SARS essons trom a new disease The day-by-day struggle to control the outbreak of severe acute respiratory syndrome(SARS) represents a major victory for public health collaboration. Key lessons emerge that will be invaluable in shaping the future of infectious disease control- and being ready for the da hen the next new disease arrives without warning. First and most important is the need to report, promptly and openly, cases of any disease with the potential for international spread in a closely interconnected and highly mobile world. Second, timely global alerts can prevent imported cases from igniting big outbreaks in new areas. Third, travel recommendations, including screening measures at airports, help to contain the international spread of an emerg- g infection. Fourth, the worlds best scientists, clinicians and public health experts, aided by electronic communications, can collaborate to generate rapidly the scientific basis for con trol measures. Fifth, weaknesses in health systems play a key role in permitting emerging infections to spread. Sixth, an outbreak can be contained even without a curative drug or a vaccine if existing interventions are tailored to the circumstances and backed by political commitment. Finally, risk communication about new and emerging infectio challenge, and it is vital to ensure that the most accurate information is successfully and unambiguously communicated to the public. WHO is applying these lessons across the Organization as it scales up its response to the HIV/AIDS emergency. The first cases On 12 March 2003, WHO alerted the world to the appearance of a severe respiratory illness of undetermined cause that was rapidly spreading among hospital staff in Hong Kong Spe cial Administrative Region( China) and Viet Nam. Within two days, it was clear that the illness was also spreading internationally along major airline routes when hospitals in Singa pore and Toronto, Canada, reported seeing patients with similar signs and symptoms. The potential for further international spread by air travel was vividly illustrated on 15 March. In the early hours of the morning, the head of WHO's outbreak alert and response operations was woken by a call from health authorities in Singapore. A doctor who had treated the first cases of atypical pneumonia there had reported having similar symptoms shortly before board- ing an international flight returning to Singapore from New York. Asked to intervene, WHO alerted the airline and health authorities in Germany, where the flight was scheduled for stopover. The doctor and his wife disembarked in Frankfurt and were immediately hospital ized in isolation, becoming the first two cases in Europe. Because of these events, WHO sued a second, stronger alert later in the day. It set out a case definition, provided advice toSARS: lessons from a new disease 73 5 SARS: lessons from a new disease The day-by-day struggle to control the outbreak of severe acute respiratory syndrome (SARS) represents a major victory for public health collaboration. Key lessons emerge that will be invaluable in shaping the future of infectious disease control – and being ready for the day when the next new disease arrives without warning. First and most important is the need to report, promptly and openly, cases of any disease with the potential for international spread in a closely interconnected and highly mobile world. Second, timely global alerts can prevent imported cases from igniting big outbreaks in new areas. Third, travel recommendations, including screening measures at airports, help to contain the international spread of an emerg￾ing infection. Fourth, the world’s best scientists, clinicians and public health experts, aided by electronic communications, can collaborate to generate rapidly the scientific basis for con￾trol measures. Fifth, weaknesses in health systems play a key role in permitting emerging infections to spread. Sixth, an outbreak can be contained even without a curative drug or a vaccine if existing interventions are tailored to the circumstances and backed by political commitment. Finally, risk communication about new and emerging infections is a great challenge, and it is vital to ensure that the most accurate information is successfully and unambiguously communicated to the public. WHO is applying these lessons across the Organization as it scales up its response to the HIV/AIDS emergency. The first cases On 12 March 2003, WHO alerted the world to the appearance of a severe respiratory illness of undetermined cause that was rapidly spreading among hospital staff in Hong Kong Spe￾cial Administrative Region (China) and Viet Nam. Within two days, it was clear that the illness was also spreading internationally along major airline routes when hospitals in Singa￾pore and Toronto, Canada, reported seeing patients with similar signs and symptoms. The potential for further international spread by air travel was vividly illustrated on 15 March. In the early hours of the morning, the head of WHO’s outbreak alert and response operations was woken by a call from health authorities in Singapore. A doctor who had treated the first cases of atypical pneumonia there had reported having similar symptoms shortly before board￾ing an international flight returning to Singapore from New York. Asked to intervene, WHO alerted the airline and health authorities in Germany, where the flight was scheduled for a stopover. The doctor and his wife disembarked in Frankfurt and were immediately hospital￾ized in isolation, becoming the first two cases in Europe. Because of these events, WHO is￾sued a second, stronger alert later in the day. It set out a case definition, provided advice to