1 Recent International Efforts to Improve Bivalve Molluscan Shellfish Safety
11
FAO/WHO convened an Expert Consultation in Ottawa in October 2011, the
results of which were presented to the 43rd Session of CCFH. The Expert Meeting
noted that in parts of the world where harvesting of bivalve molluscs for direct
human consumption is controlled through sanitary surveys using fecal coliforms
or Escherichia coli, 0.5–2 % samples could be positive for Salmonella, but
epidemiological evidence from these regions indicate that there have been very few
outbreaks (in the order of one every few years) and usually involving relatively
small number (<10) of consumers. Thus the Expert Meeting concluded that bivalve
molluscs harvested from areas controlled through sanitary surveys do not cause
frequent outbreaks of salmonellosis. The Expert Meeting used two approaches
to address the question on the usefulness of the criterion. The first, based on
available data, looked at the incremental value of having a Salmonella test over
using the fecal indicator (fecal coliform/E. coli) test. This indicates that performing
a Salmonella test in addition to the E. coli test would increase the number of
unacceptable lots detected from 9.0 to 9.5 %. The second theoretical approach was
based on the performance of the following sampling plan n D 5, c D 0, m D 0/25 g.
This sampling plan cannot reliably detect contamination level of less than 2–5
cells of Salmonella/200 g serving (which translates to an estimated risk of 1 in
200 servings). Thus the assurance provided is that the risk is less than 1 in 200
and epidemiological data indicates that it is much lower than that. Therefore, the
conclusion of the Expert Meeting was that the Salmonella criterion provides little
or no additional protection than that achieved by current risk management strategy
using fecal indicators.
Taking into consideration this information, the 43rd Session of CCFH agreed to
recommend to the Committee on Fish and Fishery Products (CCFFP) to remove
the criterion for Salmonella (Section I-6.5) from the Standard for Live and Raw
Bivalve Molluscs (CODEX STAN 292–2008) and to include in the Code of Practice
for Fish and Fishery Products, Section 7.2.2.2, the following: “When appropriate,
taking into account the epidemiological situation as indicated by the results of
environmental monitoring and/or other surveillance, the competent authority may
decide to implement a criterion for Salmonella.”
Conclusions
Bivalve molluscs constitute an important segment of the seafood industry and
production by aquaculture has been growing at a significant pace. Live and raw
bivalve molluscs are a high value commodity and while developing standards
and codes of practices for this commodity, there were a number of scientific
issues such as biotoxins, pathogenic Vibrio spp. and Salmonella that came up
for advice by FAO/WHO. The risk assessment performed by FAO/WHO has
led to the development of the Codex Guidelines on the application of general
principles of food hygiene to the control of pathogenic Vibrio species in seafood.
The development of risk management tool for V. parahaemolyticus, that has wide
geographical application, requires more data from different regions.
11
FAO/WHO convened an Expert Consultation in Ottawa in October 2011, the
results of which were presented to the 43rd Session of CCFH. The Expert Meeting
noted that in parts of the world where harvesting of bivalve molluscs for direct
human consumption is controlled through sanitary surveys using fecal coliforms
or Escherichia coli, 0.5–2 % samples could be positive for Salmonella, but
epidemiological evidence from these regions indicate that there have been very few
outbreaks (in the order of one every few years) and usually involving relatively
small number (<10) of consumers. Thus the Expert Meeting concluded that bivalve
molluscs harvested from areas controlled through sanitary surveys do not cause
frequent outbreaks of salmonellosis. The Expert Meeting used two approaches
to address the question on the usefulness of the criterion. The first, based on
available data, looked at the incremental value of having a Salmonella test over
using the fecal indicator (fecal coliform/E. coli) test. This indicates that performing
a Salmonella test in addition to the E. coli test would increase the number of
unacceptable lots detected from 9.0 to 9.5 %. The second theoretical approach was
based on the performance of the following sampling plan n D 5, c D 0, m D 0/25 g.
This sampling plan cannot reliably detect contamination level of less than 2–5
cells of Salmonella/200 g serving (which translates to an estimated risk of 1 in
200 servings). Thus the assurance provided is that the risk is less than 1 in 200
and epidemiological data indicates that it is much lower than that. Therefore, the
conclusion of the Expert Meeting was that the Salmonella criterion provides little
or no additional protection than that achieved by current risk management strategy
using fecal indicators.
Taking into consideration this information, the 43rd Session of CCFH agreed to
recommend to the Committee on Fish and Fishery Products (CCFFP) to remove
the criterion for Salmonella (Section I-6.5) from the Standard for Live and Raw
Bivalve Molluscs (CODEX STAN 292–2008) and to include in the Code of Practice
for Fish and Fishery Products, Section 7.2.2.2, the following: “When appropriate,
taking into account the epidemiological situation as indicated by the results of
environmental monitoring and/or other surveillance, the competent authority may
decide to implement a criterion for Salmonella.”
Conclusions
Bivalve molluscs constitute an important segment of the seafood industry and
production by aquaculture has been growing at a significant pace. Live and raw
bivalve molluscs are a high value commodity and while developing standards
and codes of practices for this commodity, there were a number of scientific
issues such as biotoxins, pathogenic Vibrio spp. and Salmonella that came up
for advice by FAO/WHO. The risk assessment performed by FAO/WHO has
led to the development of the Codex Guidelines on the application of general
principles of food hygiene to the control of pathogenic Vibrio species in seafood.
The development of risk management tool for V. parahaemolyticus, that has wide
geographical application, requires more data from different regions.