TEMPORARY restrictions have been put in place at a Suffolk poultry farm following a bird flu scare.

Animal health scientists are awaiting further tests after initial results came back negative for the H5 and H7 strains of avian influenza (AI) - both considered a potential threat to humans - at a Bernard Matthews farm.

Officials from the Department for Environment, Food and Rural Affairs (Defra) would not confirm where the tests had been carried out but said experts were called after a bird displayed respiratory problems.

They warned poultry keepers to stay vigilant and report any concerns to the animal health agency or to a vet.

A Defra spokeswoman said that both strains had the potential to be “highly pathogenic” but that tests had so far returned negative results.

Meanwhile, activities at the plant have been restricted as a precaution while further tests are completed.

A spokesperson for Bernard Matthews said: “We can confirm that some of our birds at one of our farms showed signs of ill health over the weekend. We felt it appropriate to report this to DEFRA. They have detected the presence of an avian influenza virus, but not the virulent H5 or H7 form. Some restrictions are in place as a precaution, but are expected to be lifted in the next few days.”

In 2007 an outbreak of H5N1 occurred at a Bernard Matthews farm in Holton, near Halesworth, leading to a large cull of turkeys.

H5 infections have been documented among humans, and have caused severe illness and even death, while H7 cases are rarer in humans but can occur as a result of direct contact with infected birds.

Defra has issued facts and advice on the viruses, which are categorized according to the ability to cause severe disease in avian species as either highly pathogenic avian influenza viruses (HPAI) or low pathogenic (LPAI).

The symptoms of HPAI are respiratory distress, swollen heads, dullness, a loss of appetite and a drop in egg production.

LPAI does not always cause obvious disease in birds. It is thought that influenza viruses circulate freely in the global wildfowl population.

In China, state news has reported 71 human infection, leading to 14 deaths, since the outbreak of the H7N9 variant in the country two weeks ago.

AI is spread by movement of infected birds or contact with respiratory secretions, and in particular faeces, either directly or through contaminated objects, clothes or vehicles.