The HPA, which sampled 133 cloths from 120 establishments in north east England, said 56 per cent of the cloths contained “unacceptable” levels of bacteria. The most common were Entereobacteriaceae (found on 86 cloths), E.Coli (21 cloths) Staphyloccus aureus (six cloths) and Listeria (five cloths).
And although the recommended advice for restaurants is to use disposable cloths that are changed regularly, the study found that only a third (32 per cent) of the catering premises adhered to this. The remaining two thirds (68 per cent) used re-useable cloths and 15 per cent were unsure as to how often these were replaced.
The research also found that 24 of the cloths had been used between raw food areas and ready-to eat areas, despite the HPA advising that the cloths should be kept separate.
Dr John Piggott, the lead author from the HPA's Food, Water and Environmental Microbiology laboratory in Leeds said: "It's of concern that despite recommendations to use disposable cloths the majority of restaurants we surveyed were re-using cleaning cloths and some were unaware how often they changed them.
"Although many disinfected their cloths using bleach or other disinfectants, soaking does not remove the food on which the bacteria grow. The disinfectant qualities of bleach do wear off after a period of time so soaking large amounts of cloths together can result in bacteria contaminating more cloths and creating more potential problems.”
The presence of Listeria species on five of the cloths shows a potential hazard for restaurant and take-away owners, as it is less sensitive than other bacteria and can infect vulnerable people at relatively low levels. Listeria monocytogenes, found on three of the cloths, can cause serious illness.
E. coli, found on 21 of the cloths, can signify that faecal pathogens are present, while Staphlycoccus aureus has the potential to cause food poisoning and Enterobacteriaceae include species that originate from the intestinal tract of animals and humans.