TAIPEI (Taiwan News) — Two residents of Keelung City, an Indonesian caregiver and a Taiwanese woman on Friday (Oct. 22) tested positive for COVID-19.
Health Minister and CECC head Chen Shih-chung (陳時中) confirmed that case No. 16,461 is an Indonesian woman in her 30s who has been working in Taiwan for a long period of time. At the request of her employer, she was tested for the virus on Oct. 20 and the result came back positive for COVID-19 on Oct. 22.
She was found to have a Ct value of 33 and a blood test showed a positive result for antibodies. The health department has identified seven contacts in her case, all of whom have entered isolation.
Case No. 16,462 is a Taiwanese woman in her 50s who was tested for the virus because she accompanied a hospital patient. She developed symptoms of fatigue that same day.
She was diagnosed with COVID-19 on Oct. 22 with a Ct value of 33.2 and a positive result for antibodies. The health department has identified 10 contacts in her case, all of whom have entered isolation.
Lo Philip Lo (羅一鈞), deputy head of the CECC’s medical response division, said that the center has not yet found any connection between the two cases. Lo said that a member of the family that the woman was working for had been diagnosed with COVID-19 on May 20.
At the time, the health department did not believe the woman had come in contact with the confirmed case during the infectious period and did not require her to undergo isolation. However, Lo pointed out that in May the sudden surge in COVID cases prevented the center from carrying more thorough epidemiological investigations.
Lo said the caregiver may have come in contact with the infected family member before or after the family member's diagnosis back in May. He said that this week, the woman tested negative for IgM antibodies and positive for IgG antibodies indicating that she is in the recovery phase and had been infected for quite some time.
The CECC believes it is likely that the woman contracted the disease in late May is "relatively high." He said that it is possible that a member of the family or someone in her community transmitted the disease to her, but as she has been asymptomatic throughout it is difficult to determine exactly when she contracted the virus and how.
As for case No. 16,462, Lo said that she had not come into contact with any known cases, but based on the results of her PCR test and antibody tests, she had also acquired the disease at some point in the past.
When asked if either case is classified as a breakthrough infection, Lo said the Indonesian national had received one dose of the Medigen vaccine in late August and a second in late September, while the Taiwanese citizen had received one dose of the BNT vaccine in mid October.
Lo said that based on a preliminary investigation, the center does not consider case No. 16,461 to be a breakthrough case because it appears likely that she contracted the virus in May, three months before she received her first vaccine dose. Nevertheless, Lo emphasized that a full epidemiological investigation will be carried out to determine exactly when she contracted the virus and whether she should be classified as a breakthrough case.
The cycle threshold (Ct) value refers to the number of cycles the fluorescence of the PCR test is detectable. Generally, the higher the number, the longer the virus has gone undetected, while the lower the number, the more recent the infection likely occurred.
Antibody tests are used to determine whether a COVID-19 infection has occurred, what stage it has reached, and whether a person could still be infectious. If a person is negative for both IgM and IgG antibodies, there is no evidence of infection.
If IgM is positive and IgG is negative, it indicates the patient is at an early stage of the disease. If IgM is positive and IgG is positive, the patient is likely at the intermediate stage of the disease, while a negative IgM and a positive IgG signifies that the patient is in the recovery phase and is not infectious.