First detected in Asia in February of 2003, severe acute respiratory syndrome (SARS) has been rapidly identified, decoded and potentially curtailed – at least in Canada and the United States – thus illustrating the power of modern infectious disease measures. At press time, more than 5,000 suspected cases were reported in 26 countries, according to the World Health Organization (WHO), which first named the syndrome.
In the United States, 247 suspected cases of SARS; 41 of these are probable, noted by the director of Centers for Disease Control and Prevention (CDC), during a CDC telebriefing. Of those 41 cases, 39 occurred in travelers to parts of the world where SARS transmission is occurring, one occurred in a healthcare worker and one was a household contact. Twenty-one SARS-related deaths were reported in Canada, although there have been no fatalities from the syndrome in the United States.
They are not seeing spread in the US community at this point in time. Most of the people with SARS in the United States traveled to SARS-affected areas, according to a press briefing by the director of the National Center for Infectious Disease. Symptoms of SARS include a sudden high fever (>100.4 F), a dry cough and difficulty in breathing, and may be associated with headache, muscular stiffness, loss of appetite, malaise, confusion, rash and diarrhea. Symptoms typically manifest from two to seven days after a person is infected.
On April 14, the CDC announced that they had sequenced the genome for the new coronavirus believed to be responsible for the global epidemic of SARS. The CDC sequence is nearly identical to that first determined by researchers at Canada’s Michael Smith Genome Sciences Centre in Vancouver. According to the CDC, the nearly identical findings in the United States and Canada are important because they were derived from different individuals who were infected in different countries. This suggests that the virus probably originated from a common source.
Identifying the genetic sequence of a new virus is important to efforts to treat and prevent it. Research laboratories can use this information to begin to target antiviral drugs, to form the basis for developing vaccines and to develop diagnostic tests that can lead to early detection. The CDC’s analysis of the virus is far from finished, officials noted. Because coronaviruses have the ability to mutate rapidly, scientists will compare the sequences from viruses isolated in cell culture to those obtained from diseases tissue taken from SARS patients. This is essentially a draft. Now we need to see if what we have identified in the laboratory matches what is causing the disease in patients.
CDC urges caution. Meanwhile, CDC officials urge extreme caution when treating patients suspected of having SARS. If there is any suspicion of SARS, the individual should be immediately put into respiratory isolation until additional findings are available. And the pattern of transmission emphasized how important it is, when individuals present with a febrile illness and respiratory syndromes, that a history of travel or history of contact with someone who has recently traveled to high-risk areas be taken.
The WHO and CDC have advised travelers planning elective or nonessential travel to consider postponing all trips to high-risk areas, including mainland China and Hong Kong, Singapore and Hanoi, Vietnam. The transmission may have slowed or stopped in Hanoi. The CDC is not currently recommending that travelers avoid Toronto, which was originally placed on and then removed from the WHO list. Right now, most new cases of SARS are occurring primarily in the healthcare setting in Toronto where SARS patients are being treated.
For individuals who must travel to SARS-affected areas, the CDC advises travelers to wash their hands frequently, and to avoid close contact with large number of people. The CDC does not recommend the routine use of masks. The WHO recommends that anyone with SARS-related symptoms who have traveled to areas with reported cases seek immediate medical attention and inform local healthcare staff.