Dear Richard:
Very difficult to provide useful comments without information on the specific Vibrio; but I think that you are right regarding Vibrio parahaemolyticus (Vp) and Vibrio vulnificus.
Regarding Vp a “Discussion paper on Risk Management Strategies for Vibrio spp in seafood” prepared for the Codex Committee on Food Hygiene can be downloaded from:
ftp://ftp.fao.org/codex/ccfh35/fh0305ce.pdf
This document contains data from different sources on Vibrio parahaemolyticus.
Probably the most relevant formal document available on the subject is: “Quantitative Risk Assessment of the Public Health Impact of Pathogenic Vibrio parahaemolyticus (Vp) in raw oysters” http://www.cfsan.fda.gov/~dms/vpra-toc.html
FDA has prepared two successive versions of this quantitative risk assessment (2001 and 2004). The Interpretative Summary is an excellent lecture that could be read together with a PPT presentation (PDF) on the 2004 assessment in:
http://www.state.nj.us/dep/bmw/ISS_NESSA/Depaola.pdf
I think that the documents above condensate the best science that is possible to find today on Vp. In the case of the FDA the model has been validated (level of Vp in oysters before consumption), and this alone marks a large conceptual difference with other similar assessments.
Whereas there could be differences regarding scallops (with reference to oysters), the main aspects should be there.
The main problem with Vp is that it is part of the normal flora of sea water, therefore if sea water temperature rises (e.g. the threshold temperature usually mentioned is 15 °C); or if bivalves are exposed at high temperatures (e.g. after harvesting or to high air temperatures or between low and high tides) Vp would grow. I do not want to appear unfriendly, but you have Vp in UK (see for instance Ref. 1).
My particular feeling, without data at the hand (and this is a constant problem of many of the questions that arrive to the site) is that the possible risk should be very low if:
(i) scallops have been handled and kept at low temperatures since harvesting;
(ii) it is really a chilled product (and kept and transported like that);
(iii) product is going to be cooked before eating.
You and your client know about (i) and in part about (ii) (but you may not know about some T abuse during transport, why the Italian Vets took samples for analysis?). Regarding (iii) no matter what you write in your HACCP plan, the reality is what the people is going to do with the seafood you sent. For instance maybe it finished in a sushi bar; some people fell ill the policy/ vets took samples, etc.
Even if the product is really cooked, risk assessment models generally allow for some % of insufficient cooking, and as a matter of fact when checking systematically cooked bivalves may appear a % that were not cooked enough (according with Ref. 1 this percentage was 4 % in UK, with a portion of that, 0.4 % of the total, due to Vp). It shall be said that other research reports (e.g. Ireland, Italy) have reported 0 % Vp in cooked commercial crustaceans and shellfish. However, no risk assessor would assume 100 % reduction always; more likely, if a risk assessment is conducted for the European Union, the reduction in Vp, could be, for instance a distribution between 99.6 and 100 % (it would be necessary to search for results from other EC countries).
Whereas it is true that there is no provision on Vp in Regulation (EC) No 273/ 2005, for the study conducted under Recommendation 2003/10/EC (taken as reference in Ref. 1) the microbiological criteria utilized was:
Total Vp count (batch samples. Each batch comprised of 5 samples)
Satisfactory: All samples < 30 cfu/g
Acceptable: All samples <=10E(02) and no more than 2 samples in the range 30 - <=10E(02) cfu/g
Unsatisfactory: Any sample >10E(02) or 3 or more samples in the range 30 - <=10E(02)
(Ref.: http://www.fsai.ie/surveillance/food_safety/microbiological/cooked_crustraceans_molluscan.pdf)
Warning: Please notice the criterion above mentioned was utilized only as guideline for the exercise proposed by Recommendation 2003/10/EC, and it is not the formal EC requirement on Vp.
