Salmonella investigation is intensified as number of cases reaches 34

The number of confirmed cases in the salmonella outbreak in the north-east has now reached 34. The investigation into the outbreak, which is linked to cooked ham, has been intensified.

Officials from the Food Safety Authority of Ireland and the Department of Agriculture yesterday surveyed abattoirs and pig farms in Meath, Cavan and Louth in an effort to determine the outbreak's source.

Ten people who were in hospital have been released after treatment but the total number of people affected is estimated to be many times the confirmed total.

The main focus of the investigation was on abattoirs that may have supplied the Augherskea Meats plant in Navan, Co Meath, which is being linked to the outbreak. It was then extended to farms from which pigs may have been supplied, according to Mr Pat O'Mahony, FSAI chief specialist for veterinary public health.

The plant's cooked meats section is temporarily closed and will not reopen until allowed to do so by the North Eastern Health Board, though its raw meat output is unaffected.

Meanwhile, health board members were briefed on the extent of the outbreak at a meeting in Kells, Co Meath, when it was confirmed that over 400 calls have been received by the board's helpline since Friday. The possibility that the salmonella strain may have arisen from a number of sources other than the meat plant has not been ruled out.

The worst food poisoning outbreak this year has prompted the FSAI to ask people suffering vomiting, stomach cramps or diarrhoea in the affected counties to contact their doctor in an effort to trace the source.

Tighter salmonella controls have begun to be introduced in processing plants exporting meat products ahead of those supplying the home market. But tighter regulation of all processing plants and improved classification of herds on farms are now likely. This is because smaller plants were implicated in two previous outbreaks involving cooked ham, the same strain responsible for this latest outbreak in Dundrum, Co Dublin, and in Loughrea, Co Galway, in 1998.

The Labour spokeswoman on consumer affairs, Dr Mary Upton, a food microbiologist, said aspects of the outbreak were "very worrying" from a public health perspective. Such at outbreak should not happen with cooked ham, as any salmonella should be eliminated by cooking, while the salt used in processing should also help. "In spite of a lot of talk, it has shown up gaps in food safety training and in salmonella controls. We have been lucky up to this rather than effective."

Some large exporting companies have introduced measures to classify herds by testing pigs entering their processing units. If pigs are found to have particular antibodies, it means they were exposed to salmonella at farm level. Based on test results, farms can be classified as "salmonella-free", "low-risk" or "high-risk". This may determine if pigs are bought for export or not. .

Meanwhile, small abattoirs are to be subjected to increased surveillance, though 10 counties still have to employ local authority vets, who play a key role in inspecting them.