Fourth Farm in Australia Affected by Avian Flu

Bird Flu Virus Hits Australian Farms

Avian flu first appeared in Australia in May, resulting in the loss of hundreds of thousands of poultry. To date, the disease has been detected on four farms in the state of Victoria. The H7N3 strain of the virus was identified at three of them, while the H7N7 strain was found at the fourth, which is located farther away. Each farm has been placed under quarantine, and movement restrictions are also in effect in the surrounding areas. Local poultry owners must keep their birds indoors to minimize contact with wild birds, which could be a source of the virus. However, authorities say the outbreak poses no threat to consumers of eggs or poultry meat.

The H5N1 strain is of the greatest concern due to the virus’s widespread transmission not only among birds but also among mammals, including transmission to humans. Since 2003, just under a thousand human cases have been reported, about half of which were fatal. The strain is on the list of viruses with pandemic potential, and any spread to a new mammalian species is cause for concern.

Bird Flu in the U.S. Is Causing Increasing Concern

In the U.S., since 2022, the H5N1 virus has infected more than 90 million chickens and more than 900 wild birds. This year, the virus has spread in nine U.S. states among goats and cows that had come into contact with wild birds and infected poultry. Entire herds of cows—67 herds—were infected, indicating transmission between mammals without the involvement of birds. The disease also spread to cats drinking unpasteurized milk from infected cows and to three people working on dairy farms who had contact with cattle, likely while milking the cows.

There is no evidence to suggest human-to-human transmission of the virus, though this cannot be ruled out. Symptoms in humans are mild and consist mainly of conjunctivitis and a cough. Tests are being developed to detect the virus in humans, and a mass screening of milk for the virus is planned. Retail milk may contain traces of the virus; however, these are inactivated through pasteurization, and the milk is safe to drink.