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The Lessons Learned From SARS
Lessons Learned from SARS
While the focus over the past two years has been on bioterrorism, infectious diseases are an increasing worldwide threat, with or without the help of terrorists. As we learned from Severe Acute Respiratory Syndrome, or SARS, new and inventive viruses and bacteria travel on the backs of innocent victims far and wide, reaching into unsuspecting and often unprepared populations. In 2004 SARS is once again emerging as a headline issue.
In an Institute of Medicine report in March of 2003, titled "Microbial Threats to Health: Emergence, Detection, and Response," the authors warn that we have become too complacent and cite dual risks: first, an increase in animal-borne diseases, and second, bioterrorism.1
The timeline of SARS illustrates that in a world filled with migrating populations, high-speed travel and urban mass crowding, infectious agents predictably spread worldwide at lightening speed. With SARS, a single ill physician from Guangdong Province in China arrived in Hong Kong on February 21, 2003.2 By the next day, 12 guests had become infected and within a week an epidemic was off and running in Hong Kong, Vietnam, Singapore and Canada.
It could have been much worse than it was, were there not vigilant, trained public health professionals on the ground. Dr. James Hughes of the National Center for Infectious Disease at the Centers for Disease Control and Prevention cites one example in an editorial in the Journal of the American Medical Association. "One of the first persons to recognize the potential gravity of the situation was Carlo Urbani, an infectious disease physician working for the [World Health Organization] in Hanoi. Urbani observed that a patient who had recently arrived from Hong Kong had a highly transmissible form of atypical pneumonia, and he promptly alerted WHO officials." He goes on, "Tragically, his heroic actions exposed him to the disease that claimed his life."3
What Carlo Urbani unleashed was a series of highly successful public health strategies, including isolation of suspected cases, contact tracing, quarantine of potentially exposed individuals, use of protective equipment, emphasis on respiratory and hand hygiene, special training for health care workers and enhanced global communications.4
His call engaged the WHO early. On March 12th the organization responded with a Global Alert recommending that patients with atypical pneumonia be isolated and that all suspected cases be reported. By March 14th, in response, Toronto, Canada reported four cases and two deaths.5 And on March 15 th the WHO took the unusual step of issuing a travel advisory for the affected areas, a step not without economic consequences for the areas named, but crucial to gaining an upper hand on the disease.6
Expert teams were rapidly mobilized. A global network of laboratories was organized. And worldwide information sharing though a common data repository was implemented. Within a relatively short period of time, the disease was contained.
Studies now reveal that there is a high likelihood that SARS comes from an animal reservoir in southern China, but the original source of the disease remains unknown.7-8 What we do know, thanks to three collaborating laboratories, is that SARS is a coronavirus, and thanks to two other labs, its genome structure has been entirely mapped. We know where it originated - southern China- but don't know its natural animal host.3
Recurrence of SARS and the emergence of new natural threats is a near certainty. These challenges require scientific leadership, planning and readiness. Clinicians, laboratory specialists, public health experts, epidemiologists and veterinary specialists all need to be on the same page. SARS has now recurred. Future spread may be through reintroduction from an animal reservoir, as an occupational infection of a health care worker or researcher, or as a secondary infection transmitted from a persistently infected primary individual.3
But if it were not SARS, it would certainly be something else. As Dr. Hughes of the CDC counsels, "…newly recognized pathogens will continue to emerge, requiring preparedness, planning, a vigilant health system, a commitment to timely reporting of disease, and strong interdisciplinary partnerships to contain their spread."3
Until next week, for Health Politics, I'm Mike Magee.
References
1.Smolinski MS, ed, Hamburg MA, ed, Lederberg J, ed, for the Committee on Emerging Microbial Threats to Health in the 21st Century, Board on Global Health, Institute of Medicine. Microbial Threats to Health: Emergence, Detection, and Response. Washington, DC: National Academies Press; 2003. Quoted in Hughes JM. The SARS response: Building and assessing an evidence-based approach to future global microbial threats. JAMA. 2003;290:3251-3253.
2.Centers for Disease Control and Prevention. Update: outbreak of severe acute respiratory syndrome-worldwide, 2003. MMWR Morb Mortal Wkly Rep. 2003;52:241-248. Quoted in Hughes.
5.WHO issues global alert about cases of atypical pneumonia [press release]. Geneva, Switzerland: World Health Organization; March 12, 2003. Available at: http://www.who.int/csr/sars/archive/2003_03_12/en/. Quoted in Hughes.
6.World Health Organization issues emergency travel advisory [press release]. Geneva, Switzerland: World Health Organization; March 15, 2003. Available at: http://www.who.int/csr/sars/archive/2003_03_15/en/. Quoted in Hughes.
7.Guan Y, Zheng BJ, He YQ, et al. Isolation and characterization of viruses related to the coronavirus from animals in southern China. Science. 2003;302:276-278. Quoted in Hughes.
8.Martina BE, Haagmans BL, Kuiken T, et al. SARS virus infection of cats and ferrets. Nature. 2003;425:915. Quoted in Hughes.
February 14, 2004
