Updated at 6.41pm: A survey released by the Food and Environmental Hygiene Department on Thursday showed that the bacteria content in shop-bought sandwiches has declined since 1997.
Department consultant Dr Ho Yuk-yin said: 'trend analysis has revealed steady improvement in the overall hygienic quality, with the unsatisfactory rate dropping from 11.3 per cent in 1997 to 8.5 per cent in 1998 and 3.8 per cent in 1999.''
Despite the drop the Department said there were a few areas of concern, and that people should take extra care with sandwiches containing salad, as they were more prone to contamination.
Dr Ho advised consumers to buy sandwiches from reputable suppliers and consume the sandwiches as soon as possible.
''Prepared and home-made sandwiches should be properly stored at zero to four degree Celsius and consumed within one to two days,'' he added.
Six of the 1,023 samples tested from 1997 to 1999 were found to contain specific pathogens: one in 1997, five in 1998 and none in 1999. The pathogens isolated were Salmonella organisms (3 cases), Listeria monocytogenes (2 cases) and Staphylococcus aureus (1 case).
