Food law enforcement plan

Investigation and Control of Outbreaks, Food Related Infectious Disease and Zoonoses

3.7.1 Investigation and control of outbreaks and food related infectious disease

Since 1st April 2017, notifications of food poisoning and food related infectious disease have been received by the Health and Safety Team instead of the Food Safety and Standards Team.
This transfer of responsibility was made in part to respond to mounting pressures on the Food Team, relative to Health and Safety, and partly to establish better alignment of areas of infectious disease control.
Food Officers will continue to investigate food premises implicated in suspected food borne incidents, as is currently the case, but not incidents which are evidently spread person to person or of other environmental origin.
In practice notifications come from GPs and medical laboratories, via an appointed proper officer situated within the Mid and West Wales Health Protection Team (part of Public Health Wales). These notifications are made in accordance with the Health Protection (Notification) (Wales) Regulations 2010.

The Authority has appointed a Lead Officer for Communicable Disease Control, and works closely with appointed proper officers (Consultants in Communicable Disease Control or Consultants in Health Protection) employed by Public Health Wales.
In practice, notifications are received electronically via a shared database system (Tarian), utilised by local authorities, Public Health Wales laboratories and local Health Protection Teams.
Reported cases of ‘gastro-intestinal infections’ are generally investigated by the Health and Safety Team with a view to determining the source of infection where possible; so that advice can be provided and/or action taken to prevent further spread; and, to identify any steps that can or should be taken to prevent future occurrences.

The protocols for investigating sporadic cases are covered by internal procedures, and outbreaks are investigated in accordance with the All Wales Outbreak Plan, which provides the agreed framework for consistent, multi-agency investigations.
Response targets for both sporadic cases and outbreaks reflect those established in the ‘Public Health Wales – Notification Guidance Reporting from Microbiology Laboratories on Organisms - July 2011’.
Investigations typically involve case interviews and the provision of advice, but depending on the cause and source of infection, and risks involved, may require a variety of follow-up actions including:

  • Ensuring the exclusion of persons infected from high risk settings (typically schools, nurseries, food premises, and health care settings).
  • Screening samples from other persons exposed.
  • Follow-up samples from confirmed cases to provide microbiological clearance.
  • Visits to at risk settings such as schools, nurseries and other childcare settings, and to residential care and nursing homes, to provide advice on infection control.
  • Visits to food business premises, where food purchased by, or provided to, consumers might be implicated.
  • Obtaining food and/or environmental samples.
  • Liaising with other local authorities and central competent authorities, e.g. the Communicable Disease Surveillance Centre and the Food Standards Agency, where infections may have been acquired out of the County, overseas or from food produced outside of the UK.

The two teams work closely on such cases, being based in the same office. Where food businesses or commercial food supplies are implicated or involved, authorised food officers will take action as necessary, and these actions are recorded on Tascomi.
During 2021-22, 220 confirmed/suspected cases were notified for investigation.

In practice, notified cases are known to represent a relatively small proportion of the true cases of gastro-intestinal infection in the community, and have been estimated to be in the region of 10% of all cases. The reasons for the low level of reporting are numerous but include: cases not visiting their GPs (especially where symptoms are relatively mild and/or short lived); under reporting of suspected cases by GPs; and variation in faecal testing by GPs. The majority of cases of gastro-intestinal infection are, in any case, likely to be attributed to viral gastroenteritis, which causes relatively short-lived symptoms, is seldom tested for (other than to confirm it as a cause, where suspected in an outbreak) and furthermore is not notifiable unless suspected as being food borne. The true burden of gastro-intestinal infection on our communities is therefore much greater.

