Make sure that the food you eat, whether they're eggs or meat, are thoroughly cooked.

IN 1885, an American veterinary pathologist discovered a bacteria from pigs that, when ingested by humans, can cause diarrhea, fever and abdominal cramps within 12 to 72 hours.

The bacteria was called Salmonella, named after its discoverer Daniel Edward Salmon.

These days, salmonella are more commonly seen in poultry and raw eggs, and from food that has been cooked or frozen and not eaten straight away.

According to the American Centers for Disease and Control, contaminated foods usually look and smell normal. They are often of animal origin, such as beef, poultry, milk, or eggs. But all types of foods, including vegetables, may become contaminated. So it is important to keep your surroundings, especially the kitchen, clean and sanitised. There are professional cleaning services that can do this for you.

For the bacteria of animal origin, salmonella live in the intestinal tracts of humans and other animals, including birds. They are usually transmitted to humans by eating foods contaminated with animal feces.

The unwashed hands of an infected food handler who forgot to wash his or her hands with soap after using the bathroom may also contaminate food.

How do you avoid salmonella? Thorough cooking kills salmonella. They also advise people to avoid eating raw or undercooked eggs, poultry, or meat. When you go to restaurants and hawker centres, make sure that the dishes you order are well-cooked and not raw.

Take note that raw eggs may be unrecognised in some dine-in and delivery foods such as homemade hollandaise sauce, caesar and other homemade salad dressings like tiramisu, homemade ice cream, homemade mayonnaise, cookie dough, and frostings.

Poultry and meat, including hamburgers, should be well-cooked, not pink in the middle. Persons also should not consume raw or unpasteurized milk or other dairy products. Produce should be thoroughly washed before consuming.

Cross-contamination of foods should be avoided. Uncooked meats should be keep separate from produce, cooked foods, and ready-to-eat foods.

Hands, cutting boards, counters, knives, and other utensils should be washed thoroughly after handling uncooked foods. Hands should be washed before handling any food, and between handling different food items.

People who have salmonellosis should not prepare food or pour water for others until they have been shown to no longer be carrying the salmonella bacterium.

How can Salmonella infections be diagnosed?

Many different kinds of illnesses can cause diarrhea, fever, or abdominal cramps. Determining that salmonella is the cause of the illness depends on laboratory tests that identify salmonella in the stools of an infected person.

These tests are sometimes not performed unless the laboratory is instructed specifically to look for the organism. Once salmonella has been identified, further testing can determine its specific type, and which antibiotics could be used to treat it.

How can salmonella infections be treated?

Salmonella infections usually resolve in 5-7 days and often do not require treatment unless the patient becomes severely dehydrated or the infection spreads from the intestines.

Persons with severe diarrhea may require rehydration, often with intravenous fluids. Antibiotics are not usually necessary unless the infection spreads from the intestines, then it can be treated with ampicillin, gentamicin, trimethoprim/sulfamethoxazole, or ciprofloxacin.

Unfortunately, some salmonella bacteria have become resistant to antibiotics, largely as a result of the use of antibiotics to promote the growth of feed animals.

Are there long-term consequences to a salmonella infection?

Persons with diarrhea usually recover completely, although it may be several months before their bowel habits are entirely normal.

A small number of persons who are infected with salmonella, will go on to develop pains in their joints, irritation of the eyes, and painful urination. This is called Reiter's syndrome.

It can last for months or years, and can lead to chronic arthritis, which is difficult to treat. Antibiotic treatment does not make a difference in whether or not the person later develops arthritis.