And a fourth dairy worker has contracted the disease in the United States.
ACT authorities on Friday, July 5, confirmed a group of chickens kept at the home had tested positive to the virus, the territory's second site to be affected.
The home is in a quarantine area set up after an egg facility in Canberra's north detected the virus last week.
Along with the two sites in the ACT, eight farms in Victoria and two in NSW have been forced to close to stop the bird flu spreading.
ACT Environment Minister Rebecca Vassarotti praised the home's residents for preventing further spread of the virus to the broader bird population.
"While disappointing to have a second case, it is not unexpected,“ she said.
“Like jurisdictions across the country this is unfortunately the reality of such a highly transmittable virus.
"Avian influenza is very easily transmitted by moving sick birds from property to property, as well as from contaminated boots, equipment and vehicles if proper biosecurity measures aren't in place.
"Wild birds may also be carriers of the virus."
More the one million chickens and ducks have been culled due to the outbreaks.
The spread of bird flu had prompted major supermarkets in NSW, Victoria and the ACT to introduce limits of two cartons of eggs per customer.
Fast-food chain McDonald's had also been forced to shorten its breakfast hours due to egg supply issues.
Fourth US dairy worker tests positive for bird flu
A fourth farm worker in the United States has been infected with bird flu in the growing outbreak linked to dairy cows, health officials say.
The worker had direct contact with infected dairy cows on a north-east Colorado farm, state and federal health officials said.
The man developed pink eye, or conjunctivitis, received antiviral treatment and has recovered.
Three previous cases of human infection linked to cows have been reported in dairy workers in Texas and Michigan since March.
Two of those workers also developed pink eye while one had mild respiratory symptoms.
In 2022, the first US case of bird flu was detected in a Colorado farm worker exposed to infected poultry.
The Centers for Disease Control and Prevention said the new infection "does not change" the agency's assessment that the risk to the general public remains low.
Surveillance systems tracking flu in the US have shown no unusual activity, officials said.
However, people with prolonged contact to infected birds or other animals, including livestock, or to their environments, are at higher risk of infection.
The Colorado man was being monitored when he developed symptoms because of his work with dairy cows, according to the CDC.
Tests at the state level were inconclusive but samples sent to the CDC tested positive.
Full results of genetic analysis of the sample are pending.
As of Wednesday, July 3, more than 135 dairy herds in a dozen US states had reported infections with the H5N1 virus that originated in poultry, according to the Agriculture Department.