State and territory food regulators, health authorities and agriculture departments in Australia are investigating a rare strain of Salmonella (Salmonella Enteritidis) associated with human illness and egg consumption.
Public health officials investigate Salmonella outbreaks using a nationally standardised questionnaire, and coordinate epidemiological investigation through OzFoodNet. DNA Genetic fingerprinting is performed on Salmonella bacteria isolated from ill people by using whole genome sequencing (WGS), which gives a more detailed DNA fingerprint picture than any other typing method. WGS performed on bacteria isolated from ill people showed that they were closely related genetically.
This means that ill people in this outbreak were more likely to share a common source of infection. Confirmed human cases linked to this strain have been found in NSW, Victoria, Queensland and Tasmania. As at 17 June 2019 there are a total 235 human cases linked to this outbreak, of which 224 have been confirmed by WGS.
Onset of illness ranges from 18 May 2018 to 23 May 2019. The majority of human cases reside in NSW, but cases have also been detected in Victoria, Queensland, Tasmania and South Australia. Some of the cases from outside NSW are believed to have been infected when travelling in NSW.
Detections of this strain have also occurred on chicken layer farms in NSW, and one farm in Victoria. Food Standards Australia New Zealand (FSANZ) is coordinating the response by food regulators under the National Food Incident Response Protocol.
The investigation has already resulted in a small number of food recalls coordinated by FSANZ, in the first half of this year and in September last year. Biosecurity measures and other regulatory action are being applied to affected farms by the relevant authorities.
It is important to know that not all eggs are impacted, but if you have purchased recalled eggs, we recommend that you return the products to the place of purchase for a full refund, or discard the eggs into your garbage, and not into your garden. You should not feed these eggs to your pets, or livestock.
Australian authorities will continue to monitor and respond to this issue.
What symptoms does salmonellosis cause?
Symptoms of salmonellosis are usually limited to mild gastroenteritis but may include fever, headache, diarrhoea, abdominal pain, nausea and vomiting. Patients usually recover within a week. But the illness can lead to systemic illness and other longer-term conditions.
Severe cases of diarrhoea can lead to significant dehydration which may require hospitalisation and medical intervention such as intravenous fluid replacement.
Although uncommon, long-term effects may occur include reactive arthritis.
This strain can be passed from person to person, however, this is more likely to occur in young children due to poor hand hygiene.
What if I have eaten affected eggs?
It is unlikely you will get sick if you have eaten eggs that have been handled safely and cooked thoroughly.
If you are concerned about your own health or your family's health, see your doctor.
How can I prevent getting sick from Salmonella?
To prevent illness:
- Keep hands and equipment clean when preparing and eating food.
- Avoid cross contamination ∑ for example use separate cutting boards and knives for raw and ready-to-eat food, and store cooked food separately from raw foods.
- Cook eggs thoroughly.
- Avoid using dirty or cracked eggs and wash hands after handling eggs.
I have thrown away the packaging. Is there another way to identify affected eggs from the March 2019 recall?
Affected products can also be identified by stamps. See the recall notices (linked below) for these details.
If in doubt, we recommend ensuring you handle eggs safely and cook them thoroughly. Alternatively, discard eggs into the bin, and not into your garden.