The following chart shows the breakdown of ‘notified’ cases of gastro-intestinal infection by type for the County during 2021-22:

Reported Cases of Food Poisoning and other Food related Infectious Disease across Pembrokeshire, by Type 2021 22

Reported Cases of Food Poisoning and other Food related Infectious Disease across Pembrokeshire, by Type 2021 22

  • Suspected food poisioning: 0
  • Shigella: 0
  • Other: 0
  • Listeria monocytogenes: 0
  • Entamoeba histolytica/dispar: 0
  • E-coli O157: 0
  • Hepatitis E: 2
  • Giardia: 2
  • Salmonella sp: 11
  • Crytosporidium: 17
  • Campylobacter: 188

In line with the national picture for England and Wales, the majority of ‘notified’ cases of gastrointestinal infection are caused by Campylobacter infection –i.e. 85% of all reported cases for Pembrokeshire during 2021-22.
Although Campylobacter is the commonest bacterial cause of infectious intestinal disease in England and Wales, its epidemiology remains poorly understood.

Undercooked meat (especially poultry) is often associated with illness, as is unpasteurised milk and untreated water. While most cases of Campylobacter infection are thought to be sporadic, and the routes of transmission remain unclear, a number of significant outbreaks have been identified across Wales over recent years, with the possibility of other outbreaks going undetected.

There were no outbreaks of food poisoning in 2021-22 which required the involvement of the Health and Safety/Communicable Disease Team.

Outbreaks involving food premises can be very time consuming, and may require input from some/all Team members over a number weeks, in carrying out the investigation and collating information. Senior management input at outbreak control meetings may also be required.
The following chart shows the trend in the number of reported cases each year over the 10 year period from 2012-13 to 2021-22 , for the top 5 laboratory confirmed causes of gastro-intestinal infections in the County.

Number of reported cases for the top 5 causes of GI infection 2012-13 to 2021-22

Campylobacter 140 188 209 179 162 177 183 302 150 188
Crytosporidium 18 14 8 15 17 20 30 75 35 17
Giardia 12 8 12 13 15 10 13 7 6 2
Shigella 1 0 1 1 3 4 0 1 1 0
Salmonella sp. 11 10 8 3 7 2 20 54 6 11


Having regard to the increase in Campylobacter across England and Wales, and the possibility of outbreaks going undetected, the national Communicable Disease Expert Panel undertook a project to develop a good practice standard for the investigation of Campylobacter, to promote a common approach to investigations and surveillance. This area of work, coupled with improved data capture and analysis through enhancements to the Tarian system, may result in the identification of further clusters/outbreaks and enable the role of animal products, other foods, water and non-foodborne exposures to be investigated further.

The Public Enquiry into the 2005 outbreak of E.coli O157 affecting schools across South East Wales was concluded in March 2008, with the final report (‘Pennington Report’) produced in March 2009. The Authority considered and adopted where appropriate recommendations made, having regard to any advice issued by the Welsh Assembly Government, FSAW, and the Welsh Food Safety and Communicable Disease Technical Panels that operate under the direction of the Directors of Public Protection Wales and Welsh Heads of Environmental Health. The template of the WLGA Responsibilities and Actions document was used to report actions and progress in reports to the Authority’s Corporate Management Team. The Authority’s response to the recommendations of the Pennington Report was audited by the Food Standards Agency Wales during 2013-14 (See 6.4.3 below).

3.7.2 Investigation and control of zoonoses

The Authority investigates notifications of a range of zoonotic diseases, in particular the loss of Officially Tuberculosis Free (OTF) status in cattle. Action is taken in accordance with the Council’s procedures based upon an All-Wales model document that provides for consistent responses and investigations.

During 2021-22, there were 52 notifications of restrictions on dairy herds as a result of loss of Officially Tuberculosis Free status were received, compared to 0 the previous year and 263 the year prior to that.
The low numbers reported during the Covid-19 pandemic period indicate a reduction in on-farm testing undertaken by Defra during that time.
The Authority is routinely notified of the loss of OTF status and is in turn takes steps to ensure that milk from reactor cattle does not enter the human food chain and that milk from the rest of the herd is subject to pasteurisation.
The Authority is also advised of the loss of OTF status in non-dairy cattle, though no action is required by the Team in respect of these notifications.
During 2017-18 to mitigate the impact of other increases in demand on the Food Team responsibility for initial contact of farmers in response to loss of Officially TB Free status of dairy herds was transferred to the Division’s Business Unit.

ID: 9920, revised 20/04/2023