The department of the Food and Environmental Hygiene Department (FEHD) conducted 388 samples from 200 locations between January and June this year.
Food needs to be properly handled by taking steps such as keeping perishable foods in a refrigerator at four degrees Celsius or below and avoiding cross-contamination, said the agency.
"In the past two years, the Centre for Health Protection (CHP) has recorded an increasing number of Listeriosis cases. This disease is usually caused by eating food contaminated with Listeria monocytogenes and may pose significant health risks to pregnant women, newborns, elderly and those with a weaker immune system," a spokesman for CFS said.
"Although Listeria monocytogenes can be killed under normal cooking temperatures, it may continue to grow slowly at refrigerated temperatures as low as zero degree Celsius. This characteristic makes refrigerated ready-to-eat food with a long shelf life (longer than five days) a potential high-risk item for Listeriosis.”