Cholera and Seafood - How are we doing in seafood hygiene?

The recent outbreak of cholera in the territory raised the concern of some members of the campus community about campus seafood hygiene conditions, and in particular, the quality of sea water used by the G/F caterer who keeps live fish in tanks. This is certainly a valid concern. SEPO has been involved with the live seafood keeping issue ever since the new G/F restaurant started to operate. In this article we will explain the current arrangements to ensure good sea water quality and seafood hygiene.

 

Quality and Source of Sea Water

Recently there are several widely publicized cases where restaurants were charged for using unclean sea water for fish-keeping. Some were cited as using sea water from poorly maintained flush water tanks, others had their water delivered by contractors who pumped the water from doubtful sources, including the heavily polluted Victoria harbour or some typhoon shelters.

In this regard, we are fortunate to be located in one of the areas in Hong Kong where the sea water quality is considered to be pristine. Everyday, HKUST takes in a considerable amount of sea water just off the shore and uses it mainly for cooling of the air-conditioning system. As part of our campus environmental compliance program, sea water samples are collected monthly at selected locations near the shore.  This becomes a source of first-hand information about sea water quality. Past analytical results indicated the sea water quality in our campus sea water system to be consistently high. Therefore when SEPO was presented with a proposal from the G/F restaurant to use campus sea water supply for raising live seafood, we endorsed the idea.

Fish Tank Water Sampling

In February when the G/F restaurant just started their operation, artificial sea water using a commercial salt mixture was used, and then sea water was trucked in for a short period of time before the connection to the campus sea water supply was completed. During that initial period, SEPO sampled the fish tank water weekly for two times, on 4 February and 11 February, with one sample from each of the five tanks. The samples were analyzed for E. coli and faecal coliform counts, which are commonly accepted indicators of contamination by domestic sewage, and therefore possible human pathogens.

The results of the first batch of samples indicated the bacterial counts to be below 1 bacterium in every 100 milliliter (mL) of sea water (which is the detection limit of the analytical method) for three tanks. For the other two samples where positive readings were found (6/16 and 6/14 for E. coli and faecal coliform counts, respectively), they were well below the standard promulgated by the Regional Council, which is 610 counts of E. coli per 100 mL. In the subsequent sampling, all samples turned out to contain less than detectable amount of coliform bacteria. Based on these findings and the completion of the connection of campus sea water supply to the tanks, SEPO has reduced the sampling frequency to monthly. The third sampling was performed on 12 March, and the results again showed less than detectable amount of coliform in all water samples. In summary, the water quality in the G/F restaurant fish tanks is under close monitoring by SEPO, and results so far indicated the water quality to be consistently good.  Therefore it should not be of concern to the campus community. However, food hygiene means much more than ensuring good water quality.

What Everyone of Us Should Do

SEPO staff and CSO colleagues have always kept a close look on the hygiene conditions of campus caterers. In the wake of the cholera outbreak, we have repeatedly reminded caterers about proper handling, rearing, and thorough cooking of seafood. On the other hand, each of us should be reminded of the following:

• Remember, as the government health officials have repeatedly reminded the community, cholera is NOT limited to summer months, one should ALWAYS ensure good food hygiene practice.
• Remember to thoroughly clean and cook seafood, including fish and shellfish.
• Look out for eateries with doubtful hygiene conditions.
• If you develop diarrhea after consumption of seafood or other food of doubtful quality, immediately seek medical advice.

Cholera can be effectively treated by antibiotics and usually does not have any long term adverse effect. However, if the diarrhea is severe, and the victim does not seek medical help in time, the resulting dehydration may become fatal. Controlling the spread of the disease at an early stage so that it will not develop into an epidemic is a crucial task on a community level.  Therefore contacting the authority even when there is only a suspected cholera case is very important. Let’s eat well and stay healthy!