert issued on 12 March was a direct response to a specific threat identified by the global alert and response system. This system continually tracks the development and spread of epidemics around the world. In response to that, case definitions were rapidly developed with the early information on this new disease and provided to national and international teams on the ground. This allowed the early identification of cases in other countries and has, to a great extent, allowed those countries who have imported cases to immediately contain the threat of local transmission in their own populations. Specific and detailed measures for the surveillance of cases and contacts of SARS have been developed and disseminated. WHO now receives daily reports on the disease situation from those countries that have had cases and has requested immediate reporting of cases detected in other countries. WHO is also using other information sources, such as the media, UN organizations and partners in the Global Outbreak Alert and Response Network (GOARN) to identify areas in which new cases may occur, and immediately and actively follows up with those countries to establish whether cases are occurring and what measures countries are implementing to ensure containment.

An epidemiological team at WHO systematically analyses data and conducts risk assessment on a daily basis. All verified information is posted to the WHO web site, as you well know, with updated figures, graphs and maps detailing the impact and spread of the epidemic. The SARS operational team in Geneva and in our regional office in Manila is providing real-time 24-hour advice to countries on SARS surveillance, preparedness and response measures. In addition, targeted travel advisories have been released in order to protect the health of travellers and decrease the risk of further international spread.

GOARN was rapidly mobilized in response to this SARS epidemic. We have worked with partners in the network to support international teams in China, Viet Nam, Singapore and Hong Kong Special Administrative Region of China. These teams involve 60 experts representing 20 international organizations and 15 nationalities, working with national authorities on case management, infection control, surveillance and laboratory and epidemiological investigations. Operational teams in the field are brought together by telephone and video conference on a daily basis to review progress and plan further actions. In this sense GOARN is providing an operational platform, mobilizing clinicians, data managers, infectious disease experts, epidemiologists, laboratory experts and logistics people as part of the international mobilization of resources to address this global public health problem.

WHO logistics bases in Manila, Bangkok and Geneva have been working together with external agencies and donors, such as MSF [Médecins Sans Frontières], USA, Australia, Japan and France, to ensure the coordinated supply of approved protective and clinical management equipment. This is to ensure that appropriate supplies are reaching countries in a rapid and coordinated fashion.

Epidemiologists around the world have come together to look for answers to the spread of this epidemic and to work together to constantly review the control measures that will end this epidemic. The group works using global connectivity, allowing each site to work in real-time collaboration with others, agreeing on priorities, methods and implementation of specialized investigations. The outbreak has been described in great detail, and the major route of transmission has been identified. However, there remain unanswered questions regarding disease transmission. The group has designed and is now implementing a number of targeted scientific investigations looking at disease transmission.

I would like to refer now to some of the specific updated information as of 10 April, yesterday evening. We now have 2781 cases, including 111 deaths, 1337 people have been discharged from hospital or recovered. That would indicate 59 new cases in that 24-hour period, 9–10 April. Seventeen countries are now affected by the outbreak, but it is important to note that only in four of these is there local transmission documented. No new foci of transmission have been identified in the past three weeks. That is, all cases in the past three weeks that have been imported to other countries have been adequately isolated and contained, and no further local transmission has occurred.

I think that is it on the epidemiology side.

Dr Heymann:
Thank you Mike. Then Mark Salter, I wonder if you would talk a little bit about the scientific collaboration among the laboratories.

Dr Mark Salter:
Certainly. There are two areas that I would like to talk about. One is about the WHO collaborating network of laboratories, as well as the WHO collaborating network of clinicians. I will start off by talking a little about the work of the laboratory network, which was established under WHO auspices.

At the present moment in time, 17 laboratories around the world from 9 countries are involved in dealing with, identifying and developing tests for the diagnosis of the causative agent of SARS. Over the past five weeks, many of you will have been aware of the breakthroughs in working collaboratively that have occurred, such that a number of viruses have come into the frame. Three weeks ago, we were talking about candidate viruses from the paramyxovirus group, the coronavirus group, and various other groups. We now have whittled that down to one most probable candidate, that of a new, previously unrecognized coronavirus. The laboratories have been working together to establish effective tests to identify this agent from various samples taken from patients who have SARS and from individuals who have had contact with those who have SARS. These are currently being analysed in various laboratories around the world to try and standardize these, so that in the coming weeks and months we will make available, and have made available, definitive diagnostic tests that which help us rapidly to assess individuals who are presenting with symptoms of SARS and place them into appropriate categories so that they can receive the appropriate treatment, as and when that is developed. We have had the opportunity to use this agent that has recently been isolated and placed into animal models, and these are proving useful experiments. We are now learning a lot more about the virus. We hope that in the coming days and weeks we will have more information to confirm that the coronavirus in indeed the causative agent.

