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Taiwan scientist bitten by mice twice before testing positive for COVID

Researcher developed COVID symptoms one week after 2nd mouse bite

(iStock photo)

(iStock photo)

TAIPEI (Taiwan News) — A scientist at a high-level biological safety lab in Taipei was bitten twice by mice before testing positive for COVID, prompting an investigation into whether laboratory rodents were the source of her infection.

During an emergency press conference on Thursday evening (Dec. 9), Central Epidemic Command Center (CECC) head Chen Shih-chung (陳時中) confirmed that a female laboratory researcher in Taipei City tested positive for COVID.

Chen identified her as case No. 16,816, a woman in her 20s, who worked at Academia Sinica. She is considered to be a breakthrough case, having been fully vaccinated with Moderna, though it was confirmed she has the Delta variant of the virus.

Chen said she was "exposed to the pathogen" in mid-November while working at Academia Sinica's Genomics Research Center, which houses a P3 (Biosafety Level-3) facility in Taipei's Nangang District. At a press conference on Friday (Dec. 10), Deputy Mayor Huang Shan-shan (黃珊珊) described the woman as a "research assistant" and said that on Oct. 15, she had been bitten by a lab mouse.

She subsequently took a rapid antigen test, which came back negative. On Nov. 19 she was again bitten by a mouse in the lab, but did not undergo testing for the coronavirus, for unexplained reasons.

On Nov. 26 she had a slight cough and her coughing intensified on Dec. 4, but she did not seek medical attention. She then had problems with her sense of smell and taste on Wednesday (Dec. 8).

The same day, she underwent a PCR test and the result came back positive for COVID on Thursday (Dec. 9), with a Ct value of 15.17. She resigned from her position on Dec. 3, meaning that she quit her job and went straight into the community while already exhibiting symptoms.

She did not report these symptoms for five more days, missing an opportunity to catch her infection sooner. According to Apple Daily, one of the mice was infected with the Alpha variant of the virus, while the other mouse had been infected with the Gamma strain.

However, preliminary genomic sequencing found the woman contracted the Delta variant. When asked to comment on how the woman could have contracted Delta from mice that were infected with other variants, Chen emphasized that there has not yet been a full investigation into what specific variants the mice were infected with.

Chen said that based on a preliminary assessment, the variant found in the lab and the one the woman had contracted were a match. As to "which mouse had been handled and which had bitten the woman," Chen said that further investigation is necessary before the details can be clarified.

He said the thrust of the investigation will be to determine whether the sequence of the virus strain detected in the lab is the same one that infected the woman. If that is the case, Chen said the center can conclude that her infection came from the lab.

Chen said that process must be taken one step at a time and that "right now we're not investigating mice, we're investigating people." When asked if this marked the first infection in a biological laboratory in Taiwan, Chen confirmed that this was the first time a COVID-19 infection had been reported in a lab.