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Figure 3. Canada, number of cases

Singapore, February 2003

The index case of SARS in Singapore was a previously healthy 23- year-old woman of Chinese ethnicity who had been staying on the 9th

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floor of Hotel M during a vacation to Hong Kong from February 20– 25, 2003 (Hsu). She developed fever and a headache on February 25 and a dry cough on February 28. She was admitted to a hospital in Singapore on March 1. At that time, SARS had not yet been recognized as a new disease easily spread in hospitals. As a result, hospital staff were unaware of the need to isolate patients and protect themselves. Over a period of several days, the index patient infected at least 20 other people. No further transmission from this patient was observed after strict infection control measures were implemented (Hsu).

Figure 4. Epidemic curve, Singapore (from Yeoh).

The virus initially spread rapidly among hospital staff, patients, visitors, and their close family contacts. Later on, spread of infection between hospitals occurred when patients with underlying disease – which masked the symptoms of SARS – were transferred to other hospitals, placed in rooms with other patients, and managed without adequate protective equipment (WHO Update 70).

The outbreak in Singapore was amplified by several so-called "superspreaders" (see also chapter 3: Transmission). 144 of Singapore's 206 probable cases have been linked to contact with only 5 individuals (WHO Update 70; Figure 5).

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Figure 5. Probable cases of severe acute respiratory syndrome, by reported source of infection — Singapore, February 25–April 30, 2003 (from MMWR 52: 405-11)

On April 20, after the identification of a cluster of illness among employees at a crowded wholesale market, the market was closed for 15 days and more than 400 persons were placed in home quarantine. The spread of infection was limited to only 15 other persons.

In Singapore, 76% of infections were acquired in a healthcare facility; the remainder either had household, multiple, or unknown exposures. Due to rigorous contact tracing and isolation procedures, 81% of probable SARS cases had no evidence of transmission to other persons with a clinically identifiable illness (MMWR 2003; 52: 405-11).

Of the 84 (42%) healthcare workers with probable SARS, 49 were nurses; 13, physicians; and 22, persons with other occupations (attendants, radiographers, housekeepers, a porter, and a cleaning supervisor); no SARS cases have been reported among laboratory workers or pathologists (MMWR 2003; 52: 405-11).

238 cases of SARS were diagnosed in Singapore; 33 patients died.

On May 31, Singapore was removed from the list of areas with recent local transmission (WHO Update 70).

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China

Up until mid-April, the Chinese authorities underestimated the magnitude of the epidemic in Beijing, with only 37 cases having been reported by April 19. In the following two days, the Chinese authorities announced more than 400 (WHO Update 35) new SARS cases. Additional reports (WHO Update 36) indicated that SARS had spread to other provinces, including western Guangxi, northern Gansu, and Inner Mongolia.

On April 23, the WHO extended its SARS-related travel advice (WHO Update 37) to Beijing and the Shanxi Province of China, recommending that persons planning to travel to these destinations consider postponing all but essential travel. Four days later, the Chinese Authorities closed theaters, Internet cafes, discos and other recreational activities and suspended the approval of marriages in an effort to prevent gatherings where SARS could be spread.

To date, the epidemic in China seems to be under control. 5,327 cases of SARS have been diagnosed, 349 patients have died.

On June 24, Beijing was removed from the list of areas with recent local transmission (WHO Update 87).

Taiwan

The first two suspected SARS cases were diagnosed in a couple on March 14. The man had a history of travel in February to the Guangdong Province and to Hong Kong. On March 26, a Taiwanese resident of Hong Kong's Amoy Gardens flew to Taiwan and took a train to Taichung to celebrate the traditional festival, Qing Ming. The man’s brother became Taiwan’s first SARS fatality, and a fellow passenger on the train was also infected.

Suddenly, in the last 10 days of April, the number of cases began to increase steadily, which would have made Taiwan's epidemic the third-worst in the world after China and Hong Kong. The origin of the outbreak was a laundry worker aged 42 years with diabetes mellitus and peripheral vascular disease who was employed at hospital A. On April 12, 14, and 15, he had a fever and diarrhea and was evaluated in the emergency department. The patient remained on duty and interacted frequently with patients, staff, and visitors. The patient had

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