Tainan City Government announced one retroactively added case (Case #6799), who is an over 30-year-old female from Indonesia as well as the household member of previously announced Case #2355 and Case #2428 in Tainan. Because Case #6799 used to take care of Case #2355, she has implemented home isolation since May 18 with an initially negative test result. She experienced the onset of cough and fever on May 26 and was arranged for undergoing test in a hospital and then was confirmed as the COVID-19 case. No contact was identified as Case #6799 was under home isolation from May 18 to May 26.