The laboratory network has operated via a secure web site, where the details of its analysis and testing of samples has been placed confidentially so that various members of these networks can see it, act upon it and share relevant information. As recently as today, we have information that is of great interest and concern, particularly to the clinical component of WHO's efforts to try and control SARS, and that is the use of ribavirin, an agent which you are probably all aware of now. It is an antiviral agent that is used in the treatment routinely of Respiratory Syncytial Virus in children and a number of viral haemorrhagic fevers, with varying degrees of efficacy. The US has tried using ribavirin in tissue culture to inhibit the coronavirus activity without any success. This would suggest that in the in vitro model of tissue culture, ribavirin is ineffective. However, this does not exclude its usefulness in the treatment of patients with SARS at this stage. These are only preliminary findings.

As and when we have definitive evidence to suggest that the coronavirus is the primary causative agent, the next step that everyone will be anticipating is the development of a vaccine. Discussions are currently ongoing within the laboratories as to how this can be taken forward. As and when information becomes available, the world will be availed of that.

The other network that has been established is the clinical network. This currently has clinicians from 11 countries. The clinicians now involved are too numerous to mention. Many of them are working under extreme circumstances, in that, as we are all aware, the large numbers of individuals who are primarily affected by cases before they have been recognized as SARS are health care workers themselves. So these doctors are not only caring for patients, they are caring for colleagues, which has obviously put a great deal of strain upon them. We now know from their work and bringing it together, again on a secure web site, that of those who contract SARS, 96% are getting better; 4% are dying; 10% of all the numbers are requiring admission to intensive care units, of whom approximately 50% are requiring mechanical ventilation.

So what has the clinical network allowed us to achieve? It has allowed us to have a clear consensus as to what the clinical presenting signs are with SARS. It has allowed us to determine exactly what we would expect to see in the progression of SARS. What it has not allowed us to do is to develop clinical indicators that clearly discriminate between the two groups of SARS that we now recognized. That is, the 90% that have an uneventful course and spontaneously resolve, get better, and the 10% who move on to require intensive care therapy. What we can say about that group and about the group that die is that they are usually slightly older, over 40 years old, and that at the time of presentation with the symptoms of SARS, they have other underlying medical conditions, such as coronary heart disease, diabetes, asthma, and other chronic lung problems.

Working together, we have been able to establish guidelines for the management of SARS patients. These guidelines are constantly updated as new information becomes available and form the basis for many nations to develop their own, more appropriate guidelines which they can implement, depending on the circumstances those countries are under. It has also allowed us to more adequately develop effective infection control measures, which have been fundamental in bringing to a halt in many countries the transmission of SARS.

The future. Therapeutic treatment of those 4% who are dying now becomes probably the most fundamental thing the clinical network can achieve. We are working together with our clinical colleagues around the globe to try and establish effective protocols for systematically evaluating the effectiveness of treatment. Ribavirin is one that, as I have mentioned earlier, has been used widespreadly, as have intravenous corticosteroids. We are aware of a number of colleagues in China and Hong Kong [garbled] using immunoglobulin and convalescent sera. The aim of the collaborating group over the coming weeks will be to bring this information together in a systematic form so that we can actually rule out those therapies that are ineffective and push forward with those therapies that are proving to be effective. Thank you.

Dr Heymann:
Thank you. And now Guenael Rodier, would you like to say ....

Dr Rodier:
Very little to say, everything has more or less been said. But as I’m overall coordinating the different groups it’s very clear that the international collaboration has worked very well for all the different groups, the epidemiological groups, the clinical groups, the laboratory group, which allowed us to provide, I think, sensible travel advice. And overall today we simply have two major foci of transmission and a number of cases where exportation has occurred. Again the containment of these exported cases is properly done and now the focus is certainly on more case finding and contact tracing in these two large foci, mainly Hong Kong and Guangdong province. And that requires a lot of ground troops, epidemiologists in the field. Interviewing patients and possible contacts and following these contacts is a large task requiring discipline but that I think is going well and at the moment the key point is to keep surveillance going globally. And certainly not to say: because this is more or less contained in a number of places there is no longer a need for strong surveillance. I think it is important that cases continue to be detected on time and isolated on time. Certainly we can still have exportation of cases. It could happen also that some chain of transmissions remain undetected and it takes time to bring together all the pieces of what is today, or has been a complicated puzzle. That’s all I would say.

