Cumulative Number of Reported Probable Cases. From: 1 Nov To: 12 June 2003, 17:00 GMT+2

Transcription

1 Cumulative Number of Reported Probable Cases From: 1 Nov To: 12 June 2003, 17:00 GMT APBN Vol. 7 No

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3 Notes: Cumulative number of cases includes number of deaths. As SARS is a diagnosis of exclusion, the status of a reported case may change over time. This means that previously reported cases may be discarded after further investigation and follow-up. 1. The start of the period of surveillance has been changed to 1 November 2002 to capture cases of atypical pneumonia in China that are now recognized as being cases of SARS. 2. A decrease in the number of cumulative cases and discrepancies in the difference between cumulative number of cases of the last and the current WHO update are attributed to the discarding of cases. 3. Includes cases who are discharged or recovered as reported by the national public health authorities. 4. One death attributed to Hong Kong Special Administrative Region of China occurred in a case medically transferred from Viet Nam. 5. These two new probable cases, with onsets of illness 25 and 27 February 2003, were identified retrospectively in the United Kingdom. They both most likely acquired their infection in Hong Kong SAR and became ill and recovered while in the Philippines. 734 APBN Vol. 7 No

4 Update 80 Change in Travel Recommendations for Parts of China, Situation in Toronto 13 June 2003 Change in Travel Recommendations Effective today, the World Health Organization (WHO) is removing its recommendation that people should postpone all but essential travel to Hebei, Inner Mongolia, Shanxi and Tianjin regions in China. Recommendations to consider postponing all but essential travel to these regions of China were issued on 23 April and 8 May in order to minimize the international spread of Severe Acute Respiratory Syndrome (SARS). WHO is changing this recommendation as the situation in these areas has now improved significantly. Information about the decline of the outbreaks in Hebei, Inner Mongolia, Shanxi and Tianjin has been carefully reviewed by WHO and suggests that SARS is no longer a potential threat to international travellers to these regions. Recommendations to postpone travel are issued following consideration of several factors, including the magnitude of current SARS cases, the pattern of recent local transmission, and the last dates of export of cases. In addition, WHO is removing Guangdong, Hebei, Hubei, Inner Mongolia, Jilin, Jiangsu, Shaanxi, Shanxi and Tianjin from the list of areas with recent local transmission. This follows confirmation that there have been no new cases isolated in any of these areas for more than twice the maximum incubation period, in other words more than 20 days. On 27 March, WHO recommended that areas with recent local transmission should screen all international departing passengers to ensure that those who are sick with SARS or are contacts of SARS cases do not travel. This recommendation is still valid for Beijing, Hong Kong and Taiwan in China, and Toronto, Canada. During a recent trip to Beijing, Dr. David Heymann, WHO s Executive Director for Communicable Diseases, commented on the measures now in place in China to contain the spread of SARS. We ve seen that there has been a massive effort to mobilize the population both in urban and rural areas across the country, encouraging people to monitor themselves for fever and to ensure that SARS cases are quickly identified, isolated and treated. China has made huge strides in its effort to contain the outbreak of SARS, said Dr. Heymann. The key thing now is to maintain vigilance and build up China s disease surveillance system. Public health authorities in China and around the world must continue to watch out for new cases of SARS to ensure that it does not emerge again elsewhere. APBN Vol. 7 No

5 Situation in Toronto The category of pattern of SARS transmission for the city of Toronto has been changed from B to C. This is because a probable case with laboratory confirmation of SARS coronavirus exported from Toronto had not been previously identified as a contact and put into voluntary home isolation. Pattern B transmission is defined as an area having more than one generation of local probable SARS cases, but only among persons who have been previously identified and followed-up as known contacts of probable SARS cases. Pattern C transmission is defined as an area having local probable cases occurring among persons who have not been previously identified as known contacts of probable SARS cases. Update 79 Situation in China 12 June 2003 China s Executive Vice Minister of Health, Mr. Gao Qiang, and Dr. David Heymann, WHO s Executive Director for Communicable Diseases, briefed the press this morning on the situation of SARS control in China. Also in attendance were Dr. Qi Ziaoqiu, Director-General of the Department of Disease Control in the Chinese Ministry of Health, and Dr. Henk Bekedam, WHO Representative to China. The briefing marked the first joint news conference between high-ranking Chinese and WHO officials since the SARS outbreak began. The briefing followed a day of intensive meetings during which WHO officials reviewed data and statistics from selected provinces, voiced their concerns, and received frank and detailed answers. Dr. Heymann praised the openness with which the WHO team was welcomed by the Ministry of Health, and described the measures now in place to control and prevent SARS as excellent. He cited the high level of commitment and determination at all levels of the health system as largely responsible for the dramatic recent decline in the number of cases seen throughout Mainland China. One purpose of the visit was to determine how China had succeeded in bringing down the number of cases so rapidly, and to encourage officials to share their experiences with the rest of the world. Indications of the effectiveness of control measures, cited by Dr. Heymann, include the very short time now occurring between the onset of symptoms and the detection and isolation of cases, and the speed and efficiency of contact tracing. Such measures are important as they limit the amount of time that an infected person is capable of spreading the virus to others and thus bring control efforts closer to the stage when the chain of person-to-person transmission can be broken. Other effective measures include systems for both passive and active surveillance, such as fever checks at train and bus stations and airports, a nationwide mass media campaign to inform and educate the public, and a very large number of fever clinics to assess those who suspect they may have symptoms. We ve seen that there has been a massive effort to mobilize the population both in urban and rural areas across the country, encouraging people to monitor themselves for fever and to ensure that SARS cases are quickly identified, isolated and treated. 736 APBN Vol. 7 No

