Extrait du Quotidien du Peuple sur le coronavirus chez la civette et le raton laveur

Archives 12

Chinese scientists have traced the severe acute respiratory syndrome (SARS) virus back to a similar virus found in the civet cat and the raccoon dog, both animals found in the wild in China and elsewhere. Scientists have detected four isolates of a SARS-like coronavirus through a PT-PCR (reverse-transcription polymerase chain reaction) diagnostic test — which allows detection of the distinctive genetic information for SARS — from six Himalayan palm civets and a raccoon they took as samples from a market in Shenzhen in South China’s Guangdong Province on May 8. Guan Yi, a doctor at the University of Hong Kong’s Department of Microbiology, said: « We have charted a complete genetic map of the SARS-like coronavirus detected in the Himalayan palm civet, which shares 99.8 percent of the genetic code of the human SARS coronavirus. » According to the joint research by the University of Hong Kong and Shenzhen Centre for Disease Control and Prevention, there are only a minimal 80 differences in the 29,780 or so nuleotide and amino-acid substitutions between the coronavirus in humans and that in Himalayan palm civets, which are catlike mammals. Yuen Kwok-yung, head of microbiology at the university, said animals kept for food should be raised, slaughtered and sold with careful monitoring to prevent more outbreaks of SARS in people. However, officials with the National Headquarters for SARS Prevention and Control said earlier on Friday that they had not heard of the research results and declined to comment. The WHO announced in the Swiss city of Geneva that it had removed its travel warning for Hong Kong and Guangdong Province beginning on Friday this week, according to the Chinese Ministry of Health. The WHO said it took the decision because the SARS situation in these areas had improved significantly. On Thursday, the WHO proposed establishing a worldwide system for disease surveillance and response to fight SARS, including building epidemiology and public health laboratory facilities in China and the surrounding regions. The study by the University of Hong Kong linking civet cats to the coronavirus that causes SARS was described on Friday as a « significant breakthrough » by the World Health Organization. « If these findings are true, then this is a significant breakthrough, » Peter Cordingley, spokesman for the Manila-based WHO Western Pacific regional office, was quoted as saying in the Philippine Star online edition.

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Experts from the World Health Organization (WHO) welcomed the finding announced by Hong Kong scientists of possible cause of SARS virus from civet cats as « important, » according to news reaching here from the organization Saturday. WHO said the new finding would help direct future research into the virus. Scientists have been researching on the possible links between wild animals and the killer virus since the disease broke out. Francois Meslin, a WHO expert on diseases acquired from animals, told reporters the findings are « clearly quite exciting. » However, he also noted it is still too early to draw final conclusions on those findings. Meslin said it still cannot rule out the possibility the animals acquired the virus from humans, or that the virus jumped to humans from another animal altogether. Hours after WHO lifted the travel advisory against Hong Kong on Friday, scientists from the University of Hong Kong announced they had successfully isolated a type of coronavirus that causes SARS and it came from civet cats. Professor Yuen Kwok Yung, head of microbiology at the University of Hong Kong, said they believe the SARS virus jumped straight from civet cats to people. However, He also acknowledged they could not rule out the possibility other animals were involved in the transmission chain. Yuen’s team made the research in collaboration with the Center for Disease Control and Prevention of Shenzhen. They tested a large number of animals in south China’s Guangdong province, including civet cats, wild rabbits and barking deer, and found coronavirus in four masked palm civets. Civets, belonging to a large group of mostly nocturnal mammals, are not a true cat though they look like cats. The masked palm civets are one type of civets cats which have a white and black striped face. Yuen said it was important that the civet cats and other game food animals should be raised, slaughtered and sold under careful monitoring to prevent more outbreaks of SARS in people. « If you cannot control further jumping of such viruses from animals to humans, the same epidemic can occur again, » he said. Yuen’s team had previously said SARS came from animals but they had not been sure which kind. His team is the earliest in the world to identify that SARS virus is a type of coronavirus.

 

 

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Meeting on SARS virus detection and survival in food and water

Archive 11, Madrid, 8-9 May 2003 22 May 2003

Meeting on SARS virus detection and survival in food and water, Madrid, 8-9 May 2003 22 May 2003 Investigations of the global outbreak of SARS have shown that the major mode of transmission of the SARS virus is through close person contact, in particular exposure to droplets of respiratory secretions from an infected person. However, in a cluster of SARS cases in an apartment block in Hong Kong, sewage is believed to have played a role through droplets containing coronavirus from the sewage system. The World Health Organization sees the need for research to better define the modes of transmission of the SARS virus through sewage, faeces, food and water. The potential for infection by ingestion, in addition to the close person contact route, must also be considered. At a meeting in Madrid, May 8th – 9th 2003, WHO, in collaboration with FAO and OIE, brought together a group of concerned scientific experts who are ready to pursue this research agenda. The purpose was to gain a better understanding of how the SARS coronavirus survives in the environment, with particular reference to food, water, faeces and sewage. As a result, the group will work together in a research network, as part of the international effort to coordinate our collective understanding of the science of SARS and prevent it from becoming endemic. The proposed agenda for research covers standardized methods for isolation and quantification of the virus in the environment. Recommendations were also made for relevant studies on the resistance, persistence and inactivation of the virus under conditions commonly found in food and water processing as well as sanitation and sewage treatments. Investigation related to faecal-oral transmission would be precautionary in nature since there is no evidence or epidemiological indication that the virus can be transmitted through this route. Nevertheless the research network is looking into potential future scenarios and the research needs that would follow. The report of the first network meeting will soon be available on the WHO web site. As stated on 11 April 2003, WHO does not at present conclude that any goods, products or animals arriving from SARS-affected areas pose a risk to public health. WHO is actively pursuing further efforts to investigate and develop advice related to the prevention of SARS transmission. WHO is aware of and supports national efforts to ensure that good hygienic practices for food production is adhered to in SARS affected as well as in other areas. As with any infectious disease, an important general precautionary approach is to reinforce procedures relating to food worker hygiene, including active assessment for diseases.

 

 

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Nowhere to Find China’s First SARS Infected

Archive 10

Looking like a scene in a movie, all hopes have been focused upon ferreting out the first SARS infected in a dramatic way and then trace the origin of SARS virus. Although Severe Acute Respiratory Syndrome (SARS) first floated up in Foshan, it didn’t spread out there. Huang Xingchu, the first reported SARS case, has naturally become an important clue to this mysterious disease. However, he lost the sight from the horizon. Heyuan Center for Disease Control & Prevention Hopes to Find Huang Xingchu « We have been looking for him too, while we don’t know his whereabouts after he was discharged from hospital. » Said Mr. Fu Aifeng, deputy head with Heyuan Center for Disease Control and Prevention, denying that Huang Xingchu is now under the center’s protection. According to Huang’s own statement, he worked at a game restaurant.

Some experts from WHO therefore held that SARS virus was closely related to wildlife. Such a view almost became the verdict in the early stage when SARS broke out in Guangdong Province and judged by the fact that chefs made up the majority of SARS patients in Heyuan. However, among the SARS patients later reported in Guangdong their occupations had nothing to do with the wildlife. Mr. Fu Aifeng also acknowledged, « We thought so. But now it seems that the view is short of sufficient evidence. » Heyuan Center for Disease Control and Prevention hopes to find Huang Xingchu. « We are keeping in touch with Huang’s family so as to get to know his whereabouts. From the perspective of epidemiology or whatsoever, it is very important to find him. He’d better have further consultation with doctors. » « Besides, we have to be responsible for Shenzhen. For instance, which restaurant has Huang Xingchu ever worked in? Is there anyone else who’s contracted SARS but did not exhibit the symptoms? » « We have nowhere to find him now. We neglected the importance, but when we realized it, he disappeared. »