Dr Heymann:
Thanks, Guénaël. So you’ve heard a little bit of overview from all the different people and now we’ll open it up to some questions. Just to tell you that in June in Geneva there will be a meeting, a Global Scientific Meeting, on SARS where all the different collaborators will be invited to attend and that’s under preparation now. So back to you Dick.

Questions and answers

Q. I have three questions. The first one is: on 9 April in your press release you mentioned there might be stringent measures of control in Hong Kong so Hong Kong government started putting quarantine on family members of patients. Is that what the stringent measures the WHO recommend or you actually anticipate something even stronger? Second question is: as you said the Hong Kong health care system is overwhelmed and there is a great concern how long they actually can sustain so I wonder if the WHO has any advice for them or under this global network would it be possible for outside help in terms of helping the health care system? Maybe I wait for your answers before I ask my third question.

A. Dr Heymann:
Well let me answer those two because just before we came here we spoke with Dr Margaret Chan, the Department of Health in Hong Kong. Hong Kong has instituted now a system where all contacts of patients of known cases have been asked to remain in quarantine for a period of 10 days and during that period of time they will not be permitted to travel outside of Hong Kong. This is an effort of Hong Kong to stop the spread of the disease internationally and we believe it will be effective. The second, we have also talked with Dr Chan about the need for additional people. WHO does have a team working there and we will reinforce our team with some additional people because there are some cases which require more tracing or contact tracing, trying to figure out where they came from. And there is a need for manpower in Hong Kong and we will be supplying additional manpower for that.

Q. OK. My third question concerns the figures of China and Hong Kong. The outbreak started in Hong Kong in March and now we have almost a 1,000 cases and in China the outbreak started in November last year and they have 1,090 cases according to the WHO figures, and in Hong Kong we have 6.8 million people while in China we have 1.3 billion. So my question is: assuming these two sets of figures actually reflect realities, can you explain to me what we can learn from China or what China has been doing that China eh, Hong Kong didn’t do, that we have so, you know, so many cases. Thank you.

A. Dr Ryan:
You’re right the figures for Hong Kong are what you say and for China. We’ve just come out of a very detailed debriefing with our team that has been in Beijing and Guangdong and the data is currently being reviewed. However it is quite clear that the authorities in Guangdong have carried out very detailed surveillance of the cases and the numbers reported from Guangdong do in fact represent reality. The conditions in Hong Kong may have been very different than in Guangdong. We saw great amplifications in the hospital environment in Hong Kong initially and we also saw some amplifications of the disease associated with hotels and particularly apartment buildings. So clearly we’ve seen unusual patterns of transmission in Hong Kong. We’ve a very densely populated city and clearly there are potential environmental routes of transmission that need to be established. In Guangdong the outbreak has not been as intense but we also have to look at all the other provinces in China to see what is going on there as well.

Dr Heymann:
I might just add that in Guangdong the team has found someone who the Chinese believe might have been the first case. The question remains is: are all these cases from that case who got infected from some source in nature, or have there been repeated infections from nature into other people in Guangdong. And they are trying now, the team, to trace back and see if all cases can be traced back in a chain from the present back to one person or whether there might have been other times when the virus or the cause of this disease came from nature into populations during this four-month period. And those are some of the questions that need to be answered.

Dr Ryan:
Just maybe to add on that – further WHO Outbreak Network staff will be going to China to work with the Chinese authorities on exactly these investigations and that team will be greatly strengthened over the coming weekend and early next week.

Q. David, there was a press report citing a CDC official saying basically that people would be increasing the risk if they were in airport terminals like in Hong Kong etc. What’s your response to this statement?

A. Dr Heymann:
Our statements, WHO, are based on the evidence and we have no evidence that there’s any more transmission in an airport than there is anywhere else in Hong Kong, except in areas where we know there’s transmission; so we have not said that there would be an increase in transmission in airports. We do know that nine passengers left Hong Kong with the disease and in some instances people who sat next to them or in the seat before or behind them, did become, we believe, infected and developed SARS, but the virus has not circulated within airplanes to a wide number of people within airplanes and we have no reason to believe that it’s circulating in airports.