6 Specific concerns expressed by the WHO team include the lack of a sustainable surveillance system that can be relied on to detect the first hints of a resurgence of cases, some delays in meeting WHO requests for further information, and wide variations in application of the national case definitions, which can lead to under-reporting of cases. Some problems related to prompt sharing and analysis of data are considered to arise from institutional and administrative problems, particularly concerning the information flow from provinces to the central level. Another major concern is the large number of cases that have no known source of exposure, thus making it extremely difficult to trace patterns of transmission. In Beijing, the number of cases with no known contact with a SARS patient has recently increased from 50 percent to more than 70 percent. In the interest of protecting against a further resurgence of cases, WHO officials singled out strengthening of surveillance capacity as the top priority. Experience to date has shown that a single case, especially if highly infectious, can rapidly ignite an explosive outbreak. With SARS seemingly on the decline for now, there is a great need to strengthen the SARS control and surveillance system in China, said Dr. Bekedam. The system now in place grew out of an emergency response and has to be strengthened for the long run. He expressed doubt that the present system would be strong enough to hold back the tide when confronted with a resurgence of the disease. In his assessment of the long-term SARS situation in China, Dr. Heymann also stressed the need for systematic studies of the origins of SARS. We still don t know exactly where SARS came from, or how it was transferred to the human population. We don t know if this disease is seasonal and will decrease this year but come back next year. Until proper research into the origins of SARS has been conducted, it will be impossible to predict when the conditions that first allowed the virus to jump to humans from a suspected animal reservoir might be repeated in the near or distant future. WHO initial assessments of the SARS situation in China, issued in late April following a visit to Guangdong Province, expressed serious concern over the lack of urgency in reporting cases of SARS in China, and criticized the government for not immediately treating the outbreak as a public health emergency requiring extraordinary measures for its control. Dr. Heymann and other members of the WHO team are now satisfied that these measures are in place, at least for the immediate response to SARS. Recent visits to selected provinces, jointly conducted by the Chinese Ministry of Health and WHO, found a high level of public awareness of SARS, its symptoms and mode of transmission, and the need for twice-daily fever checks. China is regarded as the epicenter of the SARS outbreak. The country was home to the first cases, detected in mid-november of last year, and presently accounts for almost two thirds of all reported cases worldwide. The WHO visit was arranged to secure reassurance that control measures in this vast country are adequate to continue the downward trends in cases and, equally important, to ensure that a sustainable system is in place to detect and contain a resurgence of cases. WHO is also anxious to ensure that the considerable knowledge and experience acquired in managing the largest SARS outbreak on record is shared for the benefit of all countries. The SARS outbreak has revealed substantial weaknesses in the disease surveillance system in China. When investment in health infrastructure is neglected, conditions are ripe for the unchecked spread of any epidemic-prone disease, often at tremendous cost to a nation s economy. In the view of WHO, the surveillance system in China needs to be made more flexible and capable of a much more rapid and consistent response to any new infectious disease threat. During the visit, Chinese officials expressed deep concern about the country s capacity to deal with the next influenza season against a background of possible SARS cases. The presence of influenza could greatly complicate the detection and accurate diagnosis of SARS cases, while also increasing the caseload of suspect cases considerably. APBN Vol. 7 No

