1.1 Standard infectious ward layout
Originally, there were two wards on each floor, located in the East area and West area with a corridor between them. Thus, the doors in the elevator area were blocked to connect the East and West areas as a whole. Two additional doors were added to the original staff passage in the West area and the original patient corridor in the East area to form two buffer zones, forming a polluted area—buffer room—semi-polluted area— buffer room— cleaning area layout (from west to east). The West district served as a contaminated area ward for critically ill patients with COVID and for removing the outermost protective equipment. The section between West ward and East ward formed a semi-polluted area, where medical care workstations, dispensing rooms, warehouses, and staff toilets were set up. Staff also took off inner clothing here. The East ward was set up as the staff-only clean areas, which are used by staff to don protective equipment and store materials and as staff living areas (Figure 1). The old staff passageway in the East district was retained as the staff passageway, and the original dirt elevator, located in the west ward, was converted into a patient passageway. The original patient access door was blocked, and a continuously running air curtain was installed near the ceiling above the door to promote the air to flow from the clean area to the polluted area.