Q. Sir, two questions. First one, if you can actually tell a little bit more of this first case that is being investigated, who is the person, where does he work etc. And second is a technical question on the press release. The French version says that the consequences of the, the economic consequences of the SARS is 30 billion; in English it says 6 billion. So, we would like to know if there is any difference, depending on the language that we read.

A. Dr Heymann:
I’ll try to correct first. The French got the most updated figure. 30 billion is what a fellow named Roach has recently said. The 6 billion was last week in the newspapers, and for some reason the English version didn’t get updated, so there’s not a difference between what the French should read and what the English speakers should read.

Q. 30 billion is what the latest estimate of someone named Roach, is that right?

A. Yes, yes, an economist, yes.

The first case in Guangdong – Mike, do you want to say anything about it or….?

Dr Ryan:
There are a number of reputed first cases. I think it’s very important that we can’t pin this down to an exactly one first case and that’s… I would not like to start speculating about who that person is or what that person does because it’s very important now that we work with the Chinese authorities to go back and fully investigate what that person does for a living, or what those people were doing for a living, who their contacts were, what context they were living in. And that needs to be done and is being done right now – so I wouldn’t like to speculate on…. and we have to really be precise and I hope you understand that we have to be absolutely precise when we start going back to that level of detail. There’s a tremendous chain of connections between people that has to be established. So, WHO will put out information on that investigation but I think it would be premature at this stage to start speculating.

Dr Heymann:
And it may be that the first case is never identified.

Q. Dr Heymann. We are reading reports that in places like Beijing there may be more positive cases than has been reported by Chinese authorities and I believe in your interim report it suggests that although Guangdong is doing quite a good job in trying to identify the positive chases, other parts of China would need to do more. How concerned are you that we may yet see another big cluster of positive cases in big cities around China?

A. Dr Heymann:
Our team has told us that they are very confident that the epidemic in Guangdong has peaked, has reached a height, is now decreasing but that there are still cases in Guangdong. The team is also very concerned that there are cases throughout China, they believe that there are cases throughout China and they will be working now with two different teams in China – one in Guangdong and one working in Beijing and Shanghai at the start. We told the government that we have heard conflicting reports from health workers, that what’s occurring in Beijing is more serious than what the government has told us and they have invited our team to work next week with them and clarify the situation. So we will be able to give you more information next week.

Q. I too have three questions but they are very short. Dr Salter, you mentioned that once you find out, have positively identified the coronavirus as THE virus, that you would then be working on vaccine. Now, how long would it take to take to develop a vaccine and would it be prudent perhaps to jump the gun and start working on one now, and not wait a few weeks? Second question is, you mention that there were certain treatments that are being implemented, ribavirin, some steroids and so forth. Is there any indication that any of these treatments are working or is it being done because, well, there’s nothing else to be done? And the third question, and maybe you can answer this one David is, do you think that the World Health Organization is perhaps partly responsible for the hysteria that seems to be travelling around the world over this epidemic?

A. Dr Heymann:
Let me answer the first one and I’ll give a little bit on vaccine and then, Mark, I’ll turn it over to you – the third one.

Lisa, there would have been hysteria about this disease no matter what happened. This disease occurred in Hong Kong, the press had already become fully aware of it – just ask Esther – and the press had already caused great concern in Hong Kong. What we did was, we went out to take a situation which was rather chaotic in Hong Kong and make sure that the rest of the world understood what was going on in Hong Kong, and also in Viet Nam and other parts, and knew that this disease was a very serious disease to health workers. We at no time said that this disease was airborne, some of our partners in other countries did say that, which raised the level of concern even greater. We have been very careful to put out only the evidence that we have, and that is, close contact and some factor in the environment in Hong Kong.

So, the answer to your question is, I don’t think WHO is partly responsible for this. I think this is an event which occurred which would have caused great concern throughout the world and, if WHO has done anything, it’s brought the collaborators together so that at least all health workers throughout… and ministers of health understand the disease and, when they have questions, can go to the Web site to find out the information.

