Figure 4
From: Airborne spread and infection of a novel swine-origin influenza A (H1N1) virus
Arrangement of the isolators applicable to pigs and guinea pigs. Animals in inoculation group (GA) and direct contact group (GB) were housed in the isolator A, and animals in aerosol infection group (GC) were housed in the isolator B. The two isolators were connected with a tube(2 m) which allowed the air flowed from A to B. SH is a sampling hole from which air samples were collected. F1 is a positive pressure fan and F2 is a negative fan. The air flowing through the two fans was filtered to remove microorganisms.