REPORT. Cheshire, Cumbria, Greater Manchester, Lancashire, Merseyside, North Wales FLGs & HPA FWE Microbiology Network (Preston Laboratory)

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1 Cheshire, Cumbria, Greater Manchester, Lancashire, Merseyside, North Wales FLGs & HPA FWE Microbiology Network (Preston Laboratory) REPORT Microbiological Examination of Pre-packed Cooked Meat Sandwiches at the End of use by life from Outlets including Hospitals, with a Focus on Listeria monocytogenes K.Williamson, G.Allen, A J Fox HPA Food, Water and Environmental Microbiology Network (Preston Laboratory) Survey Number 8040 January 200

2 Microbiological examination of Pre-packed Cooked Meat Sandwiches at the end of use by life from outlets including hospitals, with a focus on Listeria monocytogenes K Williamson, G Allen, A Fox, HPA FWE Preston Laboratory Date of report: January 200 Survey Code No: 8040 Introduction Listeria monocytogenes is a foodborne pathogen which can cause severe infection especially in pregnant women and those who are immunocompromised. Consumption of contaminated food is the principle route of infection and the majority of cases are sporadic although common source outbreaks have been reported. Foods associated with transmission are predominantly ready to eat with extended (usually refrigerated) shelf life, capable of supporting the growth of Listeria. Since 2000 there has been a national rise in cases of listeriosis with a notable increase in the North West region. The reported increase has occurred almost exclusively in patients aged over 60 years. The rate of listeriosis has increased three-fold in the over 60s from the early 990s to present and doubled since 200. A recent LACORS/HPA survey of a selection of ready to eat foods () consumed by this age group indicated that sandwiches and cooked meats were the food types with the highest prevalence of L.monocytogenes. Local surveys (20400, 20403) have also highlighted sliced cooked meats as a source of L.monocytogenes and that the level after 48 hours refrigerated storage is of concern (60403). Pre-packed sandwiches are a popular meal type consumed by over 60s and served to vulnerable patients on hospital wards, hence the aim of this study was to examine pre-packed sandwiches with cooked meat as a main ingredient at the end of use by life. There have been several small outbreaks of listeriosis over the last 0 years associated with consumption of sandwiches in hospitals and more recently a cluster of 3 cases occurred in a Greater Manchester hospital with pre-packed sandwiches served on the wards being a possible source. EHO s expressed concern as to whether ward fridges used to store sandwiches are adequately temperature controlled. Hence it was decided to include pre-packed sandwiches sampled from hospital sources, particularly those intended for patients, and compare the microbiological quality with those from various other retail outlets. Materials and Methods Sample collection This survey was carried out as part of the North West Food Liaison Group sampling programme in co-ordination with the HPA FWE Preston Laboratory during September 2008 August Samples of any type of pre-packed cooked meat sandwich were collected by local authority sampling officers from hospital retail outlets, hospital kitchen and ward refrigerators and other retail or catering premises. Although additional sauce/relish (KW/KLM 43/09) Page of 3

3 ingredients were acceptable, a salad content was excluded from this study so as to increase the cooked meat content examined, reduce the incriminated ingredient option if Listeria detected, and allow interpretation of results by reference to category 4 of the PHLS ready to eat guidelines (2). Sandwiches were collected on or as near as possible to their use by date. The samples were placed into food grade plastic bags and transported to the laboratory at 0-8ºC. Information relating to premises, product, and whether the sandwich was collected from a refrigerated source was recorded onto a modified laboratory request form (Appendix ). Sample examination A total of 055 pre-packed cooked meat sandwiches were submitted by 42 North West local authorities as detailed in Appendix 2. All samples were refrigerated at 6ºC ± ºC on laboratory receipt until examination on the use by date. Sandwiches were aseptically removed from their packaging and a representative sample was examined for: aerobic colony count (ACC), enumeration of Enterobacteriaceae, E. coli, Staphylococcus aureus, Listeria spp and detection of Salmonella and Listeria spp. All tests were carried out using UKAS accredited food methods. Isolates of L.monocytogenes were referred to the Food Safety Microbiology Laboratory HPA Colindale for serotyping. Microbiology results Table - Microbiology results Hospital sandwiches (n=288) Detected Not detected <0, <20 0,20-< < < < < < <0 8 >0 8 ACC/g* Enterobacteriaceae/g E.coli/g S.aureus/g L.monocytogenes/g/in 25g Listeria spp (total)/g/in 25g Salmonella in 25g *ACC x 6 counts were VOID L.monocytogenes detected in 7/288 sandwiches (5.9%) Listeria spp other than L.monocytogenes detected in 68/288 (23.6%) Listeria spp (total) detected in 8/288 sandwiches (28.%) Table 2 - Microbiology results Non-Hospital sandwiches (n=767) Detected Not detected <0, <20 0,20-< < < < < < <0 8 >0 8 ACC/g* Enterobacteriaceae/g E.coli/g S.aureus/g L.monocytogenes/g/in 25g Listeria spp (total)/g/in 25g Salmonella in 25g *ACC x 0 counts were VOID L.monocytogenes detected in 43/767 sandwiches (5.6%) Listeria spp other than L.monocytogenes detected in 73/767 (9.5%) Listeria spp (total) detected in 09/767 sandwiches (4.2%) (KW/KLM 43/09) Page 2 of 3