Regarding vaccines and drugs, I’m going to turn it over to Mark but I just want to say one thing – we still don’t know yet whether this disease will become an endemic disease, like TB, like malaria, or whether by the intensive containment activities that are going on throughout the world, this disease will be driven back into nature. We don’t know that and we can’t make projections because we don’t know some simple facts. Are there people who are infected who don’t have symptoms and who are carrying it around the world? Are there people who have a less severe form of disease than what our case definition sets out? We need to understand all of this before we can even make a forecast but at present we don’t know – our hope on 15 March was that we could get the alert out and if the disease would be stopped and not spread and be contained and disappear and not become a regular part of human disease. So, therefore, if this succeeds there would be no need for a vaccine or drug. If it doesn’t succeed there would be a need, and Mark I’ll turn it over to you now.

Dr Salter:
Nothing happens in isolation, whilst we say that vaccine development is something that we would be pursuing more actively once we’ve established whether the coronavirus is actually the primary agent. But it wouldn’t be to the exclusion of doing anything now and indeed the efforts that are being made in the laboratories to isolate, culture the virus, study the virus, understand its nucleic acid and its genome sequence, are all steps that would be taken in normal measures to develop an effective vaccine. So, although the vaccine is not at the front of our thoughts at the moment, it is certainly on the back burner where it is being worked on.

And how long was another question you asked, how long would it be? This is a very difficult thing to know. There are effective coronaviral vaccines for animals at present on the market. Coronaviral vaccines have not actually been developed primarily in the past for human infections. And so we need to turn to our expert veterinary colleagues who’ve developed the coronavirus vaccines, perhaps to give us some technical insight into what they’ve learned in the development of their veterinary vaccines. So, how long? There is no immediate answer. We may be looking at six months, we may be looking at a year. Not only do we have to actually establish whether a virus injected into somebody could mount a response that will stop SARS developing but we also have to establish that the virus that we put in is not going to cause any detrimental effects to the individual and it may be that ultimately we will decide on using a sub-unit vaccine as the most appropriate vaccine and some of the tests that are being done now will allow us to make the decision as to which of those would be the most appropriate steps to take.

Treatments – there are no effective treatments that we are aware of to date and so we are actively looking at a whole range of known antivirals and novel antivirals. We are also looking, through our collaborators in the global clinical network, at the possibility and the effectiveness of using immunoglobulins. These are antibodies that are routinely taken from human beings and pooled in the hope that individuals who may have been exposed to other agents will have some antibodies in their sera which will reduce the effectiveness of SARS or indeed stop SARS. What we’re also looking at is the use of convalescent sera, this is sera from patients who’ve recovered from SARS and that we know contain antibodies that inhibit coronavirus infecting cell cultures. The hypothesis being that the antibodies there which inhibit the coronavirus infecting tissue culture will effectively stop the coronavirus in human beings attaching to cells in human beings and causing the disease it does.

That takes us to the next step of treatments that may be appropriate, and that’s the immunomudulators. A lot of viruses exert their pathological effects by directly destroying cells. However, there are an equal number of viruses which exert their pathological effect not directly, but indirectly by stimulating the host’s own immune responses. The pathological specimens we’ve seen would suggest that the damage caused in the lungs is not principally due to the virus but to the host’s immune response to it. If we are able to glean information from our veterinary colleagues, or from our own studies, that there are specific immunomodulatory chemicals which are causing this, then we may look into methods that will block those individual modulators and therefore reduce the severity or prevent SARS in the first place.

Q. Dr Heymann, or any of the other experts, I’m still not quite clear about the clinical picture. Did I hear you say that of those being isolated, the patients, after they have fallen sick and the symptoms are there, that only 10% need respirators and things like that? I thought that everybody needed intensive care?

A. Dr Salter:
No, the vast majority of individuals, and that’s 90% plus, have a less severe form of the disease and don’t required any major intervention. It’s only a small percentage, about 10% that require intensive therapy and, of those only 50% are requiring mechanical ventilatory support.

Q. Thank you and a follow-up. And those who get through it which, if I read you right, is 96%, are they as healthy and happy as anybody emerging from a ‘flu?

A. Dr Salter:
I’m not sure that anybody’s happy even when they emerge from the ‘flu. But most of these individuals are well by all the criteria we can actually accord to them at the present moment in time. And we are obviously actively pursuing them just to make sure that they are continuing well for the foreseeable future. Because, obviously, what we don’t know at the present moment in time is what sequelae having SARS infection may predispose you to in the future.

