An outbreak of Salmonella Typhimurium, across England and Wales that was announced earlier this month has now grown to 57 confirmed cases, ranging from an eight-month-old baby to an 87-year-old pensioner.
Nine people have so far been treated in hospital.
The outbreak was first detected in Wales in August and centred mainly in North Wales (Conwy and Gwynedd), with additional clusters being investigated in England in the Thames Valley, Leeds, Cumbria and Stafford areas.
Consumption of cooked ham from small independent butchers has been identified as a potential common link to the illness.
Testing has been carried out on ham supplied to a number of butchers identified in the investigation. No trace of salmonella has been found, but other hygiene issues were identified that led to one supplier voluntarily withdrawing certain batches of ham. Investigations are on-going.