« Mysterious Disease » Brought about Pressure to Patients In regard to Huang Xingchu’s disappearance, Mr. Fu Aifeng gave a relatively convincible account: due to this mysterious disease, Huang’s whole family was isolated in the countryside. As a matter of fact, no one would like to let others know. « Since contracting SARS, the patient has to bear huge social pressure. This calls for understanding of the society. » « We will make an investigation of the patients in respect of epidemiology. » And so, « everybody is looking for Huang Xingchu. » By April 30 when Heyuan’s last SARS patient was cured and discharged from hospital, Heyuan had a total of 19 SARS cases, including 9 medical workers while no death. On May 2, Heyuan’s last suspected case was ruled out. « Up to now there hasn’t been any SARS patient for a week in Heyuan, » said Mr. Fu Aifeng with gratification. Although nearly half a year has passed since the first report of the SARS case, the world has so far witnessed no progress concerning the origin of the SARS virus. Even if Huang Xingchu were found, no problem would be solved in any practical sense, because nobody has been infected except the medical workers. How on Earth Are People Infected with SARS Virus? In an interview, a staff member of Guandong Center for Disease Control and Prevention said, « All agencies for disease control and prevention have been working deep into the night. All others except those engaged in disease control and prevention have been out for investigation, but no advancement has yet been made. » « We still have no idea about what kind of virus it is, how it infects people and where it comes from. » « Experts from WHO are also here together with us. Maybe we will find the answer soon, maybe not forever. » There are too many doubts as to the outspread of SARS in China. Academician Zhong Nanshan pointed out especially on TV that 96 percent of the SARS patients in the Chinese mainland didn’t come into contact with SARS infection. In other words, unlike other countries and regions such as Hong-Kong and Singapore where there are infectious chains, the majority of Chinese SARS patients caught the virus in an unaccountable way. There were no intimate contacts between patients. Moreover, patients are concentrated in Guangdong and Beijing.

It is not imposable that diseases emerge in cities, considering cities have dense population and henceforth virus spreads fast there. The spread of SARS depends on whether it is ventilated. Before we get a clear understanding of the disease, it is still too early to jump to the conclusion about the SARS in China.

By PD Online Staff Zhu Lizhen

 

 

 

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F.A.O. Lundi 5 mai 2003

Archives 09

FAO Organisation des Nations Unies pour l’Alimentation et l’Agriculture

Interview de Peter Roeder, spécialiste de la santé animale à la FAO

La propagation du Syndrome respiratoire aigu sévère (SRAS) a soulevé une inquiétude planétaire. Certains médias ont émis l’hypothèse selon laquelle l’élevage intensif pourrait être un foyer du virus. Peter Roeder, de la Division de la production et de la santé animales de la FAO, commente le lien possible entre l’agriculture, l’élevage et la pandémie de Sras.

Y-a-t-il des preuves que le virus du SRAS provienne des animaux?

Il n’y a aujourd’hui aucune preuve permettant d’imputer l’origine du virus aux animaux d’élevage (boeufs, cochons, volaille, etc) et cela semble improbable, même si l’origine du virus est toujours un mystère. En admettant que le SRAS soit causé par le nouveau coronavirus qui a été associé à la maladie, la prise d’empreinte génétique de ce virus montre qu’il ne ressemble à aucun coronavirus animal ou humain connu.

Y-a-t-il un lien quelconque entre le SRAS et la « grippe du poulet » qui sévit actuellement en Europe et aux USA?

Non, ces deux maladies sont causées par deux virus complètement différents. Peut-on accuser l’élevage intensif et la concentration d’animaux d’être des foyers du virus? Instinctivement, on pourrait penser que c’est le cas, mais comme il n’y a aucune preuve que le virus provienne des animaux d’élevage, ces facteurs ne peuvent pas être tenus pour responsables dans cette affaire. L’importante densité de population dans la Chine méridionale aurait pu tout aussi bien être un facteur important dans la genèse de cette maladie, quelle que soit son origine.

Une production animale plus «durable» pourrait-elle réduire les risques de telles maladies?

Certainement, mais ce n’est pas de cela dont il s’agit dans cette affaire. Ceci dit, il est de plus en plus démontré que les systèmes de production animale intensifs et industrialisés sont vulnérables aux épizooties. Cela jette le doute sur la viabilité de ces systèmes. La promiscuité des humains avec plusieurs espèces d’animaux élevés de manière intensive peut fournir un substrat pour une transmission entre les espèces, l’évolution et l’amplification de plusieurs agents pathogènes.

Des scientifiques au Canada et en Australie projettent d’importer le virus du SRAS pour l’inoculer à des animaux. La FAO soutient ces expériences. Qu’en attendez-vous ?

Ce travail expérimental est nécessaire afin d’accorder les études de terrain pour examiner l’improbable circulation du virus dans les populations animales. Le travail a déjà commencé au Centre national canadien des maladies animales exotiques et nous espérons qu’il sera complété par d’autres études menées en Australie. Nous nous attendons à ce que ce travail nous en dise plus sur la capacité du virus d’infecter les animaux, la nature de tout signe de la maladie et la probabilité que les animaux transmettent le virus. Le virus peut-il être transmis par les produits animaux et le commerce? Nous ne disposons d’aucune preuve que le virus du SRAS infecte les animaux d’élevage et, par conséquent, sa présence dans les produits animaux et les produits alimentaires n’est que spéculation. Même s’il était présent, le virus serait probablement complètement détruit lors de la cuisson et la transformation. Les coronavirus, auxquels l’agent infectieux du SRAS appartient probablement, ont tendance à être très fragiles hors du corps animal et auraient une durée de vie très courte – quelques heures – en tant que résidus du conditionnement des aliments. Il n’y aucune raison de penser que le commerce des animaux ait été la voie de propagation de la maladie dans les zones affectées et autour du monde. Tout montre que le virus est un pathogène humain transmis principalement à partir de gouttelettes émises par les voies respiratoires des personnes malades. Les restrictions commerciales pourraient-elles aider à enrayer la propagation du virus? Le commerce ne semble pas jouer un rôle, des restrictions en ce sens ne seraient donc pas pertinentes.

Est-ce que le virus pourrait être véhiculé par les produits alimentaires transportés par les voyageurs?

Ici encore, la réponse semble être clairement « non ».

Quel est le rôle de la FAO dans la lutte contre le SRAS?

Il importe avant tout à la FAO qu’une caractérisation complète et parfaite de l’agent du SRAS et de son évolution soit réalisée. L’implication des animaux d’élevage et du commerce doit être exclue. En partenariat avec l’OMS, la FAO suit tout particulièrement le contexte d’exploitation et de manipulation des aliments. De manière générale, l’évolution des agents pathogènes dans les systèmes agricoles intensifs dans les zones très peuplées est, pour elle, un souci permanent. Comprendre l’évolution des pathogènes en relation avec les systèmes de production et la chaîne alimentaire est un composant essentiel du travail de la FAO en santé vétérinaire.

 

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Réunion de Toronto du 30 avril Jeudi 1er mai 2003

Archive 08

Le problème actuel du coronavirus : avoir le SRAS sans le coronavirus ? avoir le coronavirus sans le SRAS.

Des tests canadiens de dépistage du coronavirus ont été positifs chez des personnes sans le SRAS. Le Laboratoire National de Microbiologie Canadien à Winnipeg a constaté la présence du coronavirus chez 14% des 550 personnes qui étaient sous observation pour le SRAS mais dont l’état n’a jamais correspondu aux critères de définition des cas de pneumonie atypique.

Le Dr Frank Plummer, directeur scientifique du laboratoire ajoute que certains avaient été exposés à un cas de pneumonie atypique ou avaient voyagé dans des régions infectées mais d’autres pas.

Il fait partie des personnes qui doutent que le coronavirus est responsable du SRAS contrairement à l’OMS ou au CDC d’Atlanta.

De plus le Laboratoire ne trouve la trace du virus que dans environ 40% des Canadiens diagnostiqués comme des cas probables et dans 30% des cas suspects.

Il comprend encore moins le groupe des 14% indiqué plus haut.

Le Dr Stephen Ostroff du CDC admet que les résultats de tests effectués par son organisme s’avèrent également troublants : sur 20 cas probables et 40 cas suspects de SRAS, le coronavirus n’ést présent que dans six des cas probables et aucun des cas suspects… (affaire à suivre)

 

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SARS and Genetic Engineering?