Nevertheless, if your client want to utilize some criteria for verification purposes, within a proper HACCP plan, not for control batch by batch, he/she could eventually utilize (for the EC) the above microbiological criteria. Certainly the criterion is not absence of Vp. From here is that is not rational to reject a shipment based only on Vibrio spp (+).
With a proper HACCP plan and GMP/GHP (always low T) and verification according microbiological criteria the EC wrote in some document (even if it is not a regulation) you should be within the EC HACCP framework.
To have things in more detail, then a quantitative Risk Assessment would be necessary and probably some further applied research to complete some of the necessary data. Risk assessments are today still research realm, but with time they will be a standard stuff for food technologists, the way to analyze properly “what if…” scenarios (2020?)
Finally I agree that Fish Inspectors should be in occasions more explicit.
Kind regards.
Hector M. Lupin
Ref. (1)
Microbiological study of cooked crustaceans and molluscan shellfish from UK production and retail establishments. Satnam K. Sagoo; Christine L. Little; Melody Greenwood . International Journal of Environmental Health Research, Volume 17, Issue 3 June 2007 , pages 219 – 230.
“Abstract
A study of cooked crustaceans and molluscan shellfish from retail and production premises was undertaken in the UK during 2003 to determine the microbiological safety of these products. According to criteria in European Commission Recommendation 2003/10/EC, 96% of 682 batches were of satisfactory/acceptable microbiological status while 4% of batches were unsatisfactory due to the presence of high levels of Escherichia coli (3.3%; 102 to 106 cfu g-1), Vibrio parahaemolyticus (0.4%; 102 to 106 cfu g-1), and Staphylococcus aureus (0.3%; > 103 cfu g-1). Salmonella spp. were not detected in any of the batches examined. However, a higher proportion of cooked crustacean and molluscan shellfish would be considered to be unsatisfactory using the process hygiene criteria for E. coli according to previous (5%; 93/51/EEC) and new (7%; (EC) No 2073/2005) European legislation. Over twice as many molluscan shellfish batches were of unsatisfactory microbiological status (5%) compared to that of crustacean batches (2%). Cook
ed molluscan shellfish and crustaceans were more likely to be microbiologically contaminated if: they were unfrozen; a hazard analysis system was not in place; the manager had received no food hygiene training. Shellfish and crustaceans are exposed to a range of conditions during harvesting, production and distribution, and this may increase the potential for microbial contamination, highlighting the need for applying good hygiene practices throughout the food chain to prevent contamination and/or bacterial growth.”
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>From : owner-seafood@ucdavis.edu
To : "seafood" seafood@ucdavis.edu
Cc :
Date : Thu, 6 Dec 2007 19:41:54 -0000
Subject : Vibrio spp in scallops
> I am seeking information on Vibrio for risk assessment purposes. My clients recently had Vibrio spp identified in an export consignment of chilled scallops (Pecten maximus) going from the UK to Italy. We can not get information about the cfu's and the Italian vets will not identify the species.
>
> Our HACCP identifies Vibrio as being a low level risk as the product is to be cooked before eating, large numbers are needed for infection, the organisms themselves are not common in UK waters (normally needs 15C). I have references from FAO and other sources.
>
> What I would like to hear of are the experiences of others with this organism in a low risk food. Our problem is that the Italians, naturally, want confidence that Vibrio is not a significant hazard whilst my clients cannot test very batch prior to export.
>
> Vibrio has not previously been considered a significant risk in UK raw fish. Furthermore EU Reg 2073/2005 has no limits for Vibrio, but comments that:
>
> 'Currently available scientific data do not support setting specific criteria for pathogenic V. vulnificus and parahaemolyticus in seafood'
> and recommend that:
>
> 'There is a need for development of reliable methods for other microbial hazards too, e.g. Vibrio parahaemolyticus.'
>
> Are there any other standards that are applied to Vibrio in other parts of the world?
>
> Many thanks
>
>
>
> Richard Chivers
>
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