4 Table 3 - Microbiology results All sandwiches (n=055) Detected Not detected <0, <20 0,20-< < < < < < <0 8 >0 8 ACC/g* Enterobacteriaceae/g E.coli/g S.aureus/g L.monocytogenes/g/in 25g Listeria spp (total)/g/in 25g Salmonella in 25g *ACC x 6 counts were VOID L.monocytogenes detected in 60/055 sandwiches (5.7%) Listeria spp other than L.monocytogenes detected in 4/055 (3.4%) Listeria spp (total) detected in 90/055 sandwiches (8.0%) Table 4 - Relevant parameters in category 4 of the PHLS microbiological guideline (2) Microbiological quality (cfu/g) unless stated Satisfactory Acceptable Unsatisfactory Unacceptable/potentially hazardous Aerobic colony count < < N/A Enterobacteriaceae <00 00-< N/A E. coli <20 20-<00 00 N/A Staphylococcus aureus <20 20-<00 00-< Listeria spp (total) <20 20-<00 >00 N/A Listeria <20 20-<00 N/A 00 monocytogenes Salmonella spp Not detected in 25g Detected in 25g N/A = Not applicable Listeria spp (total) includes L.monocytogenes and other Listeria species Table 5 - Microbiological quality using Category 4 of the PHLS microbiology guidelines (2) Satisfactory Acceptable Unsatisfactory Unacceptable/ potentially hazardous Hospital sandwiches (n=282) 47 (52%) 82 (29%) 53 (9%) 0 Non hospital sandwiches (n=757) 364 (48%) 227 (30%) 65 (22%) (<%) All sandwiches (n=039) 5 (49%) 309 (30%) 29 (2%) (<%) Table 6 - Listeria spp identification Identification Hospital sandwiches (n = 288) Number of isolates Non-hospital sandwiches (n = 767) All sandwiches (n = 055) L. monocytogenes 7 (5.9%) 43 (5.6%) 60 (5.7%) L. innocua 45 (5.6%) 33 (4.3%) 78 (7.4%) L. welshmeri 2 (4.2%) 35 (4.6%) 47 (4.4%) L. seeligeri (3.8%) 5 (0.6%) 6 (.5%) (KW/KLM 43/09) Page 3 of 3

