Australia reports imported human H5N1 avian flu case and unrelated high-path poultry outbreak

H5N1 particles

NIAID/Flickr cc

Health officials in Australia's Victoria state reported the first human H5N1 avian flu case in the country, which involves a child who contracted the virus in India and was sick in March.

In a statement, the Victoria Department of Health said the child had a severe infection but has fully recovered. Contact tracing revealed no evidence of transmission in Australia, and health officials said the risk is low, given that the virus doesn't spread easily among people.

No earlier detections in Australian animals or people

The H5N1 strain that infected the child isn't the same as the one fueling outbreaks in the United States, health officials said, noting that H5N1 had never been detected in animals or people in Australia before.

India continues to report sporadic H5N1 outbreaks in poultry, including recurrences in Andhra Pradesh and Maharashtra in February, according to a recent situation report from the World Organization for Animal Health.

Since January 2022 and through April 25, 2024, 26 sporadic human H5N1 cases have been reported from eight countries, none of them from India, according to background information from the US Centers for Disease Control and Prevention (CDC).  Fourteen illnesses were severe or critical, seven were fatal, four were mild, and eight were asymptomatic.

Most patients were exposed to sick or dead poultry. Eleven of the cases were thought to involve an older H5N1 clade (2.3.2.1c) circulating in Cambodia and Vietnam, with the others due to the newer clade (2.3.4.4b) circulating globally.

H7 avian flu strikes Victoria layer farm

The national health department added that it is supporting Agriculture Victoria in its response to an outbreak at a poultry farm, which isn't related to the human case.

Separately, Australia's agriculture ministry today said the highly pathogenic avian influenza outbreak occurred at a layer farm near the Victoria city of Meredith, and testing have confirmed the H7 subtype. 

Agriculture secretary Murray Watt said in a statement though it's a relief that the strain isn't the same as the virus affecting other regions of the world such as the United States and Antarctica, Australia takes any incident involving highly pathogenic avian influenza seriously.

Australia experienced nine outbreaks in poultry involving highly pathogenic avian flu viruses between 1976 and 2021, according to Agriculture Victoria. In 2020 and early 2021, the state battled three different strains across three different local government areas, including highly pathogenic H7N7 at three layer farms, low pathogenic H5N2 at two turkey farms, and low pathogenic H7N6 at one emu farm.

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