Control measures for severe acute respiratory syndrome in Taiwan - SARS - Dispatches

Emerging Infectious Diseases, June, 2003 by Shiing-Jer Twu, Tzay-Jinn Chen, Chien-Jen Chen, Sonja J. Olsen, Long-Teng Lee, Tamara Fisk, Kwo-Hsiung Hsu, Shan-Chwen Chang, Kow-Tong Chen, I-Hsin Chiang, Yi-Chun Wu, Jiunn-Shyan Wu, Scott F. Dowell

As of April 14, 2003, Taiwan had had 23 probable cases of severe acute respiratory syndrome (SARS), 19 of which were imported. Taiwan isolated all 23 patients in negative-pressure rooms; extensive personal protective equipment was used for healthcare workers and visitors. For the first 6 weeks of the SARS outbreak, recognized spread was limited to one healthcare worker and three household contacts.

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The global spread of severe acute respiratory syndrome (SARS) has proceeded with unprecedented speed, overwhelming many hospitals and some public health systems in a matter of weeks. As of April 14, 2003, a total of 3,169 cases had been reported from more than 20 countries. In many locations, the introduction of the disease by ill travelers has soon been followed by spread to healthcare workers and household contacts. In the most mature outbreaks, in Hong Kong and Hanoi, 46% and 63% of cases, respectively, were reported in healthcare workers, and hospital spread has also characterized the larger outbreaks in Singapore and Toronto (1,2).

Taiwan, with its close proximity to the epicenters of severe acute respiratory syndrome (SARS) in Guangdong Province and Hong Kong and its extensive business and cultural ties, has heavy travel volume from the most affected areas. The first probable SARS case-patient in Taiwan returned from Guangdong and Hong Kong early in the global outbreak, on February 21, 2003, and a series of other importations have been documented since that time. Factors that contribute to spread of infection in a given location are not well understood but may include not only the number of coronavirus-infected persons but also whether any of these persons are particularly infectious, whether they are identified early in their illness, and how effectively they are isolated. To contribute to discussions on how to effectively prevent transmission, we believe reporting the early experience with limited spread of the disease in Taiwan, along with a thorough description of the control measures taken, is important.

Epidemiology of SARS in Taiwan

The first recognized SARS patient in Taiwan was in a 54-year-old businessman who traveled to Guangdong Province, China, on February 5, 2003, and returned to Taipei by way of Hong Kong on February 21. On February 25, fever and myalgia, and later a dry cough, developed, but he was not hospitalized until March 8. Several hours after admission, he was intubated and required mechanical ventilation for 13 days. During the initial hospitalization, he was cared for in a single intensive care unit (ICU) room by healthcare workers who used standard nursing (universal) precautions. When pneumonia was diagnosed in the patient's wife on the morning of March 14, both patients were placed in isolation rooms; by the afternoon they were isolated in ICU negative-pressure rooms with full precautions, as described below. Fever developed in their son on March 17, followed by cough on March 20; he was hospitalized in a negative-pressure isolation room on March 21. The wife and son were exposed during the period before full protective measures were in place, and SARS developed in both. Both required mechanical ventilation. The illnesses in the wife and son were confirmed by reverse-transcription-polymerase chain reaction (RT-PCR) testing to be associated with the novel SARS coronavirus (3-5).

As of April 14, 23 persons in Taiwan met the World Health Organization (WHO) criteria for a probable case of SARS. Of these, eight had SARS-associated coronavirus identified in throat swabs by PCR. An additional 120 reports of possible case-patients with compatible travel or contact were investigated, and 13 remained under investigation. Of the probable case-patients, 19 (83%) reported travel to mainland China and Hong Kong in the 10 days before illness onset, and 4 represented secondary spread. The patients with secondary cases included the two family members described above, a person who acquired it in his household from a Hong Kong visitor (representing 13% of cases), and a single healthcare worker (representing 4% of cases).

The single case in a healthcare worker was in a 32-year-old physician who cared for the wife of the initial case-patient. On March 14, the physician had performed a chest ultrasound that lasted approximately 30 minutes; he spent an additional hour in the room on March 17 during and after intubation. He was at the side of the bed supervising the intubation and in a direct line of droplet spread when the patient had episodes of coughing, sometimes partially sitting up. The physician reported wearing an N95 mask, eyeglasses without goggles, two pairs of gloves, and two gowns. His illness began on March 21, with clinical features that met the criteria for a probable SARS case and laboratory confirmation of coronavirus infection by RT-PCR. None of the other five persons present in the room for the intubation became ill after 28 days of follow-up.

SARS Control Measures in Taiwan

Beginning with the recognition of the first SARS case on March 14, Taiwan moved aggressively to isolate all suspected or probable case-patients in negative-pressure rooms and to equip all healthcare workers with enhanced protective equipment. Assistance from the U.S. Centers for Disease Control and Prevention (CDC) was requested, and a team has worked with Taiwan Center for Disease Control officials since March 16 to implement a framework for SARS control.