Gastroenteritis - salmonellosis

What is salmonellosis?

Salmonellosis is a form of gastroenteritis caused by the germ (bacterium) Salmonella.

Salmonellosis can affect anyone; however most cases occur in children and young adults. The severity of symptoms depends on the number of bacteria you ingest, your age and your general health. You may be more prone to salmonellosis if you are elderly, have another medical condition (such as a weakened immune system) or are malnourished.

Symptoms of salmonellosis

Symptoms of salmonellosis usually occur between 6 to 72 hours after you ingest the bacteria. The most common symptoms include:

• diarrhoea, which may contain blood or mucous
• fever
• headache
• stomach cramps
• nausea
• vomiting
• dehydration, especially among infants and the elderly.

In rare cases, septicaemia (blood poisoning) may develop as a complication of salmonellosis.

Causes of salmonellosis

Salmonellosis occurs when Salmonella bacteria are taken in by mouth. This may happen in any of the following ways:

• eating undercooked meat, especially poultry, and raw or undercooked eggs
• eating cooked or ready-to-eat food that has been contaminated with Salmonella bacteria from raw food, such as raw chicken. This is called cross-contamination and can also happen when food comes into contact with contaminated kitchen surfaces, such as chopping boards, knives, serving spoons or other utensils that have been used for raw food
• if people with salmonellosis have Salmonella bacteria in their faeces and do not wash their hands properly after going to the toilet, their contaminated hands can spread the bacteria to surfaces and objects that may be touched by others, or food that will be eaten by others. Hands can also become contaminated when changing the nappy of an infected infant
• pets and farm animals can have Salmonella bacteria in their faeces without having any symptoms. People can get salmonellosis from these animals if they do not wash their hands after handling them.

Although the illness usually only lasts for a few days, the bacteria may still be present in your faeces for several weeks. One per cent of adults and 5% of children may carry the bacteria for more than a year.

Diagnosis of salmonellosis

To find out if you have salmonellosis, the doctor will ask you for a stool (faeces or poo) sample for testing. If the results show that you have salmonellosis, the doctor will be able to provide advice and appropriate treatment (if required) and will notify the Department of Health, Victoria.

If you think you got the infection from contaminated food, contact the health department of your local council. Keep any leftover food that you believe may have caused you to become ill as this will help trace the source of the bacteria. Food-borne outbreaks of salmonellosis do occur, and tracing the source is an important public health responsibility of the Department of Health.

Prevention of salmonellosis

To help protect yourself and others from salmonellosis:

• Thoroughly cook food derived from animal products – especially poultry, pork, eggs and meat dishes.
• Don't use dirty or cracked eggs.
• Keep your kitchen clean. Raw foods can contaminate surfaces.
• Store raw and cooked foods separately.
• Wash and dry hands thoroughly with soap and hot running water for 20 seconds or longer before handling food.
• Store high-risk foods at or below 5 °C or at or above 60 °C to prevent growth of bacteria.
• Do not handle cooked foods with the same utensils used for raw foods, unless they have been thoroughly washed between use.

To prevent the spread of infection:

• Keep children home from school, childcare or kindergarten until symptoms have stopped.
• Food handlers, childcare workers and healthcare workers must not work until symptoms have stopped.
• Clean bathrooms and other surfaces regularly.

Pet food and food safety

Research undertaken by the Victorian Department of Health has shown that pet food can sometimes be contaminated with Salmonella or Campylobacter bacteria. The risk is greater for dried or raw pet foods, but all pet foods should be handled with care.

This means that you should take the same care handling pet food in the kitchen as you do with human food, with some added safety tips:

• Freeze raw pet food in clearly marked containers until you are ready to use it.
• Defrost pet food in sealed containers in the fridge. Use the lower shelves, to ensure that the pet food doesn’t drip juices onto cooked food or raw vegetables.
• Wash your hands before and after handling pet food.
• If possible, don’t use the same utensils to prepare human food – keep dedicated utensils. If this isn’t possible, use utensils that you can wash in hot soapy water to reduce potential cross contamination. Take care to reduce any risk of contaminating kitchen items like sponges, tea towels and sinks.
• Throw away any food your pet doesn’t eat.
• If you play with your pet after they have eaten, it is more important than ever to wash your hands carefully after play, and to avoid your pet licking your face and mouth.

Where to get help

• Your GP (doctor)
• Nurse-on-Call Tel. 1300 606 024 – for expert health information and advice (24 hours, 7 days)
• Your local council health department
• Communicable Disease Section, Department of Health, Victorian Government Tel. 1300 651 160
• Food Safety Hotline Tel. 1300 364 352
• Food Standards Australia New Zealand Tel. (02) 6271 2222