Q. A couple of questions. The first one really is just a clarification because two days ago, I think, the CDC came out saying that they’d actually now verified the, identified the virus. And from what you’re saying today, I think, is that we’re still in the same position as: we think it is but it’s still not a 100%. That’s just the first thing. The second thing, from some of what you’ve said, is it true to say that outside Hong Kong and China, you now think, despite the fact that there are new cases emerging in Singapore, we’ve had today I think Malaysia – do you think that really the disease is basically being contained? And the third one was, also, do you have any more on these environmental factors in Hong Kong? I mean, is it still just a hypothesis or is it more than that, have you actually really found something which did cause the disease in people?

A. Dr Salter:
Identifying a virus is only one step down the road to actually establishing whether that is the organism which is causing an infection. And yes, a number of laboratories, as well as laboratories in the United States, have identified a virus which apparently, from the tests that have been to date, is identical. It then requires a number of steps to establish whether that virus is actually causing the infection. And that is where the use of animal models is very effective, in that animals can be given this virus; if they then develop the symptoms, we can say well, it’s causing it. And if then we can take virus from those individual animals and pass it on to other animals and they too have the symptoms, we can then start saying, well this does appear to be the causative agent. And this follows what we would call Koch's postulates.

Q. I was just asking yes or no. I mean, the CDC said: we have found it. And I was saying that in fact what you’re saying is that: we think we’ve found it but we still don’t know. That’s the situation.

A. Dr Salter:
We’ve found a virus, but we don’t know whether …. We have a lot of evidence to suggest it is but we’re not in a position to say with our hand on heart that this is the only and primary causing agent. But it seems likely that it is.

Dr Heymann:
Just so you’re clear. The virus was first found in Hong Kong, first identified in Hong Kong. And then it was identified at CDC. And now it’s been identified by all the other laboratories. But, you know, the Koch’s postulates have to be fulfilled, as Klaus said the other day and as Mark has said today.

Dr Ryan:
To answer your question on containment around the world. Clearly there is always a risk in any of the countries to which a case has been imported, that there will be a further transmission. We’ve seen in Hanoi and Hong Kong that the primary route of that amplification is in hospitals and amongst health care workers. I think what we’ve seen in the countries to which it’s reached, is that we haven’t seen those secondary outbreaks recently. But there is always a risk that anyone arriving in a country can set up a chain of transmission within that country, within their family, with a hospital or within one of the special settings like we’ve seen in Hong Kong. Many cities are the same, very similar to Hong Kong. So it does require continued vigilance. The story of hope is that it is being contained, there is absolutely no question that this virus is being contained. But we have remaining threats, we have very many developing countries who are at risk from this virus. We may not have the same infrastructure. The good news is that the team in Hanoi and the authorities in Hanoi, which might be considered a developing country, have contained the outbreak extremely well. And the hope is that other countries will and we’ve been working very extensively, particularly in the Western Pacific region, with countries in Africa, countries in the Eastern Mediterranean, to increase their level of preparedness. So that, if they do receive cases, they have the same capacity as the industrialized countries to contain the virus. So I would contend that, yes, the outbreak is being contained but there are dangers and hurdles ahead. And there is always the chance, if we are complacent, that we’ll set up transmission in other countries.

Dr Heymann:
On the environmental studies in Hong Kong, we talked about this in the past, something in the environment is taking the virus from infected people to others. And this happened in an apartment complex where all the apartments were one on top of the other. There have been studies that have shown pieces of viral RNA, in other words, pieces of the genetic material of the coronavirus have been found in faeces of some persons who are infected or who have the disease. It’s not yet known whether there are just pieces or fragments of the virus or the whole virus which is infective. But we know that the faeces have some particles in it that look like parts of the virus. Now, what the theories are, are that there’s a common system or a common factor that’s taking it into various apartments in the building or there’s a common place where all people are getting together with a sick person who got infected there or some object in nature. It’s not cockroaches, that theory did not hold up. It’s not rats. Cats get a transient infection, they get infected for may be one day but the virus can’t live in them and they shed the virus off. So there are lots of studies going on but no answers yet. And that’s where they stand in Hong Kong.

Q. There are a couple of news reports indicating that, for those cured patients they still have the capability to transmit the disease in the next three to six months. Do you have any evidence to that kind of theory? And secondly, what’s your recommendation for the hospital? Should they release the cured patient right away?

