The Food and Environmental Hygiene Department (FEHD) has conducted microbiological and chemical testing on some 54 000 food samples in 2002 and the results show that food safety remained at a very high standard. The overall failure rate for both microbiological and chemical testing was 0.3% against 0.7% and 0.5% in 2000 and 2001 respectively.
While microbiological tests target at pathogenic bacteria and viruses, chemical tests are for the detection of natural toxins, food additives and contaminants.
Regarding microbiological tests, about 19,000 food samples were analysed with pathogens found in 19 samples. This amounts to a failure rate of 0.1%, compared with 0.3% in both 2000 and 2001.
The pathogen-food combination deserving particular attention was the bacterium Enterobacter sakazakii in an infant formula specially prepared for babies suffering from acute diarrhoeal diseases. Cases in foreign countries have shown that vulnerable infants like hospitalized prematures, low birth-weight and babies with underlying medical conditions can fall ill after consuming infant formula contaminated with the bacterium. While FEHD will remain vigilant by closely monitoring scientific developments and introducing them to every day surveillance work so as to safeguard the community's food safety, manufacturers are urged to exercise due diligence as well. By introducing a risk-based and proactive sampling and laboratory analysis programme for Enterobacter sakazakii, the department was able to detect, trace and, with the cooperation of the trade and the community, contain the contamination within a short time, and no such infection had been reported.
The next pair of culprits was Norwalk-like virus in ready-to-eat oysters. Infection by this virus can result in what is known as 'winter vomiting disease'. Outbreaks usually occur in winter and the clinical presentation can be dramatic as victims are generally many and they typically have projectile vomiting in addition to other gastrointestinal symptoms.
Turning to chemical analyses, about 35,000 food samples were tested in 2002 and 140 were found unsatisfactory, representing a failure rate of 0.4%. It is encouraging to see the figure continuing to fall from 0.9% in 2000 to 0.6% in 2001. In March 2002, a non-permitted sweetener, stevioside, was found either on sale in the market or contained in food items being sold. As a result, certain brands of foods, ranging from pure sweeteners to seasonings, instant noodles to snacks, had to be recalled from consumers.
Only four food samples were found to contain the banned beta-agonists, clenbuterol and salbutamol in 2002, compared with 53 and 25 in 2000 and 2001 respectively. The improvement attributed to the department's persistent efforts to both education and enforcement.
For biotoxins, there were three failed samples for ciguatoxin and one for paralytic shellfish poison (PSP) in 2002. In 2000 and 2001, the figures were 47 and 10 for ciguatoxin and three and five for PSP respectively. Despite the significant improvement, we must continue to be on the alert as ciguatoxin and PSP are natural toxins, and their presence and levels in coral reef fish and shellfish can be very unpredictable. There are seasonal patterns in Hong Kong with peak periods in spring and the transition from summer to autumn respectively. Coral reef fish commonly found to cause fish poisoning are flowery grouper, tiger grouper, leopard coral grouper and moray eel.