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Current SARS Situation Currently, there is no known SARS transmission anywhere in the world. The most recent human cases of SARS-CoV infection were reported in China in April 2004 in an outbreak resulting from laboratory-acquired infections (see Laboratory Biosafety for more details). CDC and its partners, including the World Health Organization, continue to monitor the SARS situation globally. Any new updates on disease transmission and SARS preparedness activities will be posted at this site SARS OutbreakInformation for International Travelers -- Eliot C. Heher, MD and Members of the HTH Worldwide Physician Community |
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June 03, 2003
Update as of June 23, 2005 -- click here |
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Background Cause Investigators suspect that SARS is caused by a new type of Coronavirus. Thanks to remarkable international cooperation among scientists, the suspect virus has been identified and its DNA sequenced. Additional research is necessary, however, to confirm these findings. Coronaviruses are very well known as the cause of colds and other (generally mild) respiratory infections in humans, but not as a cause of pneumonia. In animals, coronaviruses cause a large number of illnesses. Traditional antibiotics are not effective against viruses. Anti-viral medications are, in general, less effective than physicians would like, and the front-line response to one anti-viral drug tried in Hong Kong has been limited (see below-Treatment). Health officials are particularly concerned that the disease is caused by a new virus because: (1) it means very few if anyone will have antibodies to the disease, so it can spread quickly through the population; (2) it means that available treatments may not be effective; (3) it means that available vaccinations will not be effective. Spread Most of the victims have had close contact with at least one other victim (that is, they helped care for other victims either at home or in a hospital), or they have traveled recently to affected areas such as Hong Kong. The WHO recently studied 35 airplane flights on which a probable SARS- infected individual was aboard; the results indicate that spread to other passengers or crew occurred on only 4 of these 35 flights. Officials believe the disease is spread primarily from infected droplets and secretions, but not through the air. It does appear that the virus can survive for up to 48 hours after drying on plastic surfaces and in feces, and for 24 hours in urine. "Superspreaders" appear to be important in the spread of SARS. Superspreaders are infected individuals who, for unclear reasons, are able to infect a large number of other people. They may or may not be symptomatic at the time they are contagious. Some of these Superspreaders have been responsible for as many as 50 other cases. Symptoms, Diagnosis, and Outcome Symptoms begin approximately two to seven days after exposure to the disease, though the incubation period can be as long as ten days. Generally the illness follows two to three phases:
The death rate from SARS is higher than initially believed, and varies with age. The WHO estimates a rate of less than 1% in persons aged 24 years or younger, 6% in persons aged 25 to 44 years, 15% in persons aged 45 to 64 years, and greater than 50% in persons aged 65 years and older. Because a large number of victims remain hospitalized, and their ultimate outcome unknown, a more precise estimate of the death rate is impossible at this time. Prevention The best way to avoid the illness is to avoid affected areas of the world and avoid affected individuals, if possible. HTH Participating Physicians in China and Thailand are advising local expats to avoid crowded places (including cinemas and shopping areas), to fly only if it is really necessary, to keep their hands away from their mouth and nose, and to pay particular attention to hand washing-even to the extent of carrying a small bottle of rubbing alcohol in the pocket for use after contact with possibly infected surfaces such as handrails, door handles, elevator buttons, etc. Many individuals in Hong Kong and elsewhere wore respiratory masks during the peak of the outbreak. Generally the best masks are special N95 "respirators" that are more effective at blocking viruses than gauze and surgical masks. HTH Participating Physicians in China report that the masks significantly reduce the risk of infection, and recommend their use for anyone using public transportation or visiting a crowded or poorly ventilated place such as an elevator. The CDC has recommended the use of masks for healthcare workers in hospitals, clinics, and emergency departments. Travel Restrictions As of June 3, 2003, the WHO recommends that travelers consider postponing elective travel to Taiwan and certain other areas of China (Beijing, Hebei, Inner Mongolia, Shanxi, Tianjin). The WHO bases this list on places that have ongoing local spread of the disease (as opposed to spread resulting from individuals who arrive from affected areas). The WHO has not reinstated travel restrictions for Toronto, despite the recent reemergence of the disease there. Travelers and expatriates currently abroad should be aware that they may not be allowed to leave a country if they become sick with SARS, regardless of their nationality or permanent residence. In addition to legal restrictions imposed by the departure and the destination country on SARS-affected individuals, there are few if any medical ambulance companies willing to perform evacuations of SARS patients. WHO guidelines require that an airplane used for such a mission have an entirely separate air circulation system for passengers and crew-but no such airplane exists. Evacuations, when performed, have cost hundreds of thousands of dollars (many times what a typical evacuation costs). Treatment Victims who are hospitalized with mild cases receive intravenous fluids, nursing care and possibly medications for standard community acquired pneumonia, as secondary infections with bacteria can occur. Patients are treated in negative-pressure isolation rooms - that is, a room whose air pressure is kept below the outside air pressure to prevent spread of the infectious agent. In Hong Kong and in Canada the more seriously ill have been treated with an anti-viral drug called ribavirin as well as high doses of glucocorticoid-type steroids, the latter to limit the damage to the lungs from inflammation. However, there has been no widespread acceptance of this regimen, which commonly causes side effects. Leading AIDS researchers, expert virologists, biotechnology companies and large pharmaceutical companies have all joined the hunt for effective agents, but the search is likely to require years of effort. HTH Participating Physicians in Asia report that individuals who receive treatment early in the course of their disease do better than those who remain in the community for many days with high fever. Recommendations
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Healthy Travel
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| SARS Outbreak -- from HTH Worldwide |