Oyster Upheaveal

New Requirement of Pre-Export Norovirus Testing For Frozen Oysters Exported To Singapore

Due to an increase of food poisioning outbreaks associated with the consumption of frozen oyster because of norovirus contamination, AVA will impose pre-export testing for norovirus in every consignment of frozen oyster, whether in half-shell, whole-shell or meat exported to Singapore with effect from 1 June 2007. This will therefore require the competent relevant government authority of the exporting countries to vertify in the health certificate that the consignment of frozen oysters has been tested and found free of norovirus. This certification will be in addition to the existing certification requirements, which will be read as follow:

a) the oyster were harvested from approved waters and processed in an approved establishment/plant in a sanitary and hygienic manner;

b) the oysters have not been treated with chemical preservatives and additives injurious to health;

c) the oyster have been tested and found free of norovirus;

d) the product is fit for human consumption.

Please contact Mr Thomas Lee at tel 63257102 or me ( Mr Koh Cheng Liat ) at 63257879 if you need further clarifications.

Contact for fuck. I called so many times and no one picked up the phone.

Agri-Food & Veterinary Authory of Singapore ( AVA ) is becoming more of a pest nowadays. My dad's business is seriously affected by this delayed-and-over-reacted testing for norovirus these days. Why do i say "delayed"? As a science student, i've did a mini research on this matter. There is no recent food poisioning outbreak associated with the consumption of frozen oysters because of norovirus contamination. The outbreak occurred in 04 Nov 2003, 4 years ago, where half-shelled RAW oysters served in hotels, clubs and restaurents were suspected. The specific shipment import from Shandong, China was problematic and the remaining 21 carton was recalled. No further outbreak was report since then, and it took AVA 4 years before they started do anything.

Finally when AVA implemented a norovirus testing, ALL oysters in Singapore did not meet the requirement, including our supplier Pan Ocean Singapore Pte Ltd, which has rumoured a future increase in oyster price to gain a hefty profit from the retailers. Anyway, all the consignment was burned and destroyed. Called two other suppliers and they replied the same thing.

From the Journal of Infection (2005)51, 413-418 Oyster-associated outbreaks of Norovirus gastroenteritis in Singapore, electron microscope and real-time reverse transcription PCR on ABI PRISM 7700 Sequence Detector was used to examine the presence of Norovirus.

Picture taken from Journal of Infection (2005)51, 413-418 via NTU database.
This is the actual figure in the journal itself. Figure 4.
What can u see from this picture? Can you see the presence of norovirus particle round, granular with a diameter of ~35nm, a ragged edge and an morphous surface appearance? I don't know what is it that "dot" myself, but i can conclude that this EM has low sensitivity and has a rather low resolution. In the journal, they used real-time reverse transcription PCR on ABI PRISM 7700 Sequence Detector. So? How big is your sample size? Do you know you have limited stool samples being tested, which may result in statistical error? Did you know that norovirus can be inactivated at temperature higher than 60 degrees? Try touching the frying pan to see if its more than 60 degrees. It is fair to ban all oyster now when it is the hotels and restaurants that is serving the raw contaminated oysters 4 years ago? Did you consider the possibility of false-positive results? Although there is no routine test for norovirus ( or viral contamination ) in the service laboratory previously, isn't it too harsh to burn all the consignment now that u've started testing? Even if all the while norovirus was present, Singaporean for the past few years have been eating and they are fine. Now that a few weak westerners ate the raw oyster had diarrhoea, it is fair to the general public, where no previous outbreak associated with comsumption of raw oyster has been reported? Problematic. High carrier frequency for cystic fibrosis already still want to eat raw oyster and self-destruct.

Anyway this matter will not rest. Initially i thought the police force was useless enough, now AVA is giving more trouble. Now none of the oyster consignment from all the supplier passed your test. Everything is burned. Thanks man. SAF is fucked up too. Great. What's next? Impose fine again for those who jaywalk? Nothing better to do. What a peaceful city afterall. U're the best.