Sep 23, 2003 (CIDRAP News) An international review panel has concluded that the Singapore man who had the world's first new SARS (severe acute respiratory syndrome) case since the end of the outbreak probably acquired the virus in a government laboratory where he worked, the Singapore Ministry of Health announced today.
The 11-member committee determined that the 27-year-old man most likely acquired the virus in the Environmental Health Institute laboratory, the ministry said in a news release. The man had a job doing research on West Nile Virus at the National University of Singapore, and he also did some work on West Nile at the environmental lab, where others studied the SARS virus.
"Inappropriate laboratory procedures and a cross-contamination of West Nile virus samples with SARS coronavirus in the laboratory led to the infection of the doctoral student," the ministry said. "No evidence could be found of any other source of infection." Genome sequencing of the virus strain used in the laboratory and virus isolated from the patient showed that the two were closely related, the ministry said.
The ministry also said the panel determined that there is no evidence that the man transmitted the virus to anyone else. He was released from a hospital last week.
The committee's report says the man worked in the environmental lab Aug 23, 3-1/2 days before he became ill, which fits the expected incubation period for SARS. Polymerase chain reaction testing of the frozen specimen the man worked with that day was positive for both West Nile virus and the SARS virus, indicating cross-contamination, the report states.
The panel also examined Singapore's four laboratories rated as biosafety level 3, the second highest of four risk categories. The group found structural problems as well as training and record-keeping deficiencies at the environmental health lab and recommended that the lab not reopen until the problems are corrected. Lesser problems were found at the Singapore General Hospital laboratory and the National University of Singapore laboratory.
The patient, a microbiology student, became ill Aug 27. The health ministry announced Sep 9 that he had tested positive for the SARS virus, and the finding was later confirmed by tests at the US Centers for Disease Control and Prevention (CDC ).
The review panel was chaired by Dr. Antony Della-Porta, a World Health Organization biosafety expert, and included two CDC representatives.