US food safety inspectors have been finding a much lower rate of E. coli contamination in ground beef products this year than last year, the US Department of Agriculture has said.

The USDA said the decline was due to increased inspections of US beef plants, following the record amount of meat recalled last year.

"The agency's sampling data suggests that initiatives begun in the past year are beginning to pay dividends," Garry McKee, administrator of the USDA's Food Safety and Inspection Service, was quoted by Reuters as saying.

Of 4,432 beef samples tested in the first eight months of this year, 0.32% tested positive for E. coli 0157:H7, compared to 0.78% reported for the whole of 2002.

E. coli can cause nausea and diarrhoea, but the bacteria is destroyed if meat is cooked to at least 160 degrees Fahrenheit.

The USDA said there had been 45 meat recalls during the first eight months of this year, compared to 76 recalls in the year-ago period.