Vibrio

 Some Vibrio  parahaemolyticus (Vp) protocols:

  • Once an area is closed by testing over 100 (there are only six vibrio indicator testing sites), it is up to the individual farmer to take product that is due to be harvested to a lab for testing (north island lab).  The product needs to come in at a count less than one hundred.  The individual lease samples can be done as often as the grower wants until they finally get a count of less than one hundred, at which time it is then safe to harvest.
  • If the product is from a deep water site and is to be shucked only, then it is ok to harvest with the higher count, since the shucked containers have warnings on them.
  • In order to discontinue the vibrio protocal, the indicator testing sites need to have two consecutive less than 100 tests.

Oyster Shellstock
As described in Section 2.2 of the 2012 Industry Notice:

  • as soon as the CFIA environmental indicator station for an area showsVp levels greater than 100 MPN/g, oyster shellstock from the affected area may only be harvested under a monitoring system  that shows the specific harvest site is safe (see below regarding shellstock destined for shucking)
  • an acceptable example of a monitoring system is to conduct weekly monitoring of Vp levels at specific harvest sites and only harvest from sites where Vp levels do not exceed 100 MPN/g.
  • industry monitoring must begin as soon as the CFIA environmental indicator station for an area shows Vp levels greater than 100 MPN/g.
  • industry monitoring may be discontinued when:  1) the CFIA indicator site for the area shows two consecutive weeks with Vp levels not exceeding 100 MPN/g; and 2) the current industry monitoring results do not exceed 100 MPN/g.
  • an  area is not currently “closed” by a DFO Prohibition Order (although there may be some situations where it could be).  As long as the monitoring system in place has a representative test result indicating the specific harvest site is currently <100 MPN/g Vp then harvest may occur.  If there is a harvest site result >100MPN/g Vp, the harvester has to stop harvest and keep testing until the current result is <100 MPN/g Vp, at which time harvest of oyster shellstock may again proceed.

Please remember that the sample must be representative of the type of harvest taking place (for example, a beach culture sample when beach culture oysters are being harvested, plus sampled at a time/tide level (etc.) when the oysters would be harvested).

Oyster Shellstock for Shucking
For oyster shellstock that is to be used for shucking, section 2.3 of the 2012 Industry Notice states that:

  • oysters for shucking do not require Vp harvest site monitoring of Vp levels by industry, but containers are required to have a cooking advisory during the Vp season.
  • each individual container of shucked oysters must be labelled to indicate that the product should be thoroughly cooked prior to consumption to a minimum internal temperature of 60°C for 5 minutes.
  • Time and temperature controls  are not mandatory, but they are highly recommended (it is best to prevent Vp growth in the first place!)

 

CFIA’s 2012 B.C. Oyster Vibrio parahaemolyticus (Vp) Control Requirements Document here.