The complete sequence of the SARS virus is now available, confirming it is a new coronavirus unrelated to any previously known. Has genetic engineering contributed to creating it? Dr. Mae-Wan Ho and Prof. Joe Cummins call for an investigation. The World Health Organisation, which played the key role in coordinating the research, formally announced on 16 April that a new pathogen, a member of the coronavirus family never before seen in humans, is the cause of Severe Acute Respiratory Syndrome (SARS). « The pace of SARS research has been astounding, » said Dr. David Heymann, Executive Director, WHO Communicable Diseases programmes. « Because of an extraordinary collaboration among laboratories from countries around the world, we now know with certainty what causes SARS. » But there is no sign that the epidemic has run its course. By 21 April, at least 3 800 have been infected in 25 countries with more than 200 dead. The worst hit are China, with 1 814 infected and 79 dead, Hong Kong, 1 380 infected and 94 dead, and Toronto, 306 infected, 14 dead. A cluster of SARS patients in Hong Kong with unusual symptoms has raised fears that the virus may be mutating, making the disease more severe. According to microbiologist Yuen Kwok-yung, at the University of Hong Kong, the 300 patients from a SARS hot spot, the Amoy Gardens apartment complex, were more seriously ill than other patients: three times as likely to suffer early diarrhoea, twice as likely to need intensive care and less likely to respond to a cocktail of anti-viral drugs and steroids. Even the medical staff infected by the Amoy Gardens patients were more seriously ill. John Tam, a microbiologist at the Chinese University of Hong Kong studying the gene sequences from these and other patients suspects a mutation leading to an altered tissue preference of the virus, so it can attack the gut as well as the lungs. The molecular phylogenies published 10 April in the New England Journal of Medicine were based on small fragments from the polymerase gene (ORF 1b) (see Box), and have placed the SARS virus in a separate group somewhere between groups 2 and 3. However, antibodies to the SARS virus cross react with FIPV, HuCV229E and TGEV, all in Group 1. Furthermore, the SARS virus can grow in Vero green monkey kidney cells, which no other coronavirus can, with the exception of porcine epidemic diarrhea virus, also in Group 1. Coronaviruses Coronaviruses are spherical, enveloped viruses infecting numerous species of mammals and birds. They contain a set of four essential structural proteins: the membrane (M) protein, the small envelope (E) protein, the spike (S) glycoprotein, and the nucleocapside (N) protein. The N protein wraps the RNA genome into a ‘nucleocapsid’ that’s surrounded by a lipid membrane containing the S, M, and E proteins. The M and E proteins are essential and sufficient for viral envelope formation. The M protein also interacts with the N protein, presumably to assemble the nucleocapsid into the virus. Trimers (3 subunits) of the S protein form the characteristic spikes that protrude from the virus membrane. The spikes are responsible for attaching to specific host cell receptors and for causing infected cells to fuse together. The coronavirus genome is a an infectious, positive-stranded RNA (a strand that’s directly translated into protein) of about 30 kilobases, and is the largest of all known RNA viral genomes. The beginning two-thirds of the genome contain two open reading frames ORFs, 1a and 1b, coding for two polyproteins that are cleaved into proteins that enable the virus to replicate and to transcribe. Downstream of ORF 1b are a number of genes that encode the structural and several non-structural proteins. Known coronaviruses are placed in three groups based on similarities in their genomes. Group 1 contains the porcine epidemic diarrhea virus (PEDV), porcine transmissible gastroenteritis virus (TGEV), canine coronavirus (CCV), feline infectious peritonitis virus (FIPV) and human coronovirus 229E (HuCV229E); Group 2 contains the avian infectious bronchitis virus (AIBV) and turkey coronavirus; while Group 3 contains the murine hepatitis virus (MHV) bovine coronavirus (BCV), human coronavirus OC43, rat sialodacryoadenitis virus, and porcine hemagglutinating encephomyelitis virus. Where does the SARS virus come from? The obvious answer is recombination, which can readily occur when two strains of viruses infect a cell at the same time. But neither of the two progenitor strains is known, says Luis Enjuanes from the Universidad Autonoma in Madrid, Spain, one of the world leaders in the genetic manipulation of coronaviruses. Although parts of the sequence appeared most similar to the bovine coronavirus (BCV) and the avian infectious bronchitis virus (AIBV) (see « Bio-Terrorism & SARS », this series), the rest of the genome appear quite different. Could genetic engineering have contributed inadvertently to creating the SARS virus? This point was not even considered by the expert coronavirologists called in to help handle the crisis, now being feted and woed by pharmaceutical companies eager to develop vaccines. A research team in Genomics Sciences Centre in Vancouver, Canada, has sequenced the entire virus and posted it online 12 April. The sequence information should now be used to investigate the possibility that genetic engineering may have contributed to creating the SARS virus. If the SARS virus has arisen through recombined from a number of different viruses, then different parts of it would show divergent phylogenetic relationships. These relationships could be obscured somewhat by the random errors that an extensively manipulated sequence would accumulate, as the enzymes used in genetic manipulation, such as reverse transcriptase and other polymerases are well-known to introduce random errors, but the telltale signs would still be a mosaic of conflicting phylogenetic relationships, from which its history of recombination may be reconstructed. This could then be compared with the kinds of genetic manipulations that have been carried out in the different laboratories around the world, preferably with the recombinants held in the laboratories. Luis Enjuanes’ group succeeded in engineering porcine transmissible gastroenteritis virus, TGEV, as an infectious bacterial artificial chromosome, a procedure that transformed the virus from one that replicates in the cytoplasm to effectively a new virus that replicates in the cell nucleus. Their results also showed that the spike protein (see Box) is sufficient to determine its disease-causing ability, accounting for how a pig respiratory coronavirus emerged from the TEGV in Europe and the US in the early 1980s. This was reviewed in an earlier ISIS report entitled, « Genetic engineering super-viruses » (ISIS News 9/10, 2000), which gave one of the first warnings about genetic engineering experiments like these. The same research group has just reported engineering the TGEV into a gene expression vector that still caused disease, albeit in a milder form, and is intending to develop vaccines and even human gene therapy vectors based on the virus. Coronaviruses have been subjected to increasing genetic manipulation since the late 1990s, when P.S. Masters used RNA recombination to introduce changes into the genome of mouse hepatitis virus (MHV). Since then, infectious cDNA clones of transmissible TGEV, human coronavirus (HuCV), AIBV and MHV have all been obtained. In the latest experiment reported by Peter Rottier’s group in University of Utrecht, The Netherlands, recombinants were made of the feline infectious peritonitis virus (FIPV) that causes an invariably lethal infection in cats. The method depends on generating an interspecies chimeric FIPV, designated mFIPV, in which, part of its spike protein has been substituted with that from mouse virus, MHV, as a result, the mFIPV infects mouse cells but not cat cells. When synthetic RNA carrying the wild-type FIPV S gene is introduced into mFIPV-infected cells, recombinant viruses that have regained the wild type FIPV S gene will be able to grow in cat cells, and can hence be selected. So any mutant gene downstream of the site of recombination, between ORF 1a and ORF1b (see Box), can be successfully introduced into the FIPV. This method was previously used to introduce directed mutations into MHV, and like the experiment just described, was carried out to determine the precise role of different genes in causing disease. This targeted recombination is referred to as ‘reverse genetics’, and depends on the virus having a very narrow host range determined by the spike protein in its coat. Another research team headed by P. Britten based in the Institute of Animal Health, Compton Laboratory, in the United Kingdom, has been manipulating AIBV, also in order to create vectors for modifying coronavirus genomes by targeted recombination, a project funded by the UK Ministry of Agriculture, Fisheries and Food and the Biotechnology and Biological Sciences Research Council (BBSRC). The procedure involved infecting Vero cells, a green monkey kidney cell line with recombinant fowlpox virus (rFPV-T7) – carrying an RNA polymerase from the T7 bacteriophage, with a promoter from the vaccinia virus – together with AIBV, and a construct of a defective AIBV genome in rFPV that can be replicated in Vero cells. Recombinant cornonaviruses with defective AIBV genomes were recovered from the monkey cells. This is significant because almost no natural coronaviruses are able to replicate in Vero cells; the researchers have created a defective virus that can do so, when a helper virus is present. The defective virus has the potential to regain lost functions by recombination. In addition to the experiments described, the gene for the TGEV spike protein has been engineered into and propagated in tobacco plants, and Prodigene, a company specializing in crop biopharmaceuticals, has produced an edible vaccine for TGEV in maize. Information on whether or not that product was the one being field tested in a recent case of contamination reported by the USDA was withheld under ‘commercial confidentiality’. Sources & References « Coronavirus never before seen in humans is the cause of SARS. Unprecedented collaboration identifies new pathogen in record time » WHO Press Release, 16 April 2003, Geneva thompsond@who.int BBC Radio 4 News Report, 19-21 April 2003. « China says Sars outbreak is 10 times worse than admitted » by John Gittings and Jame Meikle, The Guardian 21 April 2003. « Chinese cover-up creates new sense of insecuirity in face of Sars epidemic » by John Gittings, The Guardian 21 April 2003. « SARS virus is mutating, fear doctors » by Debora MacKenzie, 16 April 2003, NewScientist.com news service. Ksiazeh TC, Erdman D, Goldsmith C et al. A novel coronavirus associated with severe acute respiratory syndrome. NEJM online www.nejm.org 10 April, 2003. Drosten C, Gunther S, Preiser W et al. Identification of a novel coronavirus in patients with acute respiratory syndrome. NEJM online www.nejm.org 10 April, 2003. « Calling all coronavirologists » by Martin Enserik, Science 18 April 2003. Lai MMC. The making of infectious viral RNA: No size limit in sight. PNAS 2000: 97: 5025-7. Almazan F, Gonsalex JM, Penzes Z, Izeta , Calvo E, Plana-Duran J and Enjuanes. Engineering the largest RNA virus genome as an infectious bacterial artificial chromosome. PNAS 2000: 97: 5516-21. Ho MW. Genetic engineering super-viruses. ISIS News 9/10 , July 2001, ISSN: 1474-1547 (print), ISSN: 1474-1814 (online). Sola I, Alonso S, Zúñiga S, Balasch M, Plana-Durán J and Enjuanes L. Engineering the transmissible gasteroenteritis virus genome as an expression vector inducing lactogenic immunity. J. Virol. 2003, 77, 4357-69. Masters PS. Reverse genetics of the largest RNA viruses. Adv. Virus Res. 1999, 53, 245-64. Haijema, B.J., Volders, H. & Rottier, P.J.M. Switching species tropism: an effective way to manipulate the feline coronavirus genome. Journal of Virology 2003, 77, 4528 – 38. Kuo L, Godeke GJ, Raamsman MJ, Masters PS and Rottier PJ. Retargeting of coronavirus by substitution of the spike glycoprotein ectodomain: crossing the host cell species barrier. J. Virol. 2000, 74, 1393-1406. Evans S, Cavanagh D and Britten P. Utilizing fowlpox virus recombinants to generate defective RNAs of the coronavirus infectious bronchitis virus. J. Gen. Virol. 2000, 81, 2855-65. Tubolya T, Yub W, Baileyb A, Degrandisc S, Dub S, Erickson L and Nagya EÂ. Immunogenicity of porcine transmissible gastroenteritis virus spike protein expressed in plants.Vaccine 2000, 18, 2023-8. Prodigene, http://www8.techmall.com/techdocs/TS000215-6.html Sept 2001. « Pharmageddon » by Mae-Wan Ho, Science in Society 2003, 17 , 23-4.

