More than 100 cases of a certain type of Salmonella have been identified since the beginning of August, when normally only ten cases would be found.
A further 19 cases have been found in Scotland.
Investigations have found the bug is present in some bags of bean sprouts.
Ten people fell ill with Salmonella poisoning at a wedding in Manchester in August and an 82-year-old woman died.
Professor Qutub Syed from the HPA’s Local and Regional Services Division said: “It is important for people who prepare meals in catering establishments and in the home to keep raw bean sprouts separate from other salad products, including ready-to-eat bean sprouts, to avoid the risk of cross-contamination.
“If there is any doubt as to whether bean sprouts are “ready-to-eat”, or in the absence of clear preparation instructions, the Food Standards Agency advises that bean sprouts should be washed and thoroughly cooked as a precaution. If this advice is followed bean sprouts will be safe to eat.”