Eggs are ubiquitous in our daily meals - breakfast, lunch, dinner, and pastries and desserts, too. But eggs are also linked commonly to Salmonella food poisoning.
So how risky, in Salmonella contamination, are such everyday egg dishes favoured by the local - minced beef with raw egg rice （窩蛋免治牛肉飯）, shrimp with scrambled egg rice （滑蛋蝦仁飯）, crab meat in scrambled egg white （賽螃蟹）, ham omelette, fried eggs with sausage, tiramisu and chocolate mousse, to name but a few of the most common?
To assess the extent of the risk, the Consumer Council, in collaboration with the Centre for Food Safety (CFS), have sourced 100 egg dish samples in total, between June and July this year, from eateries across Hong Kong.
The samples were analysed by the Department of Health's Public Health Laboratory Services Branch for detection of the bacteria, Salmonella.
The results of the test showed Salmonella was not detected in any samples in the study. However, it is also noted that there were some study limitations e.g. a limited number of samples was included and the samples only focused on specific types of food.
According to the CFS Microbiological Guidelines for Food, in general, the microbiological quality of a ready-to-eat food sample will be considered "unsatisfactory" i.e. potentially injurious to health and/or unfit for human consumption if Salmonella is detected in 25 g of the sample.
Though there was no test sample found "unsatisfactory", a word of caution is sensible to bear in mind. Salmonella is commonly present in eggs and other food of animal origin, mainly meat, poultry and raw milk, and is known to be an important causative agent for food poisoning outbreaks in many countries worldwide, including Hong Kong.
According to the data of the Department of Health, between 2010 and August this year, there were 83 confirmed cases of food poisoning outbreaks caused by Salmonella, of which 38 cases (46%) were associated with eggs or food items with egg as an ingredient. The above figures do not represent the full picture of burden borne by Salmonella infections in Hong Kong as they do not include those sporadic infections not involving outbreaks that are not reportable in Hong Kong.
The onset of Salmonella food poisoning normally occurs anytime from 6 to 72 hours after ingestion of the bacteria, with symptoms including nausea, fever, abdominal pain, diarrhea and vomiting.
The illness generally lasts from 2 to 7 days; usually patients will make a recovery without any specific treatment in most cases.
However, the infection can become severe and even life-threatening, in some cases, particularly in very young children, the elderly and the immuno-compromised (people with weakened immunity).
Consumers are more likely to be susceptible to a higher risk of Salmonella infection if they habitually consume raw or undercooked eggs. Sensible food and personal hygiene practices will go a long way to preventing Salmonella food poisoning. Here are a few simple tips to follow when buying, storing and cooking eggs:
- Avoid purchasing cracked or dirty eggs, choose only those with shell intact, and observe the expiry date on the package or label.
- Refrigerate the eggs promptly after purchase, and separate them from cooked and ready-to-eat food.
- Contrary to common belief, as a general rule, shell eggs need not be washed before storage under refrigeration. If eggs are found soiled with fecal matter, wash them, but cook and serve immediately.
- Ideally, eggs should be cooked until both the yolk and the white are firm. Avoid eating raw eggs particularly with the elderly, infants and pregnant women.
- Choose pasteurized eggs or their products to prepare dishes not requiring heat treatment such as egg pudding, tiramisu or chocolate mousse.
Restaurant operators are urged also to avoid the risk of cross-contamination between raw eggs and other food. Clean thoroughly all utensils, in particular the food contacting surface, used for preparation of raw eggs.
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- 2014.11.17