 

 

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WHO biosafety guidelines for handling of SARS specimens

Archives 06 - 25 April 2003

The following biosafety guidelines have been prepared by WHO for handling clinical specimens associated with SARS. SARS specimens should be handled according to appropriate biosafety practices in order to avoid laboratory-related infections and spread of disease to close contacts. As the primary route of infection is thought to be via droplets, extreme caution must be exercised to eliminate the unguarded production of aerosols. Detailed information about containment facilities and biosafety practices recommended in this document may be found in the WHO Laboratory Biosafety Manual, 2nd revised edition, available from the WHO web site . According to the latest findings, the etiologic agent responsible for the syndrome is a previously unknown coronavirus, currently called SARS coronavirus, or SARS-CoV . Accordingly, all laboratory work practices should be appropriate for work with viral agents, with particular emphasis on potential spread by droplets, air, and/or contaminated surfaces and objects. No procedure should be undertaken in which there is any doubt about the ability to adequately contain the specimen and prevent the uncontrolled release of the virus. WHO biosafety guidelines for handling SARS clinical specimens and materials derived from laboratory investigations of SARS: The following activities may be performed in biosafety level 2 (BSL-2) facilities with appropriate BSL-2 work practices: Routine diagnostic testing of serum and blood samples Manipulations involving known inactivated (lysed, fixed or otherwise treated) virus particles and/or incomplete, non-infectious portions of the viral genome Routine examination of mycotic and bacterial cultures. Final packaging of specimens for transport to diagnostic laboratories for additional testing. Specimens should already be in a sealed, decontaminated primary container The following precautions are strongly recommended by WHO for work in BSL-2 laboratories with potential SARS specimens: Any procedure that may generate aerosols should be performed in a biological safety cabinet. Laboratory workers should wear protective equipment, including disposable gloves, solid-front or wrap-around gowns with cuffed sleeves, eye protection and a surgical mask, or full-face shield, according to the risk of aerosols and exposure when performing specific manipulations. When working at a biological safety cabinet, a full face shield is not necessary. Centrifugation of human specimens should be performed using sealed centrifuge rotors or sample cups. These rotors or cups should be unloaded in a biological safety cabinet. Procedures performed outside of a biological safety cabinet should be performed in a manner that minimizes the risk of exposure to an inadvertent release of the etiologic agent. Work surfaces and equipment should be decontaminated after specimens are processed. Standard decontamination agents that are effective against lipid-enveloped viruses should be sufficient. Biological waste should be treated as outlined in the WHO Laboratory Biosafety Manual, 2nd revised edition which renders viral particles inactive. In cases where laboratory facilities are marginal, consideration should be given to referral of specimens to a suitably equipped reference laboratory for primary diagnostic tests. The following activities require BSL-3 facilities and BSL-3 work practices. Viral cell culture of the etiologic agent. Manipulations involving growth or concentration of the etiologic agent. When a procedure or process cannot be conducted within a biological safety cabinet, then appropriate combinations of personal protective equipment (e.g., respirators, face shields) and physical containment devices (e.g., centrifuge safety cups or sealed rotors) must be used. The following activities require Animal BSL-3 facilities and Animal BSL-3 work practices: Inoculation of animals for potential recovery of the agent from SARS samples. Any protocol involving animal inoculation for confirmation and/or characterization of putative SARS agents. Transport of human specimens: Transport of specimens within national borders should comply with current national regulations. International air transport of human specimens from suspect or confirmed SARS cases must follow the current (2003) edition of the International Air Transport Association (IATA) Dangerous Goods Regulations.

- Dangerous goods index

- Consignment of diagnostic

specimens 2003 Current IATA regulations (2003) allow specimens known or suspected of containing the SARS agent to be transported as UN 3373 “Diagnostic Specimens” when they are transported for diagnostic or investigational purposes. Specimens transported for any other purposes must be transported as UN 2814, and marked as: “Infectious substance, affecting humans (Severe Acute Respiratory Syndrome virus)”. Cultures prepared for the deliberate generation of pathogens may not be transported as diagnostic specimens, but as UN 2814, Infectious Substance, affecting humans (Severe Acute Respiratory Syndrome virus). All specimens to be transported (UN 3373 or UN 2814) must be packaged in triple packaging consisting of three packaging layers: UN 3373, Diagnostic Specimens, shall be packed in good quality packagings, which shall be strong enough to withstand the shocks and loads normally encountered during transport.

Packagings shall be constructed and closed so as to prevent any loss of contents that might be caused under normal conditions of transport, by vibration or by changes in temperature, humidity or pressure. Primary receptacles shall be packed in secondary packagings in such a way that, under normal conditions of transport, they cannot break, be punctured or leak their contents into the secondary packaging. Secondary packagings shall be placed in a final outer package with suitable cushioning material. Any leakage of the contents shall not substantially impair the protective properties of the cushioning material or of the outer packaging.

