There is no sign of the SARS epidemic abating, quite the contrary it seems to be deriorating. Looking at today's figures - 3,000 cases and 117 deaths - the death rate seems somewhere just under 4%. A week ago the numbers were about 2,300 and 78 dead. That seems to be around a 30% increase per week, which is big, very big. On the good news front a team of investigators have established that it is a corona virus with a common point of origin. The bad news, this means that it can either be spread by direct contact. or by large droplets of body fluid deposited on surfaces. Hence the need to disinfect airplanes. Then there is the possibility of super-carriers. The cases in Singapore all seem to originate with one carrier who is immune. Also note the case of the marathon traveller who was in fact suffering from the disease. Like many people I'm reading Duncan Watts 'Six Degrees', and I'm convinced that major problems don't originate from catastrophes, but from a series of small but important incidents. Finally the proposed name for the virus: the Urbani SARS-associated coronavirus.
There is no sign of the global SARS outbreak abating, with a worrying surge in new cases in Hong Kong on Friday, and a senior Chinese health official warning that the outbreak is not under control. Epidemiologist Zhong Nanshan, director of the Respiratory Disease Research Institute in the Guandong province where SARS originated, disputed the Chinese government's claims to have controlled SARS. "Looking at this from a medical point of view, this disease has not been effectively controlled at all," he said. "The origin of this disease is still not clear, so how can you say it has been controlled?" He said "contained" might be a better description. Following initial work, the World Health Organization is to strengthen its investigative team in China. "This is necessary for us to have a better understanding of the disease and develop more effective control and treatment strategies for SARS," says Hitoshi Oshitani, a WHO regional adviser in Manilla, the Philippines. By Friday, Severe Acute Respiratory Syndrome (SARS) had killed at least 117 people and infected over 3000 in over 30 countries. The key problem hampering the efforts of health officials to halt the outbreak is their continued lack of understanding about how the virus that causes the disease spreads. As a result, draconian protective measures are being implemented in many countries around the world, with thousands being held in quarantine. On Friday, the Hong Kong authorities also barred people who have had close contact with SARS victims from leaving the region. Police have hunted down a number of people who fled quarantine. In Singapore, the authorities aim to ensure compliance by installing internet-linked cameras in the homes of quarantined people. And in Canada, blood donations from people who have visited SARS-affected regions have been stopped, as a precaution.Most SARS victims are either closely related to other victims or healthcare personnel working with patients. The virus probably spreads via direct inhalation of the body fluids expelled by coughing, or by touching surfaces soon after they are infected. But investigators are still examining how some unrelated people have contracted SARS. "Super-spreaders", who survive the disease but are highly infectious, are one possibility. A young Singaporean woman is now believed to be linked to virtually all of that country's 130 cases. New information has also emerged from the investigation of the Amoy Gardens housing complex in Hong Kong, where 200 resident caught SARS. The virus was found in basins and toilets, say officials, suggesting the virus travelled through the clogged sewage system. Malik Pieris, head of virology at the University of Hong Kong, also reports that tests show the virus can survive in faeces.
Source: New Scientist
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New England Journal of Medicine: ABSTRACT
Background A worldwide outbreak of severe acute respiratory syndrome (SARS) has been associated with exposures originating from a single ill health care worker from Guangdong Province, China. We conducted studies to identify the etiologic agent of this outbreak.
Methods We received clinical specimens from patients in six countries and tested them, using virus isolation techniques, electron-microscopical and histologic studies, and molecular and serologic assays, in an attempt to identify a wide range of potential pathogens.
Results No classic respiratory or bacterial respiratory pathogen was consistently identified. However, a novel coronavirus was isolated from patients who met the case definition of SARS. Cytopathological features were noted microscopically in Vero E6 cells inoculated with a throat-swab specimen. Electron-microscopical examination of cultures revealed ultrastructural features characteristic of coronaviruses. Immunohistochemical and immunofluorescence staining revealed reactivity with group I coronavirus polyclonal antibodies. Consensus coronavirus primers designed to amplify a fragment of the polymerase gene by reverse transcription-polymerase chain reaction (RT-PCR) were used to obtain a sequence that clearly identified the isolate as a unique coronavirus only distantly related to previously sequenced coronaviruses. With specific diagnostic RT-PCR primers we identified several identical nucleotide sequences in 12 patients from several locations, a finding consistent with a point source outbreak. Indirect fluorescent antibody tests and enzyme-linked immunosorbent assays made with the new coronavirus isolate have been used to demonstrate a virus-specific serologic response. Preliminary studies suggest that this virus may never before have infected the U.S. population.
ConclusionsA novel coronavirus is associated with this outbreak, and the evidence indicates that this virus has an etiologic role in SARS. The name Urbani SARS-associated coronavirus is proposed for the virus.
Source: New England Journal of Medicine
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An international airline is contacting some of its recent passengers after a man who made seven flights in less than a week was diagnosed on Thursday with the deadly Sars virus. The man's journey took him from Asia to several European capitals and back to Asia again. Lufthansa - the airline he used for all seven flights - has been trying to contact passengers and employees who had direct contact with him. One UK man who had contact with him has been taken into hospital with a probable case of Sars. The World Health Organisation has said the risk of air passengers spreading the disease mid-flight is extremely low. But the incident highlights the problems facing health officials attempting to halt the worldwide spread of the virus. The infected man, who has not been named, started and ended his journey in Hong Kong. The territory has so far recorded nearly 1,000 cases of the Sars virus and ranks as the most severely affected region after mainland China. According to the Department of Health in Hong Kong, the 48-year-old victim flew to Munich on 30 March, before travelling on to Barcelona, where he first developed symptoms of the virus. On 2 April he took another flight to Frankfurt, before moving on to London, back to Munich, back to Frankfurt and then finally returning to Hong Kong on 5 April. He was then admitted to a hospital in Hong Kong and diagnosed with Sars on Thursday, the Department of Health said. Lufthansa said it had disinfected all the planes involved and was confident that the chances of any passengers becoming infected were "very remote".
Source: BBC
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