7 The containment of SARS remains the overriding objective of WHO. If SARS is not contained, the world will face a situation in which every case of atypical pneumonia, and every hospital-based cluster of febrile patients with respiratory systems will have the potential to rouse suspicions of SARS and spark widespread panic. In an earlier report, a WHO assessment team reached the following conclusion: If SARS is not brought under control in China, there will be no chance of controlling the global threat of SARS. Achieving control of SARS is a major challenge especially in a country as large and diverse as China. Effective disease control and reporting are the cornerstone of any strategy to do this. WHO Officials to visit China 10 June 2003 Dr. David Heymann, Executive Director for Communicable Diseases at WHO, is travelling today to China, where he will confer with health officials about the SARS outbreak and discuss plans for the future. Other members of the team include Dr. Guénaël Rodier, Director of Communicable Disease Surveillance and Response, and Dr. Thomas Grein, who coordinates global response operations for SARS. The purpose of the visit is to take stock of the current SARS situation in China and exchange views on the next steps forward. In particular, WHO would like to develop, in collaboration with the Chinese government, a research agenda that fully exploits the many intriguing lines of evidence uniquely associated with the SARS experience in China. WHO officials also want to assess areas where Chinese authorities may require more support to ensure that the disease is securely contained and to protect against a future recrudescence of cases. SARS is a serious disease with many puzzling features, said Dr. Heymann. Long-term containment depends on finding answers to a long list of scientific questions. China has much to offer the rest of the world. Some immediate issues for discussion concern case definitions, procedures for contact tracing, and the extent of local transmission in specific areas. The WHO team further seeks reassurance that hospital equipment and supplies for infection control are adequate, especially in the poorer provinces. Measures may need to be found for sustaining China s present monumental effort to contain SARS, particularly as programs for responding to other priority diseases, such as HIV/AIDS and TB, may suffer in the long run. Weaknesses in the health infrastructure, notably inadequate surveillance, reporting, and hospital facilities in some of China s poorer provinces, have been of concern since the first report of a WHO assessment team was issued in early April. Both WHO and the Chinese Ministry of Health regard the emergency response to SARS as an excellent opportunity to strengthen, throughout the mainland, systems for detecting and responding to all emerging and epidemic-prone infectious diseases. Such long-term and comprehensive improvements will also strengthen China s capacity to respond to the next influenza pandemic, which many experts now regard as imminent. WHO officials are also hoping to learn which measures taken by China have so rapidly brought the country s SARS outbreak the largest in the world under control. 738 APBN Vol. 7 No

8 The first cases of SARS were detected in Guangdong Province, China, in mid-november of last year. That outbreak has since been brought under control. Initial studies suggest a lower case fatality ratio than seen elsewhere, and high cure rates. In addition, a report on the epidemiology of the outbreak, issued in mid-may by the Chinese Center for Disease Control and Prevention, provides evidence suggesting that close contact with wild game animals is linked to the first sporadic cases, supporting a hypothesis that the SARS virus may have jumped to humans from an animal reservoir. In addition, the outbreak in Guangdong Province shows some features, in terms of incubation period and groups at highest risk, that differ from the clinical picture seen in outbreaks elsewhere. Answers to these and other questions will help build a solid scientific basis for understanding SARS, predicting its future evolution, and knowing how to respond should cases surface in new areas or resurface in areas where the disease has been contained. Unlike many new diseases that have emerged in the past two decades, SARS shows no sign of burning out on its own. If the disease is pushed back out of its new human host, this will result from the persistent application of simple yet highly effective control tools prompt detection and isolation of cases, strict infection control in hospitals, and tracing and appropriate follow-up of all contacts. Both Viet Nam and Singapore have successfully broken the chain of transmission and have since remained free of SARS. However, the risk of importation of cases remains as long as cases are occurring anywhere in the world. The visit to China is one in a series in which WHO officials, including the current Director-General, Dr. Go Harlem Brundtland, and the Director-General elect, Dr. J.W. Lee, confer with health authorities at SARS outbreak sites having the greatest experience to date. Dr. Brundtland will be visiting Hong Kong SAR later this month. Global Decline in Cases and Deaths Continues 5 June 2003 As of today, a cumulative total of 8403 probable cases with 775 deaths has been reported from 29 countries. This represents an increase of 6 new cases and 3 deaths compared with yesterday. The new cases occurred in Canada (5) and Taiwan (1). New deaths were reported in China (2) and Hong Kong (1). Health authorities in some of the earliest areas to experience severe outbreaks are maintaining measures to protect against a resurgence of cases. Hong Kong authorities have announced their intention to maintain current screening procedures at all border points for at least one year. The measures, which began at the end of March, include use of infrared temperature scanners at border points, and obligatory health declarations from all travelers. No new imported cases have occurred since these measures were introduced. Hong Kong is also setting up a master list of imported cases. Approximately 6 percent of all SARS cases in Hong Kong are now thought to have been imported. To date, Hong Kong has experienced 1748 cases and 284 deaths, making it the second more severely hit area, with mainland China at the APBN Vol. 7 No

