Public health officials tackling a large number of apparently linked cases of E. coli infection in south Wales believe that the incidence has peaked.

As Farmers Weekly went to press E. coli 0157-induced illness had been confirmed in 122 people.

Most were children from more than 30 primary schools in the Rhondda Cynon Taf, Merthyr Tydfil, Caerphilly and Bridgend areas.

About a quarter of the victims required hospital treatment. Dr Brian Gibbons, Welsh Assembly minister for health and social services, said a multi-agency outbreak control team was involved in a widescale, in-depth investigation into the source of the infection.

“The team established a link between cooked meats supplied by a Bridgend company, John Tudor and Son, and the cases of illness,” Dr Gibbons told assembly members.

“It is important to stress that this does not mean that those products are necessarily the cause of the outbreak.”

In a written statement John Tudor and Sons claimed that it was under investigation for the first time in its 50-year trading history, and that none of the microbiological tests conducted had revealed the presence of E. coli 0157 on its premises.

Welsh farming unions would not comment on the likely source of the outbreak.

But they insisted that primary producers put safe, high quality meat into the food chain, and that schools should have the option to buy fresh rather than highly processed meat products.