To select the environmental sites to be sampled in each LBM, the study advisory team visually inspected 3 markets and reviewed the literature to identify LBM sites commonly contaminated with AIVs or similar pathogens. Sites sampled in previous studies for AIV included fl oors, drains, and water troughs (8, 11, 12) . In this study, 27 sites were selected for environmental sampling ( Table 1) . The sites represented different poultry-related work activities: 3 sites related to delivery of birds into LBMs, 7 in the birdholding zone, 9 in the slaughter zone, 6 in the sale zone, and 2 in the waste-disposal zone. Because of variation in LBM infrastructure and processes, each LBM did not necessarily have all 27 sites. Samples were collected from as many of the 27 sites as were available in each LBM.