TAIPEI, Taiwan — Health authorities in Taiwan are quarantining 5,000 people while looking for the source of two new coronavirus cases linked to a hospital.

Officials said on Monday that they have not been able to identify how the husband and wife became infected after a brief hospital stay in the Taoyuan General Hospital, located in the city of Taoyuan just outside Taiwan’s capital city. The man had stayed at the hospital for three days for health problems unrelated to COVID-19, while his wife looked after him.

Those asked to quarantine include patients who were discharged from the hospital from Jan. 6 to 19, and their caregivers.

Taiwan is on higher alert after the latest domestic cluster, which has now seen 15 cases from the hospital in Taoyuan.

Taiwan has been applauded for its swift and sustained efforts to contain COVID-19, with just seven deaths and fewer than 900 confirmed cases, despite its close proximity to China, where the pandemic began.