For Liquids

The primary receptacle(s) shall be leakproof and shall not contain more than 500 mI. There shall be absorbent material placed between the primary receptacle and the secondary packaging; if several fragile primary receptacles are placed in a single secondary packaging, they shall be either individually wrapped or separated so as to prevent contact between them. The absorbent material shall be in sufficient quantity to absorb the entire contents of the primary receptacles and there shall be a secondary packaging which shall be leakproof. The primary receptacle or the secondary packaging shall be capable of withstanding without leakage an internal pressure producing a pressure differential of not less than 95 kPa (0.95 bar). The outer packaging shall not contain more than 4 litres.

For Solids

The primary receptacle(s) shall be siftproof and shall not contain more than 500 g. If several fragile primary receptacles are placed in a single secondary packaging, they shall be either individually wrapped or separated so as to prevent contact between them and there shall be a secondary packaging which shall be leakproof. The outer packaging shall not contain more than 4 kg.

For air transport, the smallest overall external dimension of a completed package must be at least 10 mm. Packaging must conform to certain performance standards. For further information about definitions, packaging requirements, markings and labels, accompanying documentation, and refrigerants, please refer to the competent authority, current IATA shipping guidelines, commercial packaging suppliers, or available courier companies.

 

 

 

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Tableau des Provinces chinoises au 30 Avril 2003

Tableau des Provinces chinoises au 30 Avril 2003

Region Confirmed Recovered Deaths Suspected
Anhui 7 - - 2
Beijing 1440(255)* 90 75 1408
Chongqing - - - 6
Fujian 3 1 - -
Gansu 3 - 1 3
Guangdong 1405(342) 1201 51 169
Guangxi 18 8 3 2
Guizhou - - - -
Hainan - - - -
Hebei 48(7) - 4 67
Heilongjiang - - - 2
Henan 12(1) - - 16
Hubei 3(1) - - 15
Hunan 6 5 1 4
Inner Mongolia 127(16) 2 9 220
Jiangsu 1 - - 3
Jiangxi - - - 2
Jilin 7(2) - - 3
Liaoning 1 - - 4
Ningxia 5 - 1 5
Qinghai - - - -
Shaanxi 8 - - 26
Shandong 1 - - 1
Shanghai 2 0 0 7
Shanxi 299(62) 22 9 130
Sichuan 12 3 2 21
Tianjin 49(23) - 3 81
Tibet - - - -
Xinjiang - - - 1
Yunnan - - - -
Zhejiang 3 - - 5
Yunnan - - - -
Total 3460(709) 1332 159 2203

*Numbers in the brackets refer to cases among medical staff.

 