A. Dr Salter:
As David just said, we have no evidence that there is viable virus being shed in an individual after they’ve been discharged from hospital having had SARS. It is something we are actively looking at because there are viral infections where we know the virus can be secreted for some months afterwards. But we have no evidence to support that in the case of SARS, yet. But we are actively looking.

Q. When you say that it is contained you mean that WHO can say, one month after, that the outbreak is under control? Because when we see the figures every day, it’s 100 more, 200 more. So, it’s really under control? And second, when we see a lot of people wearing masks, you still insist that it’s ineffective?

A. Dr Heymann:
On the first issue, it you’ve been on the web site, you’ll see graphs of each of the different places where there are major outbreaks. Each one of these graphs shows you that there has been a peak in cases and now cases are lower. So they are becoming lower. That means that the outbreak is being contained, whether it will be 100% contained and stopped, is not clear. But if you look at the graphs that are on the web site, you’ll see that there’s a decrease in new cases each day. So, that shows that the outbreak is possibly being contained and especially in places like Viet Nam where there have only been three cases identified in the past two weeks and all those cases can be linked to the original outbreak.

Dr Rodier:
If I can just say a point of clarification. When you deal with the tables we propose on the web site up to yesterday, or day before yesterday, we had only what we call cumulative figures. So this number will never decrease, it can only increase, because it just cumulates the numbers. So you will never see this number decreasing, obviously, it’s just an adding up of cases over the different days. That’s what we notice we were giving the wrong information, because necessarily that can only increase. So we proposed a new … to present the figures and we’ll show the changes between one update and the other updates. Where are the new cases? Also, how many cases are now being discharged? Which is important, because among the large number you have today, 2781, 59 are the new cases and 1337 have been discharged. So just to clarify, the cumulative numbers will always increase, can only increase, can only stop at a given point when the whole thing is over. When you come to the number of deaths, the deaths today reflect usually a course of the disease and a course of the incubation period. That means, it reflects …, people who die now have been infected three weeks, four weeks ago, ok. So, it doesn’t mean it’s out of control now because we still have people dying; again, it reflects what was the course of transmission roughly about a month ago.

Q. What about the masks? You still insist it’s ineffective?

A. Dr Heymann:
This virus, we believe, can transmit through any mucus membrane and a mucus membrane is the nose, the mouth, the eyes. And if the mouth and nose are covered and the eyes are not covered, you’re probably not protected. And if you’re not washing your hands, you’re probably not protected because coronavirus is transmitted very easily from person to person through a handshake, and then a touching of a mucus membrane.

Q. For the travel advice not to go to China and Hong Kong for the time being, when you issued it you said it’s because there are unknown environmental factors. So can we take it as if once the factors are found, I mean like sewage, then the travel advice can be stopped or amended? And also, when you said the disease is contained, does it also apply to Hong Kong and Guangdong?

A. Dr Heymann:
When we understand the environmental transmission and that it is not making a widespread risk, then we will be able to reconsider the travel recommendations. But even now, we can see that it’s only been confined to Amoy Gardens, it’s not been elsewhere which is very reassuring. And if there are no more cases being exported from Hong Kong outside to other parts of the world, and if no new environmental factors appear to develop, then, yes, we can reconsider very soon travel recommendations. And the same for Guangdong, as we get evidence from Guangdong. The figures in Hong Kong for yesterday were 28 new cases and the figures for today we understand will be more, there will be 60 today, 60-some. But that’s because they’ve now taken a backload of cases which were never reported before. They were caught in a computer system and they will come out today. So, having talked with Dr Chan just recently, we’re convinced that cases are still going down each day.

Q. David, coming back to your question about the transmission. How long, according to your estimates, can this virus live and be transmittable? And you said it can be transmitted from a mucus. So if someone might have this virus and he’s working with materials that might be exported, how long? Is it a few hours, or a few days or weeks? Because some commercial enterprises are concerned about the movement of goods from these countries and where that’s possible.

A. Dr Heymann:
Well, let me just say regarding goods – if you look on our web site there is an announcement. That we don’t consider any goods or any commercial goods a public health threat because of SARS. And it’s on our web site now.

