Highly pathogenic avian influenza has spread to a seventh poultry farm near Melbourne, the government of Australia's Victoria state said on Monday.
Six of the properties have an H7N3 flu strain and a seventh has an H7N9 strain, it said. Neither is the H5N1 type of avian flu that has infected billions of wild and farmed animals globally and raised fears of human transmission.
"Restricted and control areas are in place surrounding all infected premises," Victoria's agriculture department said in a statement.
The infected properties include six egg farms and a duck farm. Around 1 million chickens, roughly 5% of Australia's egg-laying flock, have been or will be killed at affected farms to contain the virus, the government said last week.
There has not yet been any shortage of eggs, though some retailers have put in place limits on purchases.
Before the latest cases, the first of which was reported last month, Australia had experienced nine outbreaks of highly pathogenic avian influenza since 1976, the government says. All were contained and eradicated.
Authorities say duck and chicken eggs and meat remain safe to eat.