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Une hypothèse de traitement

Archives 03

SARS: An hypothesis for treatment

Fc Receptors Leukocyte Fc receptors (FcR) are cell surface glycoproteins that bind the Fc portion of immunoglobulin (Ig), thereby linking antigen recognition by antibodies with cell-based effector mechanisms. Fc receptors for IgG expressed on macrophages and NK cells are important mediators of opsonophagocytosis and Ab-dependent cell-mediated cytotoxicity. Fc receptor-mediated phagocytosis plays a pivotal role in clearance of respiratory virus infections [1]. Influenza A virus infection, for example, induces cross-reactive antibodies that enhance uptake of virus into Fc receptor-bearing cells [2]. Some complex viruses (e.g. Poxviruses, Herpesviruses) may have more than one receptor/receptor-binding protein, therefore, there may be alternative routes of uptake into cells. Specific receptor binding can be side-stepped by antibody-coated virus particles binding to Fc receptor on the surface of monocytes, which results in virus uptake [3]. The expression (or absence) of receptors on the surface of cells largely determines the TROPISM of most viruses, i.e. the type of cell in which they are able to replicate – important factor in pathogenesis. Attachment is in most cases a reversible process – if penetration does not ensue, the virus can elute from the cell surface. Some viruses have specific mechanisms for « detachment » e.g. Influenza neuraminidase protein. BUT: elution from cell often leads to changes in the virus that decrease or eliminate the possibility of attaching to other cells. SARS coronavirus The SARS coronavirus is a single-stranded positive (+) sense RNA virus. Polycistronic mRNA, e.g. Picornaviruses and the Flavivirus « Yellow fever virus » (hemorrhagic fever) are also Ssrna+ viruses. The genome RNA of the virus is the mRNA. Translation of the mRNA into DNA results in the formation of a polyprotein product, which is subsequently cleaved to form the mature proteins. [3]. Antibodies and viral infections and Fc Receptors Specific antibodies are important in and may protect against viral infections. The most effective type of antiviral antibody is « neutralizing » antibody – this is antibody which binds to the virus, usually to the viral envelope or capsid proteins, and which blocks the virus from binding and gaining entry to the host cell. Virus specific antibodies may also act as opsonins in enhancing phagocytosis of virus particles – this effect may be further enhanced by complement activation by antibody-coated virus particles. In addition, in the case of some viral infections, viral proteins are expressed on the surface of the infected cell. These may act as targets for virus-specific antibodies, and may lead to complement-mediated lysis of the infected cell, or may direct a subset of natural killer cells to lyse the infected cell through a process known as antibody-directed cellular cytotoxicity (ADCC). At mucosal surfaces (such as the respiratory and gastrointestinal tracts), virus infection may induce the production of specific antibodies of the IgA isotype, which may be protective against infection at these surfaces. (This is the basis of immunisation with the current oral polio vaccine) [4]. Not all antibodies to viruses are protective, however, and in certain cases antibody to the virus may facilitate its entry into a cell through Fc receptor-mediated uptake of the antibody coated particle. Such antibodies are called enhancing antibodies. Non-neutralizing antibody has been shown to enhance the virulence of the alpha and flaviviruses by promoting their binding to FC receptors [5]. In murine hepatitis virus, MHV S peplomer protein exhibits Fc IgG binding ability. The SARS coronavirus appears very similar to the murine hepatitis virus though they are not the same [6]. Antigenic variation among murine coronaviruses is associated primarily with the surface peplomer protein E2 (180,000 Da). E2 is responsible for attachment of the virus to the host cell, MHV-induced cell fusion, and eliciting neutralizing antibody. Molecular mimicry exists between E2 and Fc gamma receptor (Fc gamma R) [7]. MHV S peplomer protein expressed by a recombinant vaccinia virus vector exhibits IgG Fc-receptor activity [8]. Polymorphisms of Fc receptors for IgG (Fc gamma R) have been proposed as a genetic factor that influences susceptibility for the human disease, systemic lupus erythematosus (SLE) [9]. Allelic variants of Fc gamma R confer distinct phagocytic capacities providing a mechanism for heritable susceptibility to immune complex disease. Human Fc gamma RIIa has two codominantly expressed alleles, R131 and H131, which differ substantially in their ability to ligate human IgG2. The Fc gamma RIIa-H131 is the only human Fc gamma R which recognizes IgG2 efficiently and optimal IgG2 handling occurs only in the homozygous state [10]. Trend analysis of the genotype distribution showed a highly significant decrease in Fc gamma RIIA-H131 as the likelihood for lupus nephritis increased (P = 0.0004) consistent with a protective effect of the Fc gamma RIIA-H131 gene. The skewing in the distribution of Fc gamma RIIA alleles identifies this gene as a risk factor with pathophysiologic importance for the SLE diathesis in African Americans [11]. An abnormal distribution of Fc gammaRIIa polymorphisms was associated with SLE in Korean patients [12]. One hundred eight Caucasian patients were diagnosed with SLE according to the American College of Rheumatology criteria. The SLE patients and 187 Caucasian controls were genotyped for the FcgammaRIIa polymorphism, and associations between FcgammaRIIa genotypes, selected HLA haplotypes, and clinical as well as laboratory features were analyzed. Results indicated no significant skewing of the FcgammaRIIa polymorphism was observed in the SLE Caucasian cohort. The FcgammaRIIa polymorphism constitutes an additional factor that might influence the clinical manifestations and course of SLE, but does not represent a genetic risk factor for the occurrence of SLE [13]. We see, in the above information, that there appears to be some differences in ethnic groups relative to Fc receptors for IgG. In Systemic Lupus Erythematosus we see skewed Fc receptors for IgG in Africans and Asians but not in Caucasians. You will recall that Fc receptors are cell surface glycoproteins that bind the Fc portion of immunoglobulin (Ig), thereby linking antigen recognition by antibodies with cell-based effector mechanisms. Yap (1999) found in their studies, « based on 175 Chinese and 50 Malays SLE patients as well as 108 and 50 ethnically (Chinese and Malays), matched healthy controls for the respective groups in examining Fc Gamma Receptors relative to Lupus (SLE). Analysis of the data (chi2 test with Yates correction factors and odds ratios) revealed that there were no significant differences between SLE patients and controls. We have not found evidence of a protective effect conferred by FcgammaRIIA-H131 in the ethnic groups studied » [14]. Fcgamma receptors (FcgammaRs) are potent initiators of proinflammatory reactions and tissue injury programs through the oxidative burst, degranulation and the production of a variety of proinflammatory cytokines. The well-characterized and functionally important alleles of neutrophil FcgammaR (FcgammaRIIa-H131/R131 and FcgammaRIIIb-NA1/NA2) are possible inheritable genetic elements that may alter disease severity and/or phenotype [15]. Work like this has also been directed toward determining differences between and among, for example, Ethiopians and Norwegians with the observation that « The variation of different polymorphisms both within and between ethnic groups may influence differences in the incidence rates of infectious and autoimmune diseases » [16]. So then, if there are ethnic differences relative to the Fc gamma Receptors associated with IgG and incidence of infectious and autoimmune diseases, might this serve as a basis whereby it might be possible to understand SARS? Let’s consider the situation in SARS coronavirus and the currently developing pandemic. At this point, there have been over a thousand Chinese infected with SARS and the mortality rate hovers around 5% of that population. In contrast, Caucasian-predominate nations have very few cases of SARS and, for example, in the United States no one has died from SARS. While the disease is not widely spread in Caucasian countries at this time (those infected in Toronto are predominately Chinese), there may be some reason to consider ethnicity and differential immune-system functioning in response to disease. Might this difference in ethnicity-number-dead-and-infected be a function of an « influencing of differences in the incidence rates of infectious and autoimmune diseases » suggested above? This might depend on whether SARS coronavirus activates Fc gamma Receptors in Asian and Africans who may have a disproportionate proinflammatory reaction to SARS. This remains to be seen as the science progresses. However, we might expect that this potent proinflammatory reaction might be due to the SARS coronavirus and perhaps this potent proinflammatory rection is associated with Fc gamma Receptors. It is a theory worth investigating. Untried Treatments for SARS? As indicated above, the coronaviruses related to SARS coronavirus display an « S peplomer protein » that mimicks Fc receptors and the E2 glycoprotein of Murine hepatitis virus, for example, displays Fc receptor-like activity. Perhaps if there was a way to prevent the « potent proinflammatory response » induced by SARS, a therapeutic treatment may be offered to those in whom the Fc gamma Receptor triggers a profound proinflammatory response. Work suggests that nitric oxide may function in an anti-inflammatory capacity by down-regulating endotoxin-stimulated cytokine production by alveolar macrophages and matured monocytes [17]. Use of a treatment that would prevent the cascade of pro-inflammatory cytokines might prevent further virus uptake and more serious disease as well as offer a treatment for the initial infection itself. There are other anti-inflammatory interventions. Various efforts to develop cytokine-blocking have been undertaken. Cunard (2002) discusses regulation of cytokine expression by ligands of peroxisome proliferator activated receptors [18]. N-formylmethionylleucylphenylalanine has also been used to inhibit Fc gamma Receptor-dependent functions [19]. Currently, treatments for SARS patients include administration of steroids and ribavirin in China with, as of 4/20/03, questions about the efficacy of such treatments as the number of SARS dead increases in China. There has been nothing stated in any publicly available resource – medical journals, news reports, or elsewhere – of which I am aware of the use of Fc gamma receptor inhibitors / cytokine inhibitors / pro-inflammatory inhibitors (beyond the use of steroids). It is my suggestion, based on the above information, awareness of the construction of the virus, and many other factors, that consideration be given for treatment of SARS-infected patients which includes: · Fc gamma Receptor inhibitors · Cytokine inhibitors · Pro-inflammatory inhibitors Possibly there may even be value in the use of immune-system suppression in the treatment of those with the most serious cases of SARS where death-without-a-miracle is impending. To summarize all of the above data in a few paragraphs, it is my hypothesis that SARS provokes a profound proinflammatory response in infected individuals. Individuals who are suspectible to this type of response, i.e., ethnicities previously noted, may react to SARS coronavirus infection in a cascade of events which generally would include more Fc gamma receptor being produced which leads to more virus being uptaken which leads to more proinflammation which leads to more Fc gamma receptor being produced, etc. in a fatal feedback loop of the immune system. Treatment of SARS for these individuals might require breaking this feedback loop of the immune system through (a) inhibiting Fc gamma receptors, (b) inhibiting cytokine production, (c) inhibiting proinflammatory responses, and, perhaps, in extreme cases, (d) inducing immune-system suppression. Theory developed by: Robert E. Lee, M.S., M.S.W., L.C.S.W. April 20, 2003 Apologies to those below whom I have quoted liberally… REFERENCES: [1] HUBER VC, Lynch JM, Bucher DJ, Le J, Metzger DW. Fc receptor-mediated phagocytosis makes a significant contribution to clearance of influenza virus infections. J Immunol 2001; 166: 7381-8. [2] Gotoff, R. et al. (1994) Primary influenza A virus infection induces cross-reactive antibodies that enhance uptake of virus into Fc receptor-bearing cells. J Infect Dis, vol. 169(1) p. 200-203. [3] http://www.tulane.edu/~dmsander/WWW/224/Replication.html [4] http://www-micro.msb.le.ac.uk/MBChB/8a.html [5] http://www.medinfo.ufl.edu/year2/mmid/bms5300/bugs/yellowf.html

 

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Documents de l’OMS sur la pneumopathie atypique

Archive 02

Documents de l’OMS sur la pneumopathie atypique

Relevé épidémiologique hebdomadaire 4 AVRIL 2003 http://www.who.int/wer

 

Sommaire

 

Mesures recommandées par l’OMS à l’intention des voyageurs provenant de zones touchées par le syndrome respiratoire aigu sévère (SRAS)

Surveillance mondiale du syndrome respiratoire aigu sévère (SRAS)

SRAS – Fiche de déclaration des cas

Vaccins antipneumogocciques

Règlement sanitaire international

Grippe

 

Mesures recommandées par l’OMS à l’intention des voyageurs provenant de zones touchées par le syndrome respiratoire aigu sévère (SRAS)

Le 15 mars 2003, face aux flambées d’une affection respiratoire déclarées dans plusieurs pays d’Asie, l’OMS a publié des recommandations d’urgence aux voyageurs (http://www.who.int/csr/sarsarchi- ve/2003_03_15/en/). Ces recommandations visaient à prévenir la propagation internationale de la maladie en sensibilisant les professionnels et le public, en renforçant la surveillance et en accélé- rant la prise en charge des cas. Une mise à jour ultérieure en date du 27 mars (http://www.who.int/ csr/sarsarchive/2003_03_27/en/) recommandait d’autres mesures destinées à prévenir la propaga tion internationale moyennant le contrôle des passagers à leur départ des zones affectées. L’article ci-après donne de plus amples détails sur ces recommandations. Le 2 avril, l’OMS a publié de nouvelles recommandations axées sur la sécurité des voyageurs à destination de la Région administrative spéciale de Hong Kong et de la Province de Guangdong en Chine, leur conseillant de différer tout voyage qui ne serait pas absolument indispensable (http://www.who.int/csr/sarsarchive/ 2003_04_02/en/). Chaque pays pourra souhaiter appliquer ces recommandations compte tenu de la politique nationale en vigueur et de ses capacités. Depuis l’introduction de la surveillance mondiale du SRAS à fin février 2003, il apparaît qu’un petit nombre de cas suspects et probables provenant de zones touchées (http://www.who.int/csr/sarareas/2003_03_26/en) ont entrepris des voyages internationaux. Si le nombre de ces cas est restreint, on craint que leur déplacement ne puisse comporter un risque pour les autres voyageurs ainsi qu’un risque de propagation mondiale de la maladie. C’est pourquoi l’OMS recommande aux autorités sanitaires portuaires et aéroportuaires dans les zones touchées de procéder au dépistage chez les personnes souhaitant voyager à l’étranger. De plus, l’OMS émet des recommandations quant à la prise en charge des cas possibles sur les vols internationaux, la désinfection des appareils transportant des cas suspects et la surveillance des personnes ayant été en contact étroit avec des cas suspects et probables au cours d’un voyage international. Bien que ces recommandations concernent avant tout les voyages aériens, la même procédure est préconisée pour les voyages internationaux en provenance des zones touchées par la route, par le rail ou par la voie maritime.

