A safe feed

Everyone needs to eat to live. Yet the food consumed can be a source of illness, which is self-limiting on most occasions. However, there are instances when people have died from the food they ate.

Everyone is at risk of foodborne illness, irrespective of where they live. There are about 200 food-borne diseases. Media reports on the E. coli outbreak in Germany, melamine contaminated milk in China and the high percentage of bacterial contamination of food sold during Ramadhan are reminders of everyone's vulnerability.

Soon et al in a "Review of food borne diseases in Malaysia" stated that "Half of the food borne related diseases from the early 1990s until today were associated with outbreaks in institutions and schools, mostly due to unhygienic food handling procedures ... the main contributing factor to food-borne diseases was identified as insanitary food handling procedures which accounted for more than 50% of the poisoning episodes." (Food Control June 2011: 22; 6: 823-830)

Food-borne diseases affect the young, elderly and the sick more than others and can lead to a vicious cycle of diarrhoea, malnutrition and even death. It has a negative impact on the healthcare delivery system and economic productivity.

There have been changes in the patterns of foodborne illness. The traditional patterns of localised illness, easy isolation of the causative agent, low mortality and easy treatment with antibiotics are not infrequently replaced with widespread illness, difficulties in isolating the causative agent, high mortality and antibiotic resistance.

The majority of food-borne diseases are preventable with proper food handling, preparation and storage. The authorities are doing their part. However, this article is about what we as individuals can do to ensure that the food we eat is safe.

Foodborne illnesses

Foodborne illnesses

Foodborne illnesses are defined as diseases, usually either infectious or toxic in nature, caused by agents that enter the body through the ingestion of food. There are about 200 illnesses that are foodborne.

There are several infectious diseases that are foodborne. The major bacterial infections are salmonella, E. coli, campylobacter and cholera. The Health Ministry's 2009 data reveal that the incidence per 100,000 people for cholera, dysentery, food poisoning, typhoid and hepatitis A were 0.98, 0.54, 30.17, 1.07 and 0.14 respectively, with mortalities reported for cholera and food poisoning.

Salmonella bacteria cause typhoid, paratyphoid and enteritis. The common foods involved include poultry and other meats, milk, eggs and chocolate.

E. coli is a common cause of food borne illness. The bacteria causes gastroenteritis, urinary tract infections and meningitis in the newborn. The emergence of strains that cause intestinal bleeding (enterohaemorrhagic) in recent years have led to severe and occasional fatal consequences, especially in the young and elderly. Although not common, these strains are one of the most serious food-borne illnesses.

Campylobacteria is a common cause of enteritis. The common foods involved include milk, raw or undercooked poultry, and drinking water. It may lead to chronic health problems, eg arthritis, and neurological disorders in 2% to 10% of those infected. Gastrointestinal perforation is a rare complication of infection of the ileum, which is at the end of the small intestine.

Cholera, which is caused by the bacterium, Vibrio cholerae, is a major public health problem in many developing countries. It is a water and foodborne disease. The common foods involved include rice, vegetables and various seafoods. If untreated, cholera leads to severe hydration and even death.

Poisonous toxic material can also get into our food and cause illness. They include natural occurring toxins, metals, environmental pollutants, pesticides, chemicals used for feeding or treating animals or cleaning and illegal food additives.

Naturally occurring toxins, eg mycotoxins, cyanogenic glycosides and toxins in poisonous mushrooms sometimes cause severe illnesses.

Metals, eg lead and mercury, which contaminate food through air, water and soil pollution, damage the nervous system and kidneys in the children and the elderly.

Organic pollutants which are unwanted industrial byproducts and waste incineration e.g. dioxins and polychlorinated biphenyls can accumulate in the environment. These pollutants may lead to various adverse effects in people exposed to it.

Changes in animal husbandry practices have led to disease in humans. For example, bovine spongiform encephalopathy (BSE or "mad cow disease") have been attributed to the increased use of bone and meat as food supplements for cattle. Furthermore, the addition of antibiotics to animal feed has led to concerns about the transfer of antibiotic resistance to bacteria that infect people.

Illegal food manufacturing practices like the addition of melamine to increase the protein content of milk have led to acute kidney damage in children.

