Sep 9, 2003 (CIDRAP News) – A 27-year-old Singapore man has twice tested positive for SARS (severe acute respiratory syndrome) and is regarded as having a probable case, even though the case doesn't meet the World Health Organization (WHO) definition, the Singapore Ministry of Health said today.
If the case is confirmed, it will be the first SARS case since the WHO declared SARS contained Jul 5. "In view of his positive PCR [polymerase chain reaction] and serology results, MOH [Ministry of Health] is treating him as a probable SARS case," the Ministry of Health said in a statement.
However, "WHO has informed us that the case does not fulfill the case definition for SARS under the new WHO guidelines post-SARS," the statement said.
The agency said PCR and serology tests yesterday were positive for SARS. A second PCR test today was also positive, the statement said. The patient has no history of travel to previously SARS-affected areas and no known contact with SARS patients. The source of the infection is under investigation, officials said.
The patient is currently in isolation at the Singapore Communicable Disease Centre. "His contacts have largely been followed up and all of them are well," the ministry said. The agency has ordered 25 contacts into home quarantine.
The statement said the man is a post-doctoral student who works on West Nile virus at a microbiology laboratory at the National University of Singapore and also works in a lab at the National Environment Agency. He became ill with a fever late on Aug 26 and saw a general practitioner, who prescribed antibiotics. When the fever persisted, he went to Singapore General Hospital Aug 29. A chest x-ray was normal, and he was sent home with a diagnosis of viral fever.
The man returned to the hospital Sep 3 and was admitted, the statement said. At that point he had fever and muscle and joint pain but no respiratory symptoms; later he experienced a dry cough. When he tested positive for SARS yesterday, he was transferred to the Communicable Disease Centre.
The Ministry of Health said the two labs where the man works have suspended all their research and the staff members have been asked to stay home until further notice. All the staff members are well, the statement said.
An Associated Press report said WHO spokesman Dick Thompson called the lab test results "perplexing" and said more tests need to be done, preferably in another country. Thompson said precautions for SARS are in order even though the case doesn't fit the WHO definition. He also noted that the patient may have had some exposure to viruses in his work.
By the WHO definition, a person has a "suspect" case of SARS if he or she has a high fever, cough or breathing difficulty, and a history indicating possible exposure to the disease. A case is considered "probable" if the patient meets the suspect-case criteria and either (1) has radiographic signs consistent with pneumonia or respiratory distress syndrome or (2) tests positive for the SARS coronavirus by one or more assays.
WHO SARS case definitions