 

Recherche du SRAS chez les cas suspects au départ de zones touchées L’OMS recommande que les gouvernements et les autorités installées aux points d’entrée mettent en place un système leur permettant de collaborer avec les appareils et les autres moyens de transport afin que les personnes quittant une zone touchée pour une destination à l’étranger soient interrogées par un agent de santé au départ et ce, avant l’embarquement. Il s’agira de déterminer si l’intéressé:

· présente ou a présenté au cours des dernières 48 heures un ou plusieurs des symptômes de SRAS (http://www.who.int/csr/sars/casedefinition/en/);

· a eu des contacts avec des cas suspects ou probables de SRAS;

· est fébrile (la température pourra être vérifiée au besoin). Les personnes dont les symptômes correspondent à la définition du cas de SRAS (lien) doivent être orientées vers un service de santé. Quant à celles qui sont uniquement fébriles, on leur recommandera d’attendre la disparition de la fièvre pour partir et de consulter un médecin. Soins destinés aux cas suspects de SRAS en vol

 

Au cas où un passager en provenance d’une zone touchée présente visiblement de la fièvre et des symptômes respiratoires au cours d’un vol, il est recommandé au personnel de cabine de prendre les mesures suivantes:

· isoler dans la mesure du possible le passager concerné des autres passagers et de l’équipage;

· inviter le passager en question à porter un masque protecteur et inviter ceux qui s’occupent de lui à suivre les mesures de lutte contre l’infection recommandées en cas de SRAS;

· réserver un WC à l’usage exclusif du passager concerné;

· faire envoyer par le commandant de bord un message à l’aéroport du lieu de destination pour alerter les autorités de quarantaine ou les autorités sanitaires de l’arrivée d’un cas suspect de SRAS;

· à l’arrivée, isoler le passager malade dont l’état sera évalué par les autorités sanitaires compétentes.

 

Prise en charge des contacts du passager malade

Si l’évaluation médicale immédiate exclut le SRAS, le passager malade devra être orienté vers un de service de santé local pour un suivi éventuel. Si, au contraire, il résulte de cette évaluation médicale initiale à l’aéroport que le passager est bien un cas suspect ou probable de SARS, il conviendra de prendre les mesures ci-après:

 

Contacts

 

1. Toutes les personnes qui sont entrées en contact avec le passager malade doivent être identifiées. Aux fins d’un voyage aérien, un contact est défini comme suit:

· les passagers assis dans la même rangée ou dans les deux rangées devant ou derrière l’intéressé; · tout le personnel de bord;

· toute personne ayant eu un contact intime avec l’intéressé, lui ayant fourni des soins ou ayant été en contact avec ses sécrétions respiratoires;

· toute personne à bord cohabitant avec l’intéressé;

· si un agent de bord est considéré comme un cas suspect ou probable de SRAS, tous les passagers seront considérés comme des contacts.

 

2. Les contacts devront fournir aux autorités sanitaires une pièce d’identité et une justification de leur lieu de résidence pour les 14 jours suivants.

 

3. Les contacts recevront des informations sur le SRAS et seront encouragés à consulter immédiatement un médecin en cas d’apparition de symptômes de SRAS dans les 10 jours suivant le vol. En sollicitant un avis médical, ils devront veiller à ce que toutes les personnes amenées à s’occuper d’eux sachent qu’ils ont été en contact avec un cas suspect de SRAS.

 

4. Les contacts devront être autorisés à poursuivre leur voyage tant qu’ils sont en bonne santé.

 

5. S’il apparaît, par la suite, que le cas suspect est un cas probable de SRAS, l’autorité sanitaire du lieu où le cas est pris en charge devra informer les autorités sanitaires des zones où vivent les contacts qu’une surveillance active de chaque contact (vérification quotidienne de la température et entretien avec un agent de santé) s’impose pendant les 10 jours suivant le vol. Autres passagers A titre de précaution, les passagers et les membres de l’équipage qui ne sont pas considérés comme des contacts devront également fournir aux autorités sanitaires une justification de leur lieu de résidence pour les 14 jours suivant le vol. Ils recevront des informations sur le SRAS et seront encouragés à consulter immédiatement un médecin en cas d’apparition de symptômes de SRAS dans les 10 jours suivant le vol. Ces passagers devront être autorisés à poursuivre leur voyage tant qu’ils sont en bonne santé.

 

Désinfection de l’appareil

Sur la base des premiers éléments concernant l’agent étiologique potentiel du SRAS, il est recommandé de prendre les mesures visées dans le guide OMS de désinfection des aéronefs (http://www.who.int/csr/ihr/guide.pdf). Afin de répondre aux mesures recommandées par l’OMS, les compagnies aériennes devront s’assurer que les vols desservant les zones touchées par le SRAS disposent de suffisamment de gants, de masques protecteurs et de désinfectant, ainsi que d’un siège situé dans un endroit isolé et pouvant être mis à disposition si nécessaire.

 

Surveillance mondiale du syndrome respiratoire aigu sévère (SRAS)

 

Objectif Décrire les données épidémiologiques de SRAS et surveiller l’ampleur et la propagation de cette maladie afin de conseiller les responsables des activités de prévention et de lutte.

Définition des cas (révisée le 1 er avril 2003) Nos connaissances du SRAS évoluent rapidement et il en va de même de l’épidémiologie de cette maladie dans le monde entier; la définition des cas est donc difficile. L’OMS révisera donc la définition des cas de SRAS à mesure qu’elle disposera de nouvelles informations.

La description clinique préliminaire du syndrome respiratoire aigu sévère présente les caractéristiques du tableau clinique connu du SRAS (voir http://www.int/csr/sars/clinical/en/). Les pays pourront être appelés à adapter la définition des cas selon la situation locale. Ils ne sont pas tenus de procéder à une surveillance rétrospective.

 

Cas présumé

 

1. A compter du 1 er novembre 2002 1 , toute personne présentant les signes suivants : poussée fébrile (>38°C) ET toux ou gêne respiratoire ET un ou plusieurs des éléments suivants€au cours des 10 jours précédant l’apparition des symptômes: notion de contact rapproché 2 avec un cas présumé ou probable de SRAS; notion de voyage dans une zone affectée 3 (voir la section Affected Areas (Archives) à l™adresse http://www.who.int/csr/sars/en/); notion de résidence dans une zone affectée 3 (voir la section Affected Areas (Archives) à l™adresse http://www.who.int/csr/sars/en/).

 

2. A compter du 1 er novembre 2002 1 , en l’absence d’autopsie, toute personne atteinte d’une affection respiratoire aiguë inexpliquée ayant entraîné la mort. ET un ou plusieurs des éléments suivants au cours des 10 jours précédant l’apparition des symptômes: notion de contact rapproché 2 avec un cas présumé ou probable de SRAS; notion de voyage dans une zone affectée 3 (voir Affected Areas (Archives) à l™adresse http://www.who.int/csr/sars/en/); notion de résidence dans une zone affectée 3 (voir Affected Areas (Archives) à l’adresse http://www.who.int/csr/sars/en/). Cas probable 1. Cas présumé qui présente à la radiographie thoracique des infiltrations compatibles avec une pneumonie ou un syndrome de détresse respiratoire.