5 Table 7 - Listeria monocytogenes isolates serotyping results hospital (n = 7), non hospital (n = 43) Number of isolates Serotype Hospital sandwiches Non-hospital sandwiches All sandwiches /2a 7 (00%) 3 (72%) 48 (80%) (23.2%) 0 (6.7%) /2b 0 (2.3%) (.7%) /2c 0 (2.3%) (.7%) Tables -3 summarise the microbiology results of 055 pre-packed sandwiches and differentiate results from hospital (288) and non-hospital (767) sources. Table 5 demonstrates that 2% of the total samples were of unsatisfactory quality based on category 4 of PHLS guidelines (2), and a similar prevalence of unsatisfactory results occurred from the hospital and non-hospital sources. The ACC was the main cause of unsatisfactory results with similar unsatisfactory levels found in hospital based sandwiches (45/282, 6%) and non-hospital based (46/757, 9%). Unsatisfactory levels of Enterobacteriaceace were the same (5.5%) and E. coli (0.3%, 0.5%) and Staphylococcus aureus (0%, 0.3%) were also similar in hospital and nonhospital based sandwiches respectively. No samples were found to be positive for the presence of Salmonella. The prevalence of L.monocytogenes was also similar in hospital (5.9%) and non-hospital (5.6%) sandwiches but Listeria spp other than L.monocytogenes was almost three times more frequently detected in hospital (68/288, 23.6%) than nonhospital (73/767, 9.5%). According to PHLS guidelines (2) hospital sandwiches only gave 2/288 (0.7%) unsatisfactory Listeria spp (other than L.monocytogenes) and no unsatisfactory/unacceptable L.monocytogenes results (>00cfu/g 00cfu/g). Non-hospital sandwiches gave the same /767 (0.3%) unsatisfactory results for both Listeria spp (other than L.monocytogenes) and L.monocytogenes. Table 6 shows that the prevalence of L. innocua in particular was significantly greater and the most common Listeria isolate in hospital sandwiches (5.6%) compared to non-hospital (4.3%), where the most common Listeria isolate was L.monocytogenes (5.6%) with other Listeria species also being detected. Table 7 demonstrates that all 7 L.monocytogenes isolates from hospital sandwiches were serotype /2a, compared with the majority of non-hospital L.monocytogenes isolates (72%) being serotype /2a with an additional 0/43 (23.2%) being serotype 4 and also a serotype of each /2b and /2c. Questionnaire results The questionnaire results were related to the microbiological quality with a focus also on the 4 Listeria spp (other than L.monocytogenes) and 60 L.monocytogenes detections. (KW/KLM 43/09) Page 4 of 3

6 Table 8 - Type of Premises hospital based sandwiches (n = 288) Café/ restaurant Ward * other than fridge Ward fridge Shop Main kitchen Vending machine No. of samples 45 (50.3%) 45 (5.6%) 36 (2.5%) 35 (2.%) 20 (6.9%) 7 (2.4%) Unsatisfactory microbiological quality 25 (7.2%) 2 (26.7%) 3 (8.3%) 8 (22.3%) 5 (25%) 0 L.monocytogenes detected 5 (3.4%) 0 7 (9.4%) 0 5 (25%) 0 L. spp other than L. monocytogenes 36 (24.8%) 6 (35.5%) 6 (6.7%) 6 (7.%) 2 (0%) 2 (28.6%) Listeria spp (total) n = 8 39 (26.8%) 6 (35.5%) 2 (33.3%) 6 (7.%) 6 (5.4%) 2 (28.6%) * includes WRVS trolleys, ward ambient Table 9 - Type of Premises non-hospital based sandwiches (n = 765) Café/ restaurant Bakery Petrol station Supermarket Convenience Store/Local brand grocer Newsagent Other small business * No. of samples 28 (3.7%) 73 (9.5%) 79 (23.4%) 56 (20.4%) 233 (30.5%) 29 (3.8%) 67 (8.7%) Unsatisfactory microbiological quality 7 (25%) 5 (6.8%) 4 (22.9%) 5 (9.6%) 62 (26.6%) 0 (34.5%) 26 (38.8%) L.monocytogenes detected 3 (0.7%) 3 (4.%) 9 (5.0%) 5 (3.2%) 0 (4.3%) 6 (20.7%) 7 (0.4%) L. spp other than L. monocytogenes 4 (4.2%) 5 (20.6%) 5 (8.4%) 8 (5.%) 2 (9.0%) 2 (6.9%) 8 (.9%) Listeria spp (total) n = 09 6 (2.4%) 7 (23.3%) 23 (2.8%) 2 (7.7%) 30 (2.9%) 6 (20.7%) 5 (22.4%) * Deli 4, off-licence 3, teaching establishment 7, sandwich bar 6, chemist 6, caterer 5, bingo hall 2, butchers 2, post office 2, vending machine 2, not stated 2, farm shop 2, department store, motorway service, producer, railway station, Table 0 - Type of cooked meat ingredient (n = 055) No. of samples 326 (30.%) Unsatisfactory microbiological quality L.monocytogenes detected L. spp other than L. monocytogenes Ham Beef Chicken Turkey Corned Beef 63 (9.3%) 4 (4.3%) 35 (0.7%) 9 (8.6%) 37 (40.7%) 2 (3.2%) 9 (9.9%) Listeria spp (total) n = (4.4%) 20 (22.0%) * Cheese, Gammon 2, Pastrami, Salmon 464 (44.0%) 72 (5.5%) 9 (4.%) 74 (5.9%) 88 (9.0%) 67 (6.3%) 27 (40.3%) 5 (7.5%) 4 (20.9%) 6 (23.9%) 30 (2.8%) (3.3%) 5 (6.7%) 3 (0.%) 8 (2.7%) Bacon Pork Lamb Sausage Tuna Other * (.0%) 3 (3.3%) 0 5 (42.3%) 0 3 (8.6%) 2 (8.2%) 2 (8.2%) (2.8%) 4 (.4%) (0.09%) (.0%) 0 2 (8.2%) (0.09%) (9.%) 0 2 (8.2%) (0.09%) 3 (27.3%) 4 (.3%) (7.%) 5 (0.5%) (20.0%) 0 0 (7.%) (7.%) 0 0 Table - Sample from refrigerated/non-refrigerated source (n = 048) Hospital based premises (n = 288) Non-hospital based premises (n = 760) Total premises (n = 048) * Refrigerated Ambient Refrigerated Ambient Refrigerated Ambient No. of samples 279 (96.9%) 9 (3.%) 75 (98.8%) 9 (.2%) 030 (98.3%) 8 (.7%) Unsatisfactory microbiological quality 5 (8.3%) 2 (22.2%) 60 (2.3%) 4 (44.4%) 2. (20.5%) 6 (33.3%) L.monocytogenes detected 4 (5.0%) 2 (22.2%) 43 (5.8%) 0 57 (5.5%) 3 (6.7%) L. spp other than L. monocytogenes 67 (24.0%) (.%) 70 (9.3%) 2 (22.2%) 27 (2.3%) 3 (6.7%) L. spp (total) n = (28.0%) 2 (22.2%) 06 (4.%) 2 (22.2%) 84 (7.9%) 5 (27.8%) * 7 not stated (KW/KLM 43/09) Page 5 of 3