9 top. Hong Kong shares a border with Guangdong Province, China. The disease was first brought to Hong Kong in late February when an infected medical doctor from the province spread the virus to at least 13 guests and visitors, all on the same floor of the hotel where he stayed. They carried the disease with them when they returned home, seeding the earliest outbreaks in Viet Nam, Singapore, and Toronto as well as Hong Kong. In these initial outbreaks, SARS first took root in hospital settings, where staff, unaware that a new disease had surfaced and fighting to save the lives of patients, exposed themselves to the infectious agent without barrier protection. All of these initial outbreaks were subsequently characterized by chains of secondary transmission outside the health care setting. At present, local chains of transmission are occurring only in Toronto and several parts of China. All other countries with imported cases have managed either to prevent transmission entirely or limit additional cases to very small numbers. Status of Diagnostic test, Training course in China 2 June 2003 Status of Diagnostic Tests The development of commercial diagnostic tests for SARS has progressed more slowly than initially hoped. Part of the problem arises from certain unusual features of SARS that make this disease an especially difficult scientific challenge. For many viral diseases, the greatest quantities of the causative agent are excreted during the initial phase of illness, usually in the first few days following the onset of symptoms. This is often the period during which patients pose the greatest risk of infecting others. SARS, however, follows a different pattern. During the initial phase of illness, virus shedding is comparatively low. Virus shedding peaks in respiratory specimens and in stools at around 10 days after onset of clinical illness. In effect, this unusual behavior creates the need for tests having a particularly high sensitivity. Such tests do not yet exist. Because small quantities of the virus are initially shed, available tests, though developed with impressive speed, are unable reliably to detect SARS virus or its genetic material, during the earliest days of illness. The low sensitivity of current virus detection tests is a particular challenge for SARS control, as patients are capable of infecting others during the initial phase and therefore need to be reliably detected and quickly isolated. In SARS patients, detectable immune responses do not begin until day 5 or 6. Reliable antibody tests can detect virus only by around day 10 following the onset of symptoms. WHO continues to recommend use of its case definitions, based on clinical presentation, distinct chest X-rays, and history of possible contact with SARS patients, to detect suspect and probable cases and make management decisions. 740 APBN Vol. 7 No

10 To expedite the development of better diagnostic tests, laboratories in the WHO collaborating network have made critical biological materials and reagents available to any laboratory having a sustained interest in the development of diagnostic tests, including the commercial sector. A comprehensive bank of clinical specimens, including respiratory specimens and samples of blood, urine, and feces from SARS patients, has been established. The bank holds specimens representing all stages of the disease, ranging from the onset of symptoms to recovery. During the development of diagnostic tests, such specimens are needed to assess how well a test will perform with real patients specimens, as opposed to under the artificial conditions of a laboratory. Specimens from the bank, which was set up by the Hong Kong Department of Health and the Hospital Authority, are being supplied by a collaborating laboratory, at no charge, to developers of diagnostic tests. As a sample from a single specimen can be subdivided into 6 to 8 identical sub-samples, laboratories can work in parallel on identical specimens, which will further facilitate the assessment of comparative performance. Identical samples also support standardization of diagnostic tests to ensure consistent accuracy. Laboratories in the WHO network have also made available standardizing reagents for virus and antibody tests. These reagents, which include samples of the inactivated virus and blood from patients in both acute and convalescent stages of illness, will allow uniform assessment of diagnostic results around the world against a gold standard. Sera have been made available by collaborating laboratories in the United Kingdom and Hong Kong. Inactivated virus was prepared by the Bernard-Nocht Institute in Germany. Distribution of these reagents will be the responsibility of the Robert-Koch Institute, also in Germany. In return for the supply of these exclusive materials, recipients of WHO support have agreed to offer test kits, once available, at preferential prices to developing countries. Training Course in China WHO is currently coordinating a series of training courses in Beijing aimed at establishing an efficient laboratory infrastructure for SARS diagnosis in all provinces throughout China. Work of the WHO laboratory network has made it possible to support the training courses with test materials and reagents. Training in the use of currently available tests is being provided by representatives of the labs where they were developed thus ensuring that Chinese professionals benefit from the best first-hand experience the world can offer. Trainers come from laboratories in China, Hong Kong, the UK and the USA. China has already developed a highly promising ELISA diagnostic test. For early detection of SARS virus, the PCR molecular test offers the greatest potential under average hospital conditions. The Singapore Genomic Institute has made its PCR test available, at no cost, to support SARS diagnosis in China. Although the number of new cases and deaths has declined considerably in mainland China, WHO and Chinese authorities remain concerned about the situation in some of the remote provinces which lack a sufficiently strong health infrastructure, including surveillance and reporting systems and hospital facilities, for responding to the magnitude of the SARS problem. APBN Vol. 7 No

11 SARS Travel Recommendations Summary Table 13 June 2003 This table, updated daily, indicates those areas with recent local transmission of SARS for which WHO has issued recommendations pertaining to international travel. All international travelers should be aware of the main features of SARS and the areas of the world where local transmission has been reported. This table summarizes those areas of the world for which further specific measures have been recommended. 742 APBN Vol. 7 No