Abstract

Due to the recent COVID-19 pandemic, Legionellosis is concern when buildings are re-opened after long periods of unoccupied situation. In this study, the status was reviewed through Legionella contamination issues and cases in building water systems before and after the COVID-19 pandemic. As a result, energy-saving buildings were vulnerable to microbial contamination such as Legionella spp., so temperature and water age of the system should be properly designed and maintained. In addition, since flushing or thermal disinfection is only ad-hoc approaches in unused buildings during the COVID-19 pandemic, monitoring and follow-up through overall inspection is required before re-operation of the building water systems. To prevent Legionellosis, which are concern in the post COVID-19 period, building water systems should be maintained with more pro-active approaches.