7 Table 8 indicates that the number of unsatisfactory microbiological quality results and the prevalence of Listeria spp was highest from non-refrigerated sources on the wards such as from WRVS trolleys. However a fifth of samples from ward refrigerators and a quarter from main hospital kitchens (5 fridge, 5 ambient) had L.monocytogenes present. Table 9 indicates small business premises and newsagents supplied the highest proportion of unsatisfactory microbiology samples with L.monocytogenes being detected in a fifth of newsagent samples. Listeria spp other than L.monocytogenes was most prevalent in sandwiches from bakeries. Table 0 indicates that beef, turkey and pork were the meat ingredients producing the most unsatisfactory results with beef (3.2%) and corned beef (6.7%) producing the highest proportion of L.monocytogenes detections. Turkey (20.9%) and chicken (5.9%) sandwiches produced the highest proportion of Listeria spp other than L.monocytogenes. Table compares the effect of refrigeration on microbiology results although ambient source samples were low (8). The proportion of unsatisfactory microbiological quality results from ambient sources was higher (33%) than refrigerated (20%). Unsatisfactory results and presence of L.monocytogenes were at a similar level from hospital and nonhospital refrigerated sources. Both L.monocytogenes detections from ambient sources were hospital based. The proportion of Listeria spp other than L.monocytogenes was almost three times higher in hospital based refrigerated samples than non-hospital refrigerated samples. Overall the prevalence of total Listeria spp in hospital based refrigerated samples (28%) was twice the prevalence as from non-hospital based premises refrigerators (4%). Figure. Seasonality related to unsatisfactory microbiological quality and Listeria monocytogenes detection Seasonality related to microbiological quality of sandwiches 35% 30% 25% % samples 20% 5% % L.mono detected in 25g % ACC >0^7/g % Enteros >0^4/g % Cat 4 RTEF Unsatisfactory 0% 5% 0% Sep-08 Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jun-09 Jul-09 Aug-09 Month sampled (KW/KLM 43/09) Page 6 of 3