Dr Salter:
Experiments that have been done in the past with the coronaviruses which cause respiratory illnesses in human beings have shown that the virus is not viable for more than about three or four hours if in suspension. However, there does seem to be a slight increase in it’s viability in the environment, if it’s in what we call proteinaceous materials. So for example if it was in salivary or respiratory secretions or in stool samples, it may persist for a little bit longer. Tests are being done by the laboratories that have isolated this virus to try and establish whether this virus is any more resistant. And we have no information today to suggest that it is any more resistant than any other coronavirus. So we would anticipate that if people were to wash their hands, wipe their toilet seats down with the normal disinfectants and disinfect the things that they normally disinfect at home in exactly the same way, this virus would be rendered unviable.

Q. You said that the virus is contained. Does that mean that you have no plans to widen the travel advisory? And also, when you’re looking at treatments, have you had any hints that maybe the oral form of ribavirin might prove a success, or any help at all?

A. Dr Ryan:
Can I clarify on the containment issue? We may see further countries affected by SARS. The issue of containment is not “are there no cases?”. The question is: are countries in a position to rapidly isolate imported cases and ensure that there’s no local transmission in their communities? Right now countries are being successful in doing that. We’re not seeing the amplifications that we were seeing three weeks ago in this outbreak. That does not mean that the outbreak is over. There may be further countries affected by this outbreak, there may be many, many more countries affected in the sense that they will receive or import cases. The question is …, and what we would contend is that countries are doing extremely well in the containment procedures they’re putting in place. So as of today, we believe that countries are being successful at containing the virus. That does not mean that the outbreak is over and I think it’s important to make that distinction.

Dr Heymann:
But with one caveat and that’s China. Because we don’t know what’s going on outside of Guangdong province. So that’s our concern, and that’s the concern of our team, our team said that they’re very concerned about China.

Regarding travel advisories, we’re looking on a day-to-day basis and if we should see reasons, and those would be cases being exported from a country or a new means of transmission in a country that we don’t understand, we would make the recommendation for that country as well. So, we look on a day-to-day basis. So far, the only two places are Guangdong and Hong Kong.

Dr Salter:
And on the ribavirin issue. We are looking into the efficacy of oral ribavirin but we would not anticipate any difference from the intravenous. The routes of admissions of drugs are usually for convenience and to ensure that effective therapeutic loadings are maintained and reached in an appropriate time, so intravenous ribavirin would mean that you would have an effective concentration that might inhibit the virus more quickly than if you had oral. And to date we have no evidence to suggest that either is efficacious.

Q. Are these figures, I wasn’t quite clear, these figures for new cases? Are they on the web site? And if they’re not on the web site, can you tell us when the maximum, the peak was and what are the figures?

A. Dr Heymann:
There’s a new format on the web site which gives you the cumulative number of cases, that means the cases in the country since the beginning of the epidemic. There’s then the number of new cases which have been reported since the last update of the web page. There’s another column with number of deaths, another column number of recovered, and another column tells whether or not there’s local transmission in that country. So it’s a new format.

Dr Ryan:
The curves presented are what we call an epidemic curve which is basically a day-by-day graph of the number of cases by day, by date of onset in the case, i.e., by date that the case became sick. So it’s a very real-time estimate of when the person became sick. And there’re there for the world, but there’re also broken down by country. So you can see the evolution of the epidemic by day in the countries. And it’s very helpful for you to be able to see that because you can see the trend in each country over time.

Q. I just want to ask a question about, when a person becomes infectious, do you have a clearer picture of exactly at what point somebody becomes infectious? Because there was some suggestion there could be kind of carriers of this disease and that this was one of the big dangers? In other words, they didn’t develop the symptoms of it but they could be carriers.

A. Dr Salter:
We have some information now that individuals will start …, we can see the virus in individuals who have SARS at just a few days. However, we’ve also found that in stool samples of patients who, after they’ve been discharged, …. but we have no evidence, as I was saying earlier on, to say that this is viable virus. And secondly, we still don’t have information to know what the infectious dose is, this is how many virus particles you need to take on board to actually develop SARS. And until we have that sort of information, it’s difficult to make any judgements.

Q. According to the latest figure you provided yesterday in China about the 1290 cases, 55 deaths and 1025 cured cases. In that case, only 110 cases left in China. Do you think that the figure may be a little bit misleading?

A. Dr Ryan:
These are the figures that are reported to us and clearly if there are cases in other parts of China that we’re not aware of, this figure may actually not reflect reality and that’s the issue that David mentioned. This represents Guangdong and I think the issue is now, how much disease is occurring in other provinces of China.

Dr Heymann:
And our team thinks that there is disease in most provinces.