The high levels of Salmonella contamination sug- gest that is there remains a problem with the quality of the pork being sold in retail outlets within the Chiang Mai study zone and that this important public health situation appears changed from the study conducted a decade ago. Since the desired precision for sample size determination in the study is large (i.e. 10%) leading to a small sample size in the study, the observed prevalence of Salmonella contamination in Chiang Mai may not be representative