8 Figure demonstrates the seasonality trend with increased unsatisfactory results in the warmer May August months peaking in May with the highest number of failures due to ACC, and the highest proportion of samples with Listeria spp (total) and L.monocytogenes. Although the ACC is a good hygiene indicator related to seasonality temperatures, there is no evidence of it being a good indicator for presence of Listeria spp. Discussion This study details the microbiological quality and presence of L.monocytogenes and other Listeria spp in pre-packed sandwiches from a wide range of retail premises and in particular from hospital based outlets in the North West. Although listeriosis is rare in the UK there have been four outbreaks associated with sandwiches purchased or provided in hospitals (3). Food hygiene in hospitals is especially important because patients are likely to have less resistance to infection from contaminated food. It is recognised that cafes and shops in hospitals could supply pre-packed sandwiches to consumers including vulnerable patients or outpatients, as well as hospital and ward kitchens, hence these sources are included in this study. L.monocytogenes is widely prevalent in the environment, resistant to diverse environmental conditions and able to grow at refrigeration temperatures. Concern has therefore arisen over the safe production and storage of sandwiches within hospitals due to the increased susceptibility of the potential consumers. Sandwiches with a main ingredient of cooked meat were selected for this study because previous local and national surveys of cooked meat have demonstrated a L.monocytogenes prevalence of 5% - 7.3% (Local: 20403, 20400, 50402, 60403) and the LACORS/HPA 2003 survey (4). They are also a typical type of sandwich having a high potential for contamination from Listeria due to extensive handling during preparation of the filling, sandwich assembly and packing or from cross contamination from the environment. In order to achieve a satisfactory level of microbiological quality, good hygiene and food safety practices are essential from preparation to retail/provision/consumption. Pre-packed sandwiches were examined at the end of their use by life in this study in order to assess that high quality ingredients and good temperature control in particular have been used so as to attain the specified shelf life with good microbiology results. Pre-packed sandwiches are a high risk food product because they are a ready to eat food with the capability of supporting bacterial growth under favourable conditions, including L.monocytogenes at refrigeration temperatures. The number of listeriosis cases has increased significantly since 2000, predominantly among people over 60. The FSA have recently published a report (5) indicating that people over the age of 60 are more likely than young people to take risks with use by dates. Additionally it was highlighted that more than half (6%) of this age group do not check their refrigerator temperatures. It is therefore possible that sandwiches reported as satisfactory microbiological quality according to PHLS Ready-to-eat Food Guidelines (2) even when L.monocytogenes is present at <20cfu/g, may be eaten by the elderly beyond the use by date and therefore increase the risk of listeriosis due to further multiplication. For these reasons the microbiological quality of pre-packed cooked meat sandwiches from (KW/KLM 43/09) Page 7 of 3

9 a wide range of retail outlets which may well be consumed by the elderly were assessed as well as from hospitals. In this study although the microbiological quality and L.monocytogenes detections in prepacked sandwiches from hospital and non-hospital sources are similar (Tables 2-5) it must be highlighted that Listeria spp other than L.monocytogenes were almost three times as prevalent in hospital based sandwiches. Listeria spp other than L.monocytogenes are rarely associated with human infection but act as indicator organisms in food microbiology. If Listeria spp are isolated then conditions would have been suitable for L.monocytogenes. Although only 0.4% of samples examined in this study were of unsatisfactory quality due to Listeria counts of >00/g it is of concern that 8% were contaminated with low numbers and that 28% of hospital based sandwiches were contaminated with low levels of Listeria spp (total) and 6% were L.monocytogenes. Levels of L.monocytogenes below 00cfu/g are usually not considered significant for human disease except in vulnerable population groups including the elderly. Current EC microbiological criteria indicate that levels of <00cfu/g in ready-to-eat foods within shelf life are legally satisfactory (6). Similarly the PHLS ready-to-eat Guidelines (Table 4) consider a L.monocytogenes count of up to 00cfu/g as acceptable. In this study 36/820 (4.4%) of the satisfactory/acceptable results included the presence of L.monocytogenes. Since 985 in the USA a zero tolerance policy has operated for L.monocytogenes in readyto-eat foods (7). This policy has recently been limited to those foods able to support its growth. The development of microbiological criteria for L.monocytogenes in ready-to-eat foods is currently being reviewed at international level by the Codex Committee in Food Hygiene (8). As part of this, the European Food Safety Authority is also reviewing assessment criteria for this pathogen. The British Sandwich Association (BSA) currently recommends a target level of <0cfu/g of L.monocytogenes in sandwiches at production. However, Article 4 of Regulation (EC) No. 78/2002 states Food shall not be placed on the market if it is unsafe. Food shall be deemed to be unsafe if it is injurious to health or unfit for consumption. This requires taking into full consideration all microbiological parameters and the intended consumer when setting shelf life. Hence consideration should be given to shorter use by life or consumption on day of preparation when sandwiches are intended for vulnerable groups such as hospital patients. The recent LACORS/HPA survey of a wide selection of sandwich types from hospitals and residential care homes reported the presence of Listeria spp in 7.6% of samples and L.monocytogenes in 2.7% of samples and supported the view that it may be more appropriate for manufacturers supplying sandwiches to hospitals to operate a zero tolerance level for L.monocytogenes. In this study it is of concern that on targeting cooked meat sandwiches there were almost four times as many detections of Listeria spp (8%) and twice as many L.monocytogenes detections (5.7%) than in the LACORS study. Both studies also indicated turkey and beef as the ingredients causing a high proportion of unsatisfactory results and Listeria spp detections. The high proportion of L.monocytogenes in corned beef sandwiches (6.7%) in this study was caused by a cluster of 3/5 L.monocytogenes isolated from the same supplier sandwiches from the same location during one week. The predominant serotype of L.monocytogenes identified in this study was /2a (72%), and all of the 7 L.monocytogenes isolates from hospital based sandwiches were serotype /2a. This study has highlighted that 5 of the 7 sandwiches with L.monocytogenes serotype /2a were provided by the same manufacturer X from (KW/KLM 43/09) Page 8 of 3

