Listeria found in meal distributed by Meals on Wheels

21 October 2011

• A meal subsequently found to be contaminated with Listeria monocytogenes has been distributed to approximately 500 persons by Meals on Wheels on October 7.
• Medical practitioners are encouraged to be alert for listeriosis in greater Adelaide residents who receive Meals on Wheels.
• Listeriosis in the elderly and immuno-compromised may present with septicaemia and/or meningitis. Symptoms can include fever, headache, backache, nausea, vomiting, neck stiffness, confusion and decreased alertness.

Meals on Wheels conducts routine testing of samples of prepared foods distributed to clients. A sample of food has grown Listeria monocytogenes that may be of sufficient quantity to cause illness in susceptible persons. This meal was distributed on 7 October to approximately 500 persons across greater Adelaide. Meals on Wheels are in the process of informing clients who may have received the meal.

The incubation period for listeriosis is three to 70 days, with an average of three weeks. Medical practitioners are asked to be alert for possible cases of listeriosis amongst greater Adelaide residents who receive Meals on Wheels until mid December.

Exposure to Listeria monocytogenes usually results in no or mild illness, but infection may be more serious in the elderly, particularly if immune suppressed, other immune suppressed people, pregnant women and neonates.

Listeria monocytogenes infection may cause sepsis, meningitis or meningo-encephalitis. Symptoms include: 

• sudden onset of fever
• headache
• backache
• nausea
• vomiting
• neck stiffness
• gradual confusion or decreased alertness. 

Admission to hospital for antibiotic therapy may be necessary.

If you strongly suspect listeriosis in an unwell patient please discuss the case with an infectious diseases physician. Listeriosis is diagnosed by culture of Listeria monocytogenes from a sterile site such as blood or cerebrospinal fluid. Stool samples are not recommended for diagnosis of Listeria. Please also notify CDCB on 1300 232 272 as listeriosis is a notifiable condition.

Listeria is able to multiply in refrigerated foods. Foods that may be associated with the spread of Listeria include:

• cold meats
• pâté
• salad
• raw and smoked seafood
• soft, semi-soft and surface ripened cheeses
• soft serve ice cream
• unpasteurised dairy products. 

There is no person-to person spread of Listeria monocytogenes (except trans-placental).

A listeriosis fact sheet for the public is available at:
http://www.health.sa.gov.au/PEHS/ygw/listeriosis-pehs-sahealth-2009.pdf Meals on Wheels have set up a 24 hour information line on 8273 1308 with information also on their website www.mealsonwheels.org.au.

If you require further information please call 1300 232 272 (24 hours / 7 days

Dr Doug Shaw – A/Director, Communicable Disease Control Branch