 

2. Cas présumé qui, à l’autopsie, présente des caractéristiques compatibles avec un syndrome de détresse respiratoire sans cause identifiable. 1 La période de surveillance commence le 1 er novembre 2002 pour inclure les cas de pneumonie atypique maintenant reconnus comme des cas de SRAS survenus en Chine. La transmission internationale du SRAS a été signalée pour la première fois en mars 2003 concernant des cas dont les symptômes étaient apparus en février 2003. 2 Contact rapproché: le fait d’avoir donné des soins à un cas présumé ou probable de SRAS, cohabité avec cette personne ou eu des contacts directs avec ses sécrétions respiratoires ou ses liquides biologiques. 3 Zone affectée: zone où les autorités nationales de santé publique déclarent qu’il existe une/des chaîne(s) locale(s) de transmission du SRAS. Critères d’exclusion Le diagnostic sera exclu si un autre diagnostic permet d’expliquer entièrement la maladie. Reclassification des cas Le SRAS étant actuellement un diagnostic différentiel porté par exclusion, la classification d’un cas déclaré peut évoluer. La prise en charge clinique d’un malade doit toujours être appropriée, quelle que soit la classification du cas. Un cas initialement classé comme présumé ou probable dont la maladie peut être entièrement expliquée par un autre diagnostic sera exclu. Un cas présumé qui, après investigations, répond à la définition du cas probable sera reclassé comme « probable ». Un cas présumé ayant un cliché thoracique normal sera soigné de la manière jugée appropriée et placé en observation pendant 7 jours. Une nouvelle radiographie thoracique est nécessaire quand le rétablissement n’est pas satisfaisant. Quand le rétablissement est satisfaisant mais que la maladie ne peut être entièrement expliquée par un autre diagnostic, les cas resteront classés comme « présumés ». En l’absence d’autopsie, un cas présumé qui décède restera classé comme « présumé ». Cependant, si un cas est reconnu comme un maillon de la chaîne de transmission SRAS, le cas sera reclassé comme « probable ». Après autopsie, en l’absence de signes anatomo-pathologiques de syndrome de détresse respiratoire, le cas sera « exclu ». Minimum requis pour la notification 1. Pour les pays n’ayant pas encore déclaré de cas de SRAS Jusqu’à nouvel ordre, les autorités nationales de santé publique doivent informer immédiatement le bureau régional de l’OMS dont elles dépendent par courriel, télécopie ou téléphone de tout cas examiné à la recherche du SRAS (voir l’Annexe 1, Personnes à contacter dans les bureaux de l’OMS). La confidentialité de toutes les informations reçues sera respectée. Les bureaux régionaux de l’OMS, le cas échéant, informeront le Siège de l’OMS à Genève.

2. Pour les pays ayant déjà déclaré des cas de SRAS a) Résumé Jusqu’à nouvel ordre, les autorités nationales de santé publique déclarent à l’OMS, Genève par courriel ou télécopie le nombre total des cas de SRAS par jour (Voir l ‘Annexe 4, Cas de SRAS par pays et par jour). Un exemplaire de ces fiches sera communiqué au bureau régional de l’OMS approprié et au Représentant de l’OMS dans le pays, le cas échéant (voir l’Annexe 1, Personnes à contacter dans les bureaux de l’OMS). L’Annexe 2 décrit schématiquement le mécanisme de déclaration à l’OMS. Avec ces données, l’OMS, Genève dressera chaque jour le bilan de la surveillance mondiale et établira la liste des zones où une/des chaîne(s) locale(s) de transmission du SRAS a/ont été observée(s) (Voir Affected Areas (Archives) à l’adresse http://www.who.int/csr/sarsareas/en/). Seuls les chiffres correspondant à la déclaration des cas probables de SRAS seront publiés. Les cas présumés ou probables seront comptabilisés dans le pays où ils se trouvent actuellement ou dans lequel ils sont décédés. Par exemple, si un malade se rend d’un pays à un autre, le cas sera décompté du total du pays qu’il a quitté. b) Mise en tableau des cas de SRAS Chaque semaine, les autorités nationales de santé publique communiquent à l’OMS, Genève par courriel ou télécopie la liste complète des cas de SRAS. Cette liste doit inclure tous les cas de SRAS apparus à compter du 1 er novembre 2002. Elle doit contenir au minimum les données indiquées à l’Annexe 3, Lexique des données pour la surveillance mondiale du SRAS, où figurent également les codes et le codage des données. Un modèle de tableau sous Excel (SARS_template_line listing.xls) est disponible auprès des Bureaux régionaux de l’OMS. Pendant la maladie, les cas ne sont inscrits qu’une fois dans le tableau et les données relatives à chaque cas sont actualisées si besoin est. Les cas classés comme « exclus » restent enregistrés comme « exclus ». Un exemplaire de ces tableaux doit également être transmis au bureau régional de l™OMS approprié et au Représentant de l’OMS dans le pays, le cas échéant (voir l’Annexe 1, Liste des personnes à contacter à l’OMS). L’Annexe 2 décrit schématiquement le mécanisme de déclaration à l’OMS. Modèle de fiche de déclaration Un exemple du questionnaire concernant chaque cas et pouvant être adapté au pays est présenté à l’Annexe 5 et le fichier électronique est disponible auprès des Bureaux régionaux de l™OMS. Ce questionnaire porte sur les données minimales nécessaires pour définir les cas et comptabiliser les cas par jour et par semaine, et il contient une section qui pourra servir au suivi clinique détaillé.

 

Annexe 1.

 

Personnes à contacter dans les bureaux de l’OMS OMS, Genève

Equipe d’investigation sur la flambée de SRAS Portable: +41 79 500 6542; télécopie: +41 22 791 1397 Mél: outbreak@who.int

 

Bureau régional de l’Afrique D r Paul Lusamba-Dikassa, Conseiller régional, Maladies transmissibles: surveillance et action Tél.: +263 4 746 000/011/070 télécopie: +263 4 746 867/127; Mél: lusambap@whoafr.org Bureau régional des Amériques/OPS D r Marlo Libel, Conseiller régional, Maladies transmissibles: prévention et lutte Tél.: +1 202 974 3129; télécopie: +1 202 974 3259 Mél: libelmar@paho.org Bureau régional de la Méditerranée orientale D r Nadia Teleb, Médecin épidémiologiste Tél.: +202 276 5252; télécopie: +202 276 5414 Mél: telebn@emro.who.int

 

Bureau régional de l’Europe D r Bernardus Ganter, Conseiller régional, Maladies transmissibles Tél.: +45 39 17 13 98; télécopie: +45 3917 18 51 Mél: bga@who.dk Bureau régional de l’Asie du Sud-Est D r M.V.H. Gunaratne, Conseiller régional, Maladies transmissibles: surveillance et action Tél.: +91 11 337 0804; télécopie: +91 11 337 8438 Mél: gunaratnem@whosea.org

 

Bureau régional du Pacifique occidental D r Hitoshi Oshitani, Conseiller régional, Maladies transmissibles: surveillance et action Tél.: +632 528 9730/9964; télécopie: +632 521 1036 Mél: oshitanih@wpro.who.int 106

 

Annexe 5

 

Fiche de déclaration des cas (SRAS)

 

Identifiant unique Caractéristiques de la déclaration

Date de la déclaration (dd/mm/yyyy) Œ (jour/mois/année) / / Pays déclarant Etablissement déclarant Localisation de l’établissement déclarant (par exemple, ville, province) Caractéristiques démographiques Sexe Date de naissance (jour/mois/année) / / Age (en année) Pays de résidence habituelle Nationalité Groupe ethnique Personnel soignant Oui Non Health Si non, profession Signes et symptômes Date d’apparition des premiers symptômes (jour/mois/année) / / Température supérieure à 38 °C Toux Oui / Non / Inconnu Gêne respiratoire Oui / Non / Inconnu Syndrome de détresse respiratoire à l’examen clinique Radiographie thoracique Radiographie thoracique effectuée Oui / No /Inconnu Si oui, signes de pneumonie ou de syndrome de détresse respiratoire Notion d’hospitalisation Le cas a-t-il été hospitalisé alors qu’il était symptomatique? Si oui: Nom de l’établissement hospitalier Ville Date de l’hospitalisation (jour/mois/année) / / Oui / Non / Inconnu Le cas a-t-il été placé en isolement? Si oui: du (jour/mois/année) / / au (jour/mois/année) / / Le cas a-t-il été mis sous ventilation mécanique? Suite de la fiche à impriimer en pdf http://www.who.int/wer/pdf/2003/wer7814.pdf

 

 

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