10 September 2008 August 2009 to 7 different hospitals. A fifth of sandwiches from ward fridges 7/36 had L.monocytogenes serotype /2a present (3 ham, 3 corned beef, turkey from 3 hospitals) and all were supplied by manufacturer X. A quarter of the sandwiches from main hospital kitchens (5/20) had L.monocytogenes serotype /2a present (beef (2), turkey (), ham (), lamb() from 2 hospitals on two separate occasions) and were supplied by manufacturer X. None of the 3 L.monocytogenes serotype /2a isolated from non-hospital based sandwiches were supplied by manufacturer X indicating that the main customer base of manufacturer X may be hospitals. It is also of concern that the prevalence of Listeria spp other than L.monocytogenes in hospital based sandwiches (23.6%) was almost three times the prevalence in non-hospital sandwiches (9.5%). However the type of sandwich was varied as was the sampling source, and the manufacturer. The NHS has a national framework agreement for the supply of sandwiches which also covers the Womens Royal Voluntary Service (WRVS). Suppliers are only awarded a framework agreement if they have achieved approval against the NHS code of practice for food safety. All foods consumed by hospital patients should be free from potential pathogens, including L.monocytogenes, and those responsible for procuring sandwiches for hospitals should ensure the safety of vulnerable patients. In particular food safety procedures for hospitals should include both main hospital and ward kitchens and ensure good temperature control (<5ºC) of their refrigerators and ensure sandwiches are consumed as close as possible to their production date. Local authorities are therefore encouraged to continue routine sampling from these important locations. All ten isolates of L.monocytogenes serotype 4 were from non-hospital small businesses including 4 petrol stations and 3 newsagents. Seven of these 0 sandwiches were provided by the same manufacturer Y. These isolates will be further subtyped so as to be of use for the epidemiology of recent clusters of cases due to this serotype. The types of sandwiches included beef (4), chicken (3), pork (2), turkey () and were supplied intermittently during the year of the survey. Given that the elderly population will rise significantly during the next decades and that the elderly population frequently consume pre-packed cooked meat sandwiches it is essential that sandwich manufacturers as good practice should take into account the intended consumer and aim to ensure L.monocytogenes is absent from their product wherever possible, and consider recommending consumption on the day of preparation. Conclusions It is of concern that based on Category 4 of PHLS Guidelines (3) 9% of hospital sandwiches and 22% of non-hospital sandwiches were of unsatisfactory microbiological quality, predominantly caused by high ACCs. It is of great concern that Listeria spp (28%, 4%) and L.monocytogenes (5.9%, 5.6%) were detected in samples from hospitals, and non-hospital premises respectively. (KW/KLM 43/09) Page 9 of 3

