* First highly pathogenic case since 1997
* Egg farm cordoned off (Adds details, background)
PARIS, Nov 15 (Reuters) - Australia has reported its first case of a highly pathogenic bird flu virus in 15 years at an egg farm in the New South Wales region, the World animal health body OIE said on Thursday.
So far 5,000 poultry have died in the infected farm in Maitland, 160 km (100 miles) north of Sydney, but 50,000 are at risk, a report by the Australian agriculture ministry to the Paris-based OIE said.
The virus, detected last week, is different from the deadly H5N1 strain, which was first detected in 1997 in Hong Kong and has since devastated duck and chicken and caused hundreds of deaths.
It is of the "H7" strain but the exact type of H7 had not yet been determined, the ministry said.
Australia faced an outbreak of bird flu in February that led to a ban on Australian exports of poultry products to Japan but that was not a highly pathogenic virus.
Most avian influenza viruses do not cause disease in humans. At least one type of "H7" strain, the H7N7 subtype, can infect people and even kill but the impact on humans usually tends to be mild, the World Health Organisation said.
The farm has been placed under quarantine as experts try to find the source of the virus, often wild birds, the ministry said. (Reporting by Sybille de La Hamaide; additional reporting by Gus Trompiz; Editing by Brian Love)