Six other exposures approached signifi cance, either as protective factors or as risk factors. LBMs that disposed and removed solid waste daily (OR 0.41, 95% confi dence interval [CI] 0.16-1.09); had zoning that clearly segregated poultry delivery, holding, slaughter, sale, and wastedisposal areas (OR 0.28, 95% CI 0.07-1.11); or stacked poultry cages vertically rather than side by side (OR 0.38, 95% CI 0.13-1.10) had less risk for avian infl uenza virus (H5N1) contamination. LBMs with pigeons (OR 3.06, 95% CI 0.96-9.81), mixed bird species in the same cages (OR 2.92, 95% CI 0.98-8.70), or slaughtered birds in the market (OR 3.53, 95% CI 0.89-13.93) were more likely to be contaminated.