Figure 2.

Path of infection of influenza (H5N1), Pakistan, 2007. During October 22–30, patient 1 worked culling infected chickens; on November 2, he moved home and had contact with 4 brothers (patients 2–5) and possibly a cousin (patient 6). He was hospitalized on November 5 and transferred to an intensive care unit the next day. His cousin cared for him and became patient 6; his attending doctor became patient 7. On November 23, patient 3 was hospitalized and on November 28 was transferred to an intensive care unit; during this time, patient 8 frequently visited his wife in the same intensive care unit.