Symptoms

Clinical features

The symptoms depend on the causative agent and are usually experienced between one to three days after consumption of the food. However, there may be a longer incubation period in some food-borne illnesses. The common symptoms are diarrhoea, vomiting and abdominal pain. The majority of infections resolve by itself and all that is needed is drinking large amounts of fluids to avoid dehydration.

However, about 3% of food borne illnesses result in long term health problems like kidney damage, arthritis, neurological disorders and even death.

It is vital to seek medical attention if the bowel movements are very frequent, very watery, bloody or lasts more than three days.

Keeping clean

Although food may appear clean, it does not mean that it is safe. It has been estimated that about 2.5 million bacteria are needed to make 250 ml of water appear cloudy while it takes about 15 to 20 bacteria to cause illness.

Cleanliness involves washing hands before handling food and often during its preparation, washing and sanitising all utensils and surfaces used for food preparation, protecting the food and kitchen from pests or animals, and always washing the hands after going to the toilet.

Food should be cleaned during its preparation together with the utensils and surfaces used, particularly when there has been contact with raw meat or seafood. After the meal, the excess food should be put into bin with a cover. The dishes and utensils used should be cleaned with detergent and running water and wiped with a clean dry cloth or left to air-dry.

Food should be kept from pests or animals by covering them, putting them in closed containers, removing rubbish regularly, using insecticides or baits (while making sure they do not contaminate the food) and keeping domestic pets away from food preparation areas.

Washing hands after going to the toilet prevents the contamination of food by faecal material.

Proper cooking

Proper cooking will result in the death of most dangerous micro-organisms. It is known that food cooked to a temperature of 70 degrees Celsius is safe for human consumption as large concentrations of micro-organisms are killed at this temperature within 30 seconds. Particular attention should be given to meat, poultry, sea foods and eggs.

Care must be taken if a microwave oven is used as the temperature in the food may be unevenly distributed. It is noteworthy that certain plastic containers cannot be used because they release dangerous chemicals in the microwave oven.

If a thermometer is unavailable, poultry should be cooked until the insides are no longer pink, eggs and seafood until they are piping hot, and boiling liquids for an additional minute after they have come to a boil.

Cooked food consumed some time after it has been cooked should be reheated before eating.

Raw food

Safe water and raw food

Safe water and raw food are vital in ensuring food safety. The treatment of water with specified amounts of chemicals and its filtration by the authorities helps in the inactivation of micro-organisms but it is the boiling of water that kills most dangerous micro-organisms. One should not drink or use untreated water from rivers or canals as they contain micro-organisms and parasites.

Raw food should be selected carefully. Fruits and vegetables have to be fresh. Meats and poultry should be slaughtered in hygienic facilities maintained by the authorities. If fruits and vegetables are eaten raw, they must be washed carefully before eating, after throwing away the parts that appear rotten or mouldy. Food that appear damaged or rotten, are mouldy or past its expiry date should not be eaten.

Separate raw and cooked food

Raw and cooked food should be kept separated to prevent the transfer of micro-organisms from the raw to the cooked food. This can be done by using separate dishes and utensils and storing them separately in containers with lids. This should be done at the time of purchase of the food and during its preparation.

Keep food at safe temperatures

Cooked food should be served piping hot and not kept a room temperature for more than two hours. If not consumed immediately, all cooked food as well as perishable foods should be kept refrigerated, preferably below 5 degrees Celsius. This is because micro-organisms multiply rapidly at room temperatures with slower or cessation of growth at temperatures above 60 or below 5 degrees Celsius.

Food should not be stored in the refrigerator for too long. If refrigeration is unavailable, fresh foods should be cooked and consumed immediately.

Thawed food should be cooked without delay.

Food safety involves everyone, i.e. the authorities, companies and people who produce, process, transport, or sell food, and consumers. All have responsibilities for taking the necessary measures to identify and control the hazards that may make the food unsafe. Although proper precautions are taken in most instances, it only takes one slip to cause an outbreak which may lead to fatalities.

Everyone, as consumers, have a responsibility to themselves and their families to ensure food safety by proper handling, preparation and storage. The measures that can be taken are simple and inexpensive.

Dr Milton Lum is a member of the board of Medical Defence Malaysia. This article is not intended to replace, dictate or define evaluation by a qualified doctor. The views expressed do not represent that of any organisation the writer is associated with.