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The Department of Health Promotion and Disease Prevention has been performing monitoring and investigation of food related illnesses for many years. 2008 registered a 55% rise in laboratory confirmed Salmonella cases over the average of the previous nine years.

This may in part be the result of higher number of individuals who are suffering from Salmonella being admitted to our hospitals for medical treatment. It most likely reflects a real rise in the number of cases. The real figure however cannot be known as many infections are self-treated. This is a common feature in most countries. Children less than 5 years are the most likely to suffer from Salmonella.

Over half of all food poisonings in Malta are known to originate from households. It may be hard to admit that bacteria-causing illness from contaminated foods might have come from your own home!

Salmonella infections are not uncommon and result from improper handling of food. Salmonellosis affects children as well as adults and might cause a high fever, headache, nausea, vomiting, abdominal pain and diarrhoea. Stools may become greenish or bloody. The illness usually develops 6 – 72 hrs after the ingestion of contaminated food. The illness may last a few days to a few weeks.

Salmonella infections are often self limiting and may even present as mild cases lasting one or two days. Therefore it may be common for persons not to seek medical advice as they treat their perceived ‘gastric flu’ with over the counter preparations. Antibiotics are usually not indicated except for particular severe cases. In some cases long-term sequelae can occur such as reactive arthritis.

It should be mentioned however, that children, the elderly, persons with chronic diseases and those who are immunocompromised (e.g. persons on chemo- or radiotherapy or who are HIV positive) may suffer severe illness that might also prove fatal.

The Europe-wide infectious disease surveillance system (TESSy) has had a total of 165,032 confirmed and reported cases of human salmonellosis in 2006. (EFSA- Community summary report 2006). Some European countries have shown decreasing trends of salmonellosis whereas many others have maintained relatively stable rates. Country rates may not be comparable because of different notification and surveillance systems within European countries.

1.4 million Salmonellosis is estimated to occur each year in the USA, with about 40,000 reported cases. An estimated 400 deaths from salmonella occur annually in USA. (CDC).

Salmonella bacteria live in the intestinal tracts of humans and animals including domesticated animals and birds. Transmission to humans can occur directly from animals but more often by eating foods contaminated by animal faeces. The most common sources for this type of transmission are foods of animal origin such as chicken, pork, beef and eggs. However any type of food such as vegetables can become contaminated with salmonella.

The pasteurisation of milk and treatment of service waters have come a long way in reducing salmonella transmission. Improvements in farm animal hygiene and in slaughter plant practices and in vegetable and fruit harvesting and packing have helped reduce contamination of foods. Food industry and food handler workers have regular courses to update their practices in food hygiene and safety.

Any food-handler having symptoms of vomiting and/or diarrhoea must refrain from working until 48 hrs after the symptoms have subsided. Food handlers with gastroenteritis should inform their employer. Persons suffering from these symptoms can transfer bacteria after making use of the toilet to food if they do not practice strict personal hand hygiene. Bacteria will be predominant around and beneath nails.

How does one prevent salmonella infections? The answer is simple and four fold:

1. Wash and clean well

Salmonella bacteria are hardy and can survive for weeks outside a living body if they find favourable conditions. However cleaning kitchen utensils and chopping boards after handling raw meats with simple warm water and soap, rinsing well under running water and then leaving to dry properly will eliminate all risks.

Of course all kitchen surfaces potentially contaminated with raw meats and poultry need to be cleaned in the same manner. If using utensils soon after washing, drying them is a must. Drying kitchen surfaces with a paper towel will similarly help to reduce risks further.

Hands should be washed before handling food and between handling different food items especially uncooked foods.

All fruits and vegetables should be washed thoroughly with running water before being eaten.

2. Separate raw foods from any other foods.

Raw foods must be separated from ready to eat foods (e.g. cheese, ham), any cooked foods or treated and cleaned raw foods such as salads at all times. Thawing of meats in the refrigerator should be done in the lower compartments (shelf), in food grade containers (plastic or glass containers that can be covered by a tight fitting lid) and never should thawing meats drip their liquid component onto other foods.

Separation of foods is also important during the preparation phase of foods. It is better if chopping boards of different colours or shapes are used for particular functions such as one for raw meats and another for vegetables. The use of separate knives for the different functions eliminates the need of having to wash them before using them immediately after within a busy time frame. These actions prevent what is called cross-contamination.

3. Cook all meats and eggs properly for a sufficient length of time

Any bacteria found on raw food can be killed by proper cooking and is the sure way to protect against Salmonella infection. It is recommended that food be heated for at least ten minutes at 75 °C (167 °F) i.e. until the center of the food reaches this temperature. Thus cooking foods to the boiling point is just right. The changes in texture and colour, which happen as food is cooked, mean that you can usually tell when the food is safe. Checking that this change goes right through will ensure thorough cooking and safety. Meat that is still pink at the centre means that bacteria there may still survive and be capable of causing illness.

Reheating foods should be done in a similar manner. Of course cooking times will vary according to the type of food, for example large chunks of meat will need a longer cooking time period for the core to reach the desired temperature and be cooked well.

4. Chill food adequately

We keep foods in the fridge or freezer to slow bacterial growth or arrest their growth respectively and thus foods can be kept safe for longer periods rather than hours. Salmonella is not destroyed by freezing and will start to grow again when food defrosts. Therefore defrosted raw meats can still carry the risk and during preparation care must be taken to prevent cross contamination (see 2 above).

Therefore do not keep foods at undue temperatures for long periods of time. In general keep foods at room temperatures not longer for one hour in the summer months and no longer than two hours in the cooler months.

Contaminated foods look and smell normal. One should assume that all raw meats especially chicken, pork and eggs can be potentially contaminated with salmonella. Therefore always cook well and to the core. Always cook eggs thoroughly until the egg yolk is hard either when frying or boiling them. Never eat products made of raw eggs. Pasteurized egg products are an alternative.

Other important foods that have a high risk of contamination with salmonella and other food borne illness-causing bacteria are foods containing raw minced meat. Examples are local traditional sausages and hamburgers. These should always be well cooked before consumption.

It is well known that reptiles such as turtles, iguanas etc. can harbour Salmonella without any harm to them. It is virtually impossible to eradicate these bacteria from reptiles. These pets should not be in the same house as an infant and are not appropriate pets for small children. As a rule always wash your hand after petting or touching any type of animal.

People with symptoms of diarrhoea and vomiting should not prepare foods until 48 hours after symptoms resolve. People whose personal hand hygiene is highly doubtful can transfer bacteria from their own faeces on to foods! Therefore always wash your hands well after using the toilet.

Food handlers with similar symptoms should be extra careful in this regard. Notified food handlers have their stools tested by the department to show that they no longer carry the harmful bacteria before they return to work, hence protecting the consumer.

Salmonella is preventable. If we follow simple rules of food safety and food hygiene than the consequence would be better health for us and our families.