SINGAPORE: A student from Jurong West Secondary School was incorrectly diagnosed with COVID-19, after Tan Tock Seng Hospital (TTSH) mislabelled testing samples.
"The original test was undertaken by our laboratory. Subsequently, the student was admitted to NUH and re-tested twice and found to be negative on both occasions. Our laboratory repeated a PCR test on the original sample and the result was negative," said TTSH in a media release on Tuesday (Jul 14).
"Our investigations revealed that there was an erroneous reporting of this case by our laboratory. This arose from a human error in the laboratory where two patients had their specimens cross-labelled."
The Ministry of Health (MOH) added that the laboratory had "mislabelled" a swab sample because it did not properly verify the "patient identifiers of the specimen tubes".
MOH said it was notified of the error on Monday, three days after the student, a 13-year-old girl, was reported as a COVID-19 case.
READ: Student at Jurong West Secondary contracts COVID-19, case is linked to another student at the school: MOE
The student is "otherwise well" and has been discharged, said the hospital.
According to the Ministry of Education (MOE) on Saturday, the girl's case was linked to another student at the school.
With the reclassification of her case, MOE said on Tuesday that there is no second confirmed case of student-to-student transmission.
MISLABELLED POSITIVE SAMPLE BELONGS TO MIGRANT WORKER
The mislabelled positive sample belongs to a migrant worker who had been isolated since his swab, said MOH, adding that he had not been in contact with any other individuals. He is currently well, the ministry said.
As for the student, MOH said she had so far been isolated and "had not come into contact with any other COVID-19 patients and is therefore not at risk of infection from other patients in the hospital".
It also rescinded the quarantine orders of the close contacts in relation to this erroneous case.
"We have since informed both patients of the mislabelling incident and apologised for the anxiety caused," said TTSH.
"We are sorry for the mistake and sincerely regret the inconvenience caused to our patients and her school," it added.
"We have audited our laboratory testing for COVID-19 for that period and no other mislabelling was discovered. We have also put in place additional checks to prevent such an incident from occurring again."
MOH INVESTIGATING MATTER
In a Facebook post on Tuesday, Education Minister Ong Ye Kung noted his relief when the positive case turned out to be incorrectly diagnosed.
"On Jul 10, all of us at MOE were dismayed when we learnt that at Jurong West Secondary School, a student who caught the COVID-19 virus at home, has infected another classmate," Mr Ong said.
"This would have been our first recorded COVID-19 infection in school, despite all our precautionary measures," he added.
"We will not let up. Schools will take all necessary measures to keep schools safe, and allow learning to go on as much as possible."
Referring to the first infection in the school, which involved a 13-year-old boy, director of schools for MOE Liew Wei Li said all 71 students and staff members who were close contacts of that case have tested negative.
MOH said it takes a serious view of the error by the TTSH lab.
"We are investigating this matter, and will take appropriate actions against the laboratory if it is found to be in breach of protocols," said the ministry.
"In the meantime, the laboratory has reviewed and tightened its processes to prevent a recurrence of the error."