LONDON : Doctors are carrying out tests on a second person who worked at a British factory farm where the potentially deadly H5N1 strain of bird flu was detected, public health officials said on Wednesday.

The announcement from the Health Protection Agency (HPA) came just hours after it revealed that a vet said to have been involved in clearing up at the turkey farm plant had tested negative for the disease.

"We are not expecting any workers to test positive for avian flu as they have followed all the necessary precautions in terms of protective clothing, hygiene measures and have been offered antiviral drugs," said HPA flu expert Doctor Jonathan Van Tam.

"We are, however, expecting to see a number of workers with symptoms caused by other non-flu respiratory viruses over the coming week as this is the time of year when we see an increase in these infections.

"We will assess these cases as they occur and expect to be carrying out more testing through the course of this week."

The HPA added that the results of the test on the second worker would be released on Thursday.

The first was put in an isolation unit in a hospital in Nottingham, east central England, after suffering mild respiratory problems but has now been allowed to go home, the HPA said earlier.

This man, named by British media as Gordon Young, was a state vet said by Sky News television to have taken blood samples from the 159,000 birds gassed at the farm in Holton, Suffolk, eastern England, after H5N1 was confirmed on Saturday.

The highly virulent strain of H5N1 has killed at least 160 people worldwide, most of them in southeast Asia.

The farm is run by Bernard Matthews, Europe's biggest turkey producer.

Vets completed a cull of all birds at the plant on Monday.

Movement restrictions for poultry are still in place around the farm and the wider area. - AFP/de