He told a press conference that five of the seven cases detected Thursday are linked to the cluster infection in the Singapore General Hospital (SGH).

Cluster infection in the SGH broke out last Saturday when a total of 21 SGH staff members from Wards 57 and 58 developed fever.

Epidemiological investigations have traced the source of this cluster of infections to a man who had suffered from chronic kidney disease and diabetes and had been admitted to the Tan Tock Seng Hospital (TTSH), which is designated for treating SARS.

The old man was later admitted to SGH Ward 57 and transferred to Ward 58 afterwards.

But doctors noted that the clinical picture of the old man is not typical of SARS and it is likely that the typical symptoms of SARS were masked by his other underlying medical conditions.

The minister said that the SGH cluster of infections bears the implications that one key thrust is to identify symptomatic cases as early as possible, paving the way for timely treatment and isolation.

He indicated that the precautionary measure to trace and ring-fence close contacts with SARS patients significantly helps reduce any further transmission of SARS, especially to the community at large.

Lim also called for lifting infection control requirements in all hospitals.

The types of cases that hospitals need to identify early and isolate have been widened to include all cases of atypical pneumonia and fever without a known cause, as well as health care workers who show fever and/or respiratory symptoms of undetermined cause, he said.

(Xinhua News Agency April 11, 2003)