11 All L.monocytogenes isolates from hospital based sandwiches were serotype /2a and the majority supplied by the same manufacturer X. Almost a quarter of the L.monocytogenes isolates from non-hospital premises were serotype 4 and the majority supplied by the manufacturer Y. Almost a fifth of sandwiches from hospital ward fridges and a quarter of sandwiches from hospital main kitchens contained low levels of L.monocytogenes. These fridges should be regularly monitored and maintained at 0-5ºC. L.monocytogenes was detected in non-hospital based sandwiches more frequently from small businesses including newsagents shops and petrol stations. Cooked beef and turkey were the ingredients producing the highest number of unsatisfactory results and Listeria spp detections. Listeria spp was twice as prevalent in hospital based refrigerated samples than nonhospital premises refrigerated samples. All isolates of L.monocytogenes from food samples should be subtyped as well as serotyping in order to improve our understanding of the epidemiology of listeriosis. The majority of unsatisfactory results predominantly due to high ACC s occurred between May to August but the ACC did not act as a reliable indicator for the presence of L.monocytogenes. In this survey 36/820 (4.4%) of samples were of satisfactory microbiological quality according to PHLS Guidelines (2) but had L.monocytogenes present. When L.monocytogenes is detected in a pre-packed sandwich, food examiners and the sending authority should consider the susceptibility of potential vulnerable groups and the remaining shelf life before interpreting the result. Sandwich manufacturers should take into account the intended consumer when setting target acceptance levels for L.monocytogenes. Consideration needs to be given to the elderly population as well as hospital patients who may consume their product, and the need to aim for a L.monocytogenes zero tolerance at production. Consideration should also be given to shorter use by life or recommend consumption on the day of preparation when sandwiches are intended for vulnerable groups. Future work Continue routine sampling of cooked meat sandwiches from hospital kitchens and wards. Repeat of study (60400 June 2006) of environmental samples from cooked meat processing premises for Listeria spp. Also consider inclusion of cooked meat sample, and premises supplying cooked meat to hospitals, or to sandwich manufacturers supplying hospitals. (KW/KLM 43/09) Page 0 of 3

12 References () LACORS/HPA Co-ordinated Food Liaison Group Study Report: Assessment of the microbiological safety of selected retail ready-to-eat foods with a focus on Listeria monocytogenes July (2) Guidelines for microbiological quality of some ready-to-eat foods sampled at point of sale, PHLS, ACFDP working group, Communicable Disease and Public Health, Sept 2000; Vol 3: (3) LACORS/HPA Report on the microbiological examination of sandwiches from hospitals and residential/care homes with a focus on L.monocytogenes. (4) Microbiological safety of retail vacuum-packed and modified atmosphere packed cooked meats. S K Sagoo, C Little, G Allen, K Williamson and K Grant. J. Ed. Protect. Vol 70, No.4, 2007 pge (5) FSA Report Public attitudes to Food Issues further analysis on those aged 65 and over, June 2009, (6) European Commission Commission Regulation (EC) No. 2073/2005 on microbiological criteria for foodstuffs. Off. J. Eur. Union 2005: L338: -26. (7) Shank FR, Elliot EL et al (996), U S position on Listeria monocytogenes in foods. Food Control, 7 (4/5), (8) Codex Committee on Food Hygiene. Draft guidelines on application of general principles of food hygiene to the control of L.monocytogenes in ready-to-eat foods. (KW/KLM 43/09) Page of 3

13 Appendix Request Form (KW/KLM 43/09) Page 2 of 3

14 Appendix 2 - Participants Authority Number of samples examined Allerdale 2 Carlisle 9 Copeland 0 Eden 4 CUMBRIA TOTAL 45 Chester 23 Congleton 3 Crewe & Nantwich 29 Ellesmere Port & Neston 0 Halton 5 Macclesfield 6 Vale Royal 20 Warrington 34 CHESHIRE 50 Bolton 46 Bury 37 Manchester 3 Oldham 35 Rochdale 44 Salford 42 Stockport 42 Tameside 29 Trafford 27 Wigan 47 GREATER MANCHESTER TOTAL 362 Barrow 4 Blackburn 9 Blackpool 56 Burnley 7 Chorley 5 Fylde 63 Hyndburn 5 Lancaster 26 Pendle 8 Preston 0 Ribble Valley 3 Rossendale 9 South Lakes 3 South Ribble 7 West Lancs 2 Wyre 6 LANCASHIRE 337 Knowsley 6 Liverpool 56 St Helens 28 Sefton 5 Wirral 7 MERSEYSIDE TOTAL 58 Flintshire 3 Wrexham 0 NORTH WALES TOTAL 3 Total for Cumbria, Cheshire, Greater Manchester, Lancashire, Merseyside, North Wales 055 (KW/KLM 43/09) Page 3 of 3