TAIPEI (Taiwan News) — The head of the Central Epidemic Command Center (CECC) said that a case dubbed "Egypt Dad" by local media was the first to be diagnosed with COVID-19 in a New Taipei Delta cluster infection, but stressed that more investigation is required before the source of the outbreak can be confirmed.
During a press conference on Thursday (Sept. 9), Health Minister and CECC chief Chen Shih-chung (陳時中) announced that a cluster infection that initially spread through a kindergarten and later expanded to an apartment tower in New Taipei City has risen to 27 cases. When asked to provide an assessment on the index case of the cluster, Chen said that a kindergarten teacher (Taiwan's COVID case No. 16,129) and the "Egyptian Father" of a kindergarten student and recent returnee from Egypt (case No. 16,160) are both likely candidates because they were the earliest to be diagnosed.
Chen said that the antibodies detected in the bloodstream of the Egyptian national and his Taiwanese wife (case No. 16,155) indicated that they may have been infected longer than other cases. Both tested positive for IgG and IgM antibodies, signifying that they are well into the intermediate phase of the disease.
He said that the couple's Ct value from their PCR tests, particularly the man's, were higher than other cases, meaning they had probably been infected earlier. However, he stressed that because their IgM is still positive, they could not have been infected for much longer than the other cases.
Given that a renovation worker and his wife were the latest cases reported from the apartment building cluster on Thursday, a reporter asked if it was possible cases had contracted the virus from public spaces in the two hotspots. Chen said that tests on samples taken from the kindergarten and apartment tower had all come back negative.
Diagram showing cases from Delta cluster infection tied to kindergarten and apartment. (Taiwan News, Yuwen Lin image)
The cycle threshold (Ct) value refers to how many cycles at which fluorescence of the PCR test is detectable. The higher the number of cycles, the longer the virus had gone undetected, while the lower the cycle number, the more recent the infection had occurred, and therefore the higher the viral load.
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.