SINGAPORE - In a statement late on Wednesday night, the Ministry of Health outlined the events leading to the announcement earlier this week by Singapore General Hospital about the spread of the Hepatitis C virus among at least 21 patients in one of its wards.

Eight of the infected patients have died, with five deaths possibly linked to the Hepatitis C infection.

The ministry was responding to media queries on what actions were taken after SGH reported to MOH in late August that it had identified a cluster of 21 Hepatitis C cases and suspected they were linked.

MOH outlined the events thus:

Sept 3: Associate Prof Benjamin Ong, the Director of Medical Services (DMS) met with SGH clinicians.

SGH informed Dr Ong that the cluster of 21 patients had tested positive for the same hepatitis C genotype 1B.

Preliminary phylogenetic studies (a specialised genetic test to identify the different sub-types of Hepatitis C virus) by the hospital showed the Hepatitis C virus in the patients were related.

The hospital had taken control measures and there were no further cases after June 24.

Dr Ong requested for:

a) External representation on two committees which SGH was setting up: the Medical Review Committee (MRC) to review clinical matters and the Quality Assurance Review Committee (QARC) to review infection control and patient safety processes;

b) External verification of SGH's phylogenetic analysis by an A*STAR laboratory as this was the first time the SGH had conducted such an analysis;

c) He asked the hospital to prepare a mitigation plan with attention to screening of healthcare staff's Hepatitis C status; and

d) A team from MOH to visit the affected ward to perform a process walk-through with SGH's staff.

He asked that the work be done in no later than two weeks.

MOH nominated Prof Teo Eng Kiong, Chairman of Medical Board of Changi General Hospital and a gastroenterology and liver disease specialist, to chair the medical review committee, and Dr Serena Koh, Deputy Director, Clinical Quality, Performance and Technology Division, MOH, to be a member of the quality assurance review committee.

Sept 4: An MOH team visited the renal ward (Ward 64A and 67) for a process walk through with SGH.

Sept 7: External verification of SGH's phylogenetic analysis by an A*STAR laboratory was completed and confirmed SGH's initial findings that the 21 cases were related.

Sept 9: SGH commenced Hepatitis C screening for all doctors and nurses involved in the direct care of the affected patients. As of Sept 25, 76 staff members were screened. All were found to be negative for Hepatitis C.

Sept 18: Having assessed that the additional investigations requested had largely been completed, Dr Ong reported the matter to the Minister for Health. Minister Gan Kim Yong asked for a briefing from the hospital. SGH requested for it to take place on Sept 25 to allow sufficient time for the two committees to complete their investigation and submit their report to MOH.

Sept 21: MOH was notified of the 22nd case.

Sept 24: SGH submitted its report to MOH.

Sept 25: Mr Gan instructed that an independent review committee be set up, and for SGH to make public its preliminary findings.

Sept 28: An independent review committee was set up comprising respected clinicians from different disciplines. Dr Jeffery Cutter, Director, Communicable Diseases Division, MOH is a representative on the committee.

Oct 6: SGH conducted a media briefing and MOH released a press statement.

The statement on Wednesday by a ministry spokesman said, "In the investigation, the primary consideration has been to try to get to the root cause of the issue as soon as possible, exploring all possible angles, to prevent recurrence.

At the same time, the teams from SGH and MOH were mindful of the need to make public the cases as soon as preliminary investigations were completed."

In response to other queries, MOH said the cause of the infections is still under investigation.

"It is not yet conclusive that the use of multi-dose vials is the cause of the Hepatitis C infection in this incident," the spokesman said.

Both single-dose and multi-dose vials are used in Singapore's public hospitals, the spokesman added. However, special preparations and safety protocols are put in place when using multi-dose vials, as the potential risk of contamination is higher.

MOH also said that it had previously been notified by the SGH laboratory of the cases as all acute Hepatitis C infections must be reported within 72 hours.

However, as the patients did not have symptoms such as jaundice, the cases were not classified as acute and therefore were not flagged in its weekly infectious diseases bulletin.

MOH said it had reclassified those cases and would update the bulletin.