Studies in Hong Kong Special Administrative Region, People's Republic of China; other areas of China; Indonesia; and the United States have shown that LBMs can harbor avian infl uenza viruses (AIVs), including highly pathogenic infl uenza virus A (H5N1), and have been associated with human infection (4) (5) (6) (7) (8) (9) . Continual movement of birds into, through, and out of markets provides opportunity for the introduction, entrenchment, and dissemination of AIVs. Most studies have focused on testing live birds rather than environmental sites in the LBMs (6, 7, 10) . However, a study in New York, NY, that tested environmental sites for AIV (H7N2) found that virus could be isolated from samples from fl oors, walls, and drains from the poultry areas of LBMs (8) . The study also found that despite the ongoing infl ux of infected birds into LBMs, the level of environmental contamination decreased with routine cleaning and disinfection. Another study in Hong Kong LBMs showed that AIV (H9N2) could be isolated at higher rates from poultry drinking water than from samples of bird fecal droppings (11) . Environmental aspects of LBMs are needed for an avian infl uenza control program for 2 reasons. First, a contaminated environment can provide a continuing source of virus transmission, in which healthy birds coming into the market may become infected and persons working in or visiting the market may also be exposed. Second, ongoing surveillance programs in LBMs based on environmental sampling are more likely than those based on invasive bird testing to be acceptable to traders and stall vendors. Environmental sampling is also safer for public health offi cers and veterinary health offi cers than handling and sampling live birds that may be infected with AIV.