Processors under spotlight as food ingredient suspected in listeria outbreak

An investigation has been launched after tainted airline food was linked to a dramatic jump in listeria cases in one Australian state.

Airline Virgin Blue confirmed that chicken wraps served on some of its internal and international flights during a two-month period earlier this year were under investigation by health authorities in the state of Queensland. One report suggested that five people, including two pregnant women, had so far contracted listeriosis after eating the airline's wraps.

Contaminated ingredient

The company said it believed a contaminated ingredient supplied to the producers of the wraps was responsible for the problem. The product, which had been withdrawn from sale in June, had also been supplied to a number of other firms, said the airline

“The investigation is principally confined to supply of chicken wraps in a small period of time in May-June, 2009 in which it is believed that a batch of product provided to these companies may have contained the potentially harmful bacteria, Listeria,” said a Virgin Blue statement.

“The affected chicken wraps may have been supplied to customers on flights along the east coast of Australia and to New Zealand and Bali. It appears the likely source of the contamination was an ingredient supplied to the manufacturers of the wraps and not Virgin Blue or other companies who received the affected products.”

The company said it continued to co-operate with state and national authorities and reminded its passengers that the bacteria had an incubation period of up to 70 days.

Big increase in listeriosis cases

Queensland Health said there had been a substantial rise in listeriosis cases both across the state and nationally in 2009.

Dr Erin Groves, acting deputy director of the Queensland Health said: “In the last six months we've actually had nationally around about 56 cases, of which nine were in Queensland. Normally we would get about 50 or 60 in a whole year.”

She confirmed that the focus of the investigation would fall on meat processors whose processing and supply procedures would come under intense scrutiny.

"What we're needing to do is go out to all manufacturers that could possibly be implicated and do very extensive testing of how they process their meat, how they supply it to people who then on give it to people to consume - to actually find out whether there's things we can do to prevent further infection," Groves said.

Listeriosis is a serious infection caused by eating food contaminated with the bacterium Listeria monocytogenes, said the US Centers for Disease Control. The disease mainly affects older people, newborns, adults with weakened immune systems and pregnant women, who are 20 times more at